JP2005351853A - Lightwave radar device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light wave radar device for enabling to measure the direction, velocity, and condition of wind with high precision of a plurality of observation spaces with different distances. <P>SOLUTION: The light wave radar device comprises a light transmit-receive part which sends a transmitting light in the air and obtains a receiving light by collecting the scattered light, a scan driving part which scans a optical path of the transmitting light in a predetermined direction, a receiving signal generating part which generates receiving signals by performing photoelectric conversion of the obtained receiving light, and a wind speed vector calculating part which detects a radial wind speed value by performing frequency conversion of the receiving signal and and calculates a wind speed vector from a plurality of the radial wind speed values and an output value of a corresponding elevation angle and an azimuthal angle. The scan driving part calculates scanning angles corresponding to the distances so that a plurality of points which are located at predetermined distances from the scan center are scanned on the basis of the distance between the installation position of the light wave radar device and an observation space, and scan the path of the transmitting light. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light wave radar apparatus that emits laser light into a space and measures the wind speed due to Doppler shift of scattered light accompanying the movement of aerosol in the space.

  Observation of the spatial distribution of wind speed has become an important observation item not only from meteorological observation and meteorological prediction, but also from the viewpoint of wind power represented by wind power generation facilities in recent years. Among them, the spatial distribution of wind speed near the ground surface is used to elucidate local weather mechanisms such as the heat island phenomenon, measure the urban environment typified by building winds, and investigate wind conditions before installing wind power generation facilities. There is a growing need for observation.

  As a representative example of wind speed distribution observation near the ground surface, the following describes wind condition surveys prior to the introduction of wind power generation facilities. When introducing wind power generation facilities, after conducting a location survey in a promising area, a wind condition review is conducted to estimate the amount of power generation based on continuous observation of the wind direction and wind speed in that area, and to evaluate the possibility of installation. Is done. Since the amount of wind power generation is proportional to the cube of the wind speed, sufficient observation accuracy is required for detailed wind conditions.

  As means for measuring a wind speed profile in the zenith direction from the ground surface, a wind condition measuring method using a weather radar RADAR (Radio Detection And Ranging) or a sound wave radar SODAR (SOund Detection And Ranging) has been recently proposed. Of these two measurement methods, in particular, the method using the sound wave radar SODAR is shown to be suitable for measuring a relatively low-rise wind condition having a small measurable distance and an altitude of about 100 m or less. (For example, refer nonpatent literature 1).

  This wind condition measurement method using an acoustic radar radiates sound waves in multiple directions toward the sky, receives sound waves back-scattered by the temperature gradient of the atmosphere above the sky, and measures the wind speed in the line of sight based on the Doppler shift. The wind direction and wind speed are calculated by vector calculation. Since it can measure the average of the wind field, it can be said that it is a suitable method for examining wind conditions.

  In order to measure a plurality of observation spaces by this acoustic radar, it is necessary to mechanically move the acoustic radar set in the zenith direction for each assumed point or to install it for each assumed point. However, the former takes time for movement and setting after installation, and the latter is unrealistic in terms of cost.

  On the other hand, there is an apparatus and a method for measuring a wind speed vector at a remote point using any of radio waves, sound waves, and light waves. For the observation space assuming a uniform wind direction and wind speed, set the scanning center at multiple elevation angles, measure the wind speed in the line of sight by cone scanning, horizontal scanning, and vertical scanning, and calculate the wind direction and wind speed by vector calculation from the measured values. A value is calculated (for example, refer to Patent Document 1).

  Among these, the method using the light wave has an advantage that the scanning center direction can be set up to near the horizontal because the transmission beam propagates without spreading. In addition, by moving the scanning center, wind direction and wind speed can be measured for a plurality of observation spaces, which is suitable for measuring wind conditions near the ground surface. As an effect of setting the scanning center at a plurality of elevation angles, the accuracy of the vertical wind speed component in a measurement space with a low elevation angle is improved.

"On the Theory of SODAR Measurement Techniques", Antoniou et al., Final report on WPI, EU WISE project NNE5-2001-297 (2003) Japanese Patent Laying-Open No. 2003-222673 (first page, FIG. 1)

  However, the prior art has the following problems. In the prior art using light waves, it is assumed that the wind speed in the line of sight is performed for each distance, but the cone angle of cone scanning, or the opening angle of horizontal scanning and vertical scanning is fixed independently of the measurement distance. For this reason, the farther away the observation space becomes, the more likely it is that the assumption of the uniformity of the wind velocity field is no longer valid. This has a problem that may cause a decrease in measurement accuracy when measuring wind direction and wind speed for a plurality of observation spaces with different distances such as a wind farm.

  In addition, when the scanning center direction is set parallel to the ground surface and conical scanning is performed at a fixed cone angle, the scanning rotation radius increases as the distance increases. As a result, the transmission optical path of the light wave radar is shielded by the ground. As a result, there was a problem that the wind conditions could not be measured.

  That is, as a method for remotely measuring the wind conditions near the ground surface (100 m or less) for a plurality of observation spaces having different distances, the conventional wind velocity vector measurement technique using a light wave radar is used. There is a problem that it is difficult to perform high-precision wind measurement due to uniformity, or that the measurement itself is difficult due to light path shielding.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to obtain a light wave radar apparatus capable of performing wind direction wind speed measurement and wind state measurement with high accuracy for a plurality of observation spaces having different distances. Objective.

  An optical radar device according to the present invention includes a light source unit that generates transmission light, an optical transmission / reception unit that emits the generated transmission light into the atmosphere, collects scattered light from the atmosphere, and extracts the received light as received light, and optical transmission / reception A scanning drive unit that scans the optical path of the transmission light emitted from the unit in a preset direction, a reception signal generation unit that photoelectrically converts the extracted reception light to generate a reception signal, and a frequency conversion of the reception signal The wind speed that detects the gaze direction wind speed value, reads the elevation angle and azimuth angle corresponding to the gaze direction wind speed value from the scanning drive unit, and calculates the wind speed vector from the detected plurality of gaze direction wind speed values and the corresponding elevation angle and azimuth angle A scanning calculation unit, based on the distance to the observation space, to calculate a scanning angle according to the distance so as to scan a plurality of points in the observation space that is a predetermined value away from the scanning center, Calculation Based on the scanning angle, the optical path of the transmitted light is scanned, and the wind speed vector calculation unit calculates the respective wind speed vectors corresponding to the azimuths of the multiple points of the scanned transmitted light, and combines the multiple wind speed vectors. The wind direction and wind speed in the observation space are calculated.

  According to the light wave radar apparatus of the present invention, the transmission light is scanned while changing the scanning angle according to the distance from the light wave radar apparatus to the observation space, so that the sizes of the plurality of observation spaces having different distances are all maintained constant. Thus, it is possible to obtain a light wave radar device capable of measuring the wind direction and the wind condition with high accuracy in an observation space where the uniformity of the wind velocity field is established.

  Hereinafter, preferred embodiments of a wind direction wind speed measuring method and a wind condition measuring method using an optical wave radar apparatus according to the present invention will be described with reference to the drawings. In the following description, the laser light emitted from the light wave radar device is referred to as transmission light.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of an optical wave radar device according to Embodiment 1 of the present invention. The light wave radar device 10 includes a light source unit 11, an optical transmission / reception unit 12, a scanning drive unit 13, a reception signal generation unit 14, and a wind speed vector calculation unit 15.

  The transmission light generated by the light source unit 11 is emitted from the optical transmission / reception unit 12 in a certain direction in the air. A part of the emitted transmission light is scattered by minute dust in the atmosphere, and a part of the scattered light is received by the optical transmission / reception unit 12 as reception light. Here, the direction of the transmission light emitted from the optical transmission / reception unit 12 is defined by the setting from the scanning drive unit 13. The scanning drive unit 13 controls the azimuth of the transmission light so as to scan a plurality of points at a predetermined distance from the scanning center with respect to the observation space. Scanning methods include cone scanning and linear scanning, the details of which will be described later.

The reception signal generation unit 14 converts the reception light received by the optical transmission / reception unit 12 into an electrical signal and generates a reception signal. Wind vector calculation unit 15, based on the received signal from the receive signal generator 14 detects a Doppler shift f _D by performing frequency analysis, and calculates a more eye direction wind velocity V _m corresponding to the orientation of the transmitted light . Assuming that the wavelength of the transmitted light is λ, the line-of-sight wind speed V _m is calculated by the following equation (1) using the Doppler shift f _D.

  Further, the wind speed vector calculation unit 15 calculates the wind direction wind speed at the scanning center by obtaining a vector composition of the line-of-sight direction wind speeds calculated for each of the transmission lights transmitted to a plurality of directions.

  In the light wave radar apparatus according to the first embodiment, the line of sight at a plurality of points that are always at a predetermined distance from the scanning center, regardless of the distance of the observation space position from the installation position of the light wave radar apparatus. Scanning light is scanned so that the direction wind speed can be calculated, and the wind direction wind speed at the scanning center is calculated based on the calculation result. Further, the present invention is characterized in that wind conditions are measured from wind directions and wind speeds calculated for a plurality of observation spaces by shifting the position of the scanning center.

  The details will be described next. In the following description, it is assumed that the functions of the light source unit 11, the optical transmission / reception unit 12, the scanning drive unit 13, the reception signal generation unit 14, and the wind speed vector calculation unit 15 are collectively implemented by the light wave radar apparatus. Describe.

  FIG. 2 is an explanatory diagram of a wind condition measuring method by the light wave radar apparatus in the first embodiment of the present invention. It is assumed that one parallel space is an observation space 115 with respect to the ground surface 101 in FIG. In this case, the observation space 115 may be either a closed space or an open space. Here, the maximum altitude from the ground surface of the observation space 115 is set to about 100 to 200 m. In the first embodiment, it is assumed that the wind direction and the wind speed in the observation space 115 at the time of measurement are uniform. First, a case where transmission light scanning is performed conically with respect to the scanning center will be described.

  The light wave radar device 102 is installed at a position separated from the observation space 115 by a distance R. The light wave radar device 102 scans the optical path of the transmission light 103 conically with respect to the observation space 115. At this time, the scanning center direction 104 of the cone scanning is made to coincide with the center of the observation space 115. If the cone angle of the cone scan is α, the transmitted light 103 passes through the optical path 105 on the circular ring with the diameter D in the observation space 115. When the cone angle α of the cone scan is fixed, the diameter D of the circle drawn by the locus of the transmission light 103 subjected to the cone scan at the distance R from the light wave radar apparatus 102 increases in proportion to R.

  Now, when the cone angle α is set to an angle represented by the following expression (2), the diameter D becomes a constant value regardless of the distance. That is, by making the cone angle α variable according to the distance R, the diameter D can be always constant even for observation spaces with different distances R.

  By performing conical scanning of the transmission light 103 in this way, the diameter D of the optical path 105 can be kept constant even when the distance R is increased or decreased, and as a result, the observation space is kept equal. And the uniformity of the wind velocity field can be avoided. After detecting a plurality of line-of-sight direction wind speeds in the optical path 105 determined in this manner, the wind direction wind speed at the center of the circle of the optical path 105 can be calculated by performing vector synthesis of the respective line-of-sight direction wind speeds. .

  Further, the above measurement is repeatedly performed by sequentially moving the scanning center direction 104 of the conical scanning with respect to the plurality of observation spaces 116 to 120 in a direction different from the observation space 115. Measuring the wind direction and wind speed by keeping the entire observation space 115 to 120 equal by performing conical scanning of the transmitted light 103 with the cone angle α being variable according to the distance between each observation space 116 to 120 and the light wave radar device 102. And wind conditions can be measured.

  Next, a wind speed vector calculation method in conical scanning will be described. FIG. 3 is an explanatory diagram of a wind speed vector calculation method according to Embodiment 1 of the present invention. A cone scanning coordinate system is defined by an xyz orthogonal coordinate system. Now, assuming that the unit vector [pi] 111 representing the emission direction (observation direction) of the i-th transmission light is [pi, qi, ri], the unit vector 111 has an elevation angle φi and an azimuth angle θi. Is represented by the following formula (3).

  Further, if the elevation angle in the scanning center direction 112 of the cone scanning is φc, the azimuth angle is θc, and the angle between the scanning center and the beam emission direction is α, the unit vector 111 is a composite of matrices representing rotations around the coordinate axes. And is represented by the following formula (4).

  Here, [Rz (ξ)], [Ry (ξ)], and [Rx (ξ)] are matrices for vector rotation by an angle ξ around the z-axis, y-axis, and x-axis, respectively. 5) to (7).

  As a result, the elevation angle φi and the azimuth angle θi in the beam emission direction at the time of conical scanning are expressed by the following equations (8) and (9).

  Here, atn2 (q / p) is represented by the following formula (10) that takes a range of 0 to 2π.

  Further, the wind speed vector [u] is defined by the following equation (11).

The model value V _di of the Doppler velocity corresponding to the ideal value to be observed in the emission direction pi of the i-th transmission light is a unit vector representing the wind speed vector [u] and the emission direction (observation direction) of the i-th transmission light. It is expressed by the following formula (12) as an inner product with [pi].

On the other hand, the visual line direction wind speed actual measurement value obtained from the actual measurement result of the received light is defined as V _mi . Now, let S be the sum of squares of the residual between the model value V _di of the Doppler velocity and the visual direction wind velocity measured value V _mi , the following equation (13).

  [U, v, w] that minimizes the residual sum of squares S is a wind speed vector estimated from the actually measured values. That is, the wind speed vector can be estimated by obtaining [u, v, w] that minimizes the residual sum of squares S based on the measured value. [U, v, w] that minimizes S is obtained by the following equations (14) to (17).

  Therefore, the equation (14) is expressed by the following equation (18).

  Here, the observation matrix [A] is represented by the following equation (19), and the output [Y] of the above equation (18) is represented by the following equation (20).

When the inverse matrix [A] ⁻¹ exists in the observation matrix [A], the wind speed vector [u] is calculated by the following equation (21) by multiplying both sides of the above equation (17) by [A] ⁻¹ from the left. Can be obtained.

Now, if the observation matrix [A] is replaced as in the following equation (22), the inverse matrix [A] ⁻¹ can be expressed by the following equations (23) and (24).

The condition for the existence of the inverse matrix [A] ⁻¹ is the following expression (25).

  From the values of the wind speed vector [u, v, w] obtained as described above, the wind speed | V |, the azimuth angle component θ of the wind direction, and the elevation angle component φ of the wind direction are respectively expressed by the following equations (26), (27), ( 28).

  Next, the flow of the measurement process will be described based on a flowchart. FIG. 4 is a flowchart showing the measurement process of the wind speed and direction according to Embodiment 1 of the present invention. First, the scanning center direction of the transmission light 103 of the light wave radar apparatus 102 is moved to the center position of the observation space 115 (step 401). At this time, the elevation angle of the scanning center of the cone scanning is φc, and the azimuth angle is θc. Further, an angle α formed by the scanning center and the emission direction of the transmission light 103 is set according to the equation (2) (step 402). Based on this condition, the light wave radar apparatus 102 performs conical scanning of the transmission light 103 (step 403).

The light wave radar apparatus 102 irradiates the transmission light having the wavelength λ while maintaining the above scanning state, and starts a calculation loop for acquiring the line-of-sight direction wind speed (step 404). In the calculation loop, the light wave radar device 102 receives scattered light from the aerosol existing in the observation space 115 as received light, converts the received light into an electric signal, and generates a received signal (step 405). Laser Radar device 102, by performing frequency analysis on the received signal, detecting a Doppler shift f _D, further calculates the gaze direction wind velocity V _m from the scattered light Doppler shift based on the equation (1) (step 406).

  Next, the wind velocity vector calculation unit 15 of the light wave radar apparatus 102 acquires the scanning angles φi, θi, γi, α (see FIG. 3) that define the emission direction of the transmission light corresponding to the received signal from the scanning drive unit 13. (Step 407). Next, the obtained scanning angles φi, θi, γi, α are applied to the equations (19) and (20) to calculate the elements of the observation matrix [A] and the observation vectors [y] (step 408).

Until the specified number of cone scanning Doppler velocities can be acquired, the above calculation is executed by repeating Steps 404 to 409 of the calculation loop. That is, the transmission light 103 is conically scanned, and the elements of the observation matrix [A] and the observation vector [y] are based on all the received signals in the designated number of emission directions and the scanning angles of all corresponding transmission lights. Will be asked. Thereafter, the inverse matrix [A] ⁻¹ of the observation matrix [A] is calculated using the equation (23) (step 410).

Finally, [A] ⁻¹ and [y] are calculated based on Expression (21) to calculate the wind speed vector [u], which is the calculation result of the first observation space 115 (step 411). . Next, it is determined whether or not the scanning center point is moved to the next observation space (step 412). If the scanning center point is moved, the process returns to step 401 to perform the subsequent processing. In this way, the calculation of the wind speed vector is repeated until the measurement in the necessary observation spaces 115 to 120 is completed.

  According to the first embodiment, by changing the cone angle of the cone scanning according to the distance from the light wave radar apparatus to the observation space, the light wave radar apparatus makes all the observation spaces constant in size regardless of the measurement distance. Measurement can be performed on the observation space where the uniformity of the wind velocity field is established, and the wind velocity error and the wind direction error associated with the vector calculation can be reduced.

  Furthermore, compared to the conventional point measurement with a cup-type anemometer, a wider space is observed, so if the measurement error is uncorrelated in the observation space, the number of gaze direction wind speed measurement points is increased. By performing smoothing, errors can be reduced.

Embodiment 2. FIG.
In the second embodiment, a case will be described in which preprocessing is performed when the line-of-sight direction wind velocity _Vm is calculated. Specifically, a case will be described in which threshold processing based on the signal-to-noise ratio (SNR) of the received signal is added as pre-processing for calculating the line-of-sight wind velocity V _m from the scattered light Doppler shift in step 406 of FIG. FIG. 5 is a flowchart of threshold processing based on the signal-to-noise ratio (SNR) of the received signal in Embodiment 2 of the present invention. FIG. 5 shows a case where threshold processing is added between step 405 and step 406 in FIG.

  Before calculating the Doppler velocity, the optical wave radar apparatus 102 first performs FFT processing on the received signal received in Step 405 to calculate a spectrum (Step 501). Further, peak frequency detection and SNR at the peak frequency are calculated for the calculated spectrum (step 502). Then, the light wave radar apparatus 102 determines whether or not the calculated SNR is within a preset effective range (step 503).

  The light wave radar apparatus 102 proceeds to Step 406 in FIG. 4 in order to calculate the Doppler velocity only when the calculated SNR is within the effective range. On the other hand, if the calculated SNR is outside the effective range, the lightwave radar device 102 discards the data acquired in that direction, returns to step 405 in FIG. 4, and returns the scattered light from the aerosol present in the observation space. It will be received again as received light.

  According to the second embodiment, by adding a preprocessing for discarding a received signal whose SNR is out of the effective range, a zero speed component detected at the time of shielding an optical path of a building or the like, or a wind speed erroneous detection component at a low SNR, It can be removed before the vector calculation process, and the reliability of the calculated data can be improved.

Embodiment 3 FIG.
In the first and second embodiments, a general wind condition measurement near the ground surface is assumed as an observation space. In the third embodiment, a case will be described in which the light wave radar apparatus of the first and second embodiments is applied to wind condition examination of a wind power generation facility. FIG. 6 is a diagram showing a configuration for performing a wind condition examination of the wind power generation facility according to Embodiment 3 of the present invention. That is, it is assumed that a horizontal wind power generation facility is installed in each of the observation spaces 215 to 220 in which the wind velocity field can be regarded as uniform.

  Here, the conical scanning center 204 of the transmission light 203 of the light wave radar apparatus 202 is made to coincide with the blade rotation center 210 of the assumed windmill of the horizontal wind power generation equipment, and the scanning of the conical scanning of the transmission light within the windmill blade surface is performed. The observation space is determined by setting the rotation radius to, for example, 10 to 200% of the rotation radius of the wind turbine blade, and the wind speed in the line of sight is measured. The wind direction and wind speed in the observation space are calculated by vector synthesis from the obtained measurement values of the wind speeds in the respective gaze directions.

Based on the obtained wind speed | V | and wind directions θ and φ, the incoming wind speed V _up of the wind turbine at the wind turbine assumed point Pc and the azimuth angle θc can be calculated from the following equation (29).

Furthermore, the energy obtained by the wind turbine can be calculated using the incoming wind speed V _up . The most basic calculation formula is given by the following formula (30).

  Here, ρ is the air density, Ω is the wind receiving area of the windmill, and Cp is the power coefficient. In particular, the power coefficient Cp is represented by the ratio of the power that can be extracted by the windmill and the power that the natural wind has, and the Betz coefficient of 0.593 is known as the theoretical limit value.

  According to the third embodiment, since the wind field effectively acting on the wind turbine blades can be effectively measured as compared with the point measurement by the conventional cup type anemometer, the prediction accuracy of the generated power can be improved. .

  Furthermore, if it is assumed that the wind velocity field is uniform in the conical scanned space, the estimation accuracy of the wind direction and the wind velocity depends on the measurement accuracy of the gaze direction wind velocity. Since the light wave radar apparatus according to the third embodiment calculates the wind speed vector based on a plurality of gaze direction wind speed measurement values, when the gaze direction wind speed measurement error is uncorrelated with the measurement value, the gaze direction The error can be reduced by increasing the number of measurement points and smoothing.

  In addition, the conical scanning center in the above measurement is sequentially moved with respect to the horizontal wind power generation facilities in the plurality of observation spaces, and the measurement is repeated, thereby making it possible to measure the wind conditions at a plurality of assumed wind turbine installation positions. It becomes possible. This makes it possible to measure wind conditions not only on flat terrain wind farms, but also in places where it is difficult to install conventional cup-type anemometers or sonic radars, such as mountainous areas with complicated terrain, coastlines with cliffs, and offshore. It becomes possible.

Embodiment 4 FIG.
In the first to third embodiments, the case where the wind direction wind speed is measured by scanning the transmission light from the light wave radar device in a conical shape under the assumption that the wind speed field is uniform in the observation space. On the other hand, in the fourth embodiment, it is assumed that only the wind direction is constant and the wind speed changes in the observation space, and the wind speed component in a specific direction is calculated from each gaze direction wind speed component by transmission light subjected to conical scanning. The case where it does is demonstrated. The installation location of the light wave radar device and the function of detecting the wind speed in the line-of-sight direction are the same as in the first to third embodiments, and a description thereof is omitted.

  As in the first to third embodiments, a space parallel to the ground surface 101 as shown in FIG. In this case, the observation spaces 115 to 120 may be either a closed space or an open space. Here, the maximum altitude from the ground surface of the observation spaces 115 to 120 is set to about 100 m. A relatively low-altitude atmospheric layer from the ground surface to about 100 m is called a ground layer in meteorology, and it is known that the wind direction is uniform, although the wind speed varies with altitude. In the fourth embodiment, considering these, it is assumed that only the wind direction is uniform.

  Similar to the first to third embodiments, the transmission light 103 is conically scanned with respect to each of the observation spaces 115 to 120. When the irradiation direction of the transmission light 103 is the same as that of the coordinate system of FIG. 3, the direction vector with respect to the irradiation direction is expressed in the same manner as Expression (3). If the elevation angle at the scanning center is φc, the azimuth angle is θc, the angle between the scanning center and the outgoing direction of the transmitted light is α, and the cone scanning rotation angle is γ, equation (3) can be rewritten as the following equation (31): .

  When performing conical scanning at a constant cone angle with the scanning center direction fixed, θc, φc, α are constant values, and the irradiation direction [pi] of the transmitted light is a function of the cone scanning rotation angle γ.

On the other hand, let the direction cosine of the wind velocity field in the observation space be [p _W ] represented by the following equation (32).

Since the wind direction is assumed to be constant, [p _W ] is a fixed value. When the absolute velocity of the wind velocity field corresponding to the irradiation direction [p _i ] of the i-th transmission light is | V _Wi |, the gaze direction wind velocity V _mi is obtained by using the inner product of [pi] and [p _W ], It is represented by the following formula (33). However, T represents transposition.

When the above equation (33) is modified, the absolute value of the wind speed | V _Wi | can be calculated as the following equation (34).

  Since it is assumed that the wind direction is constant, the wind speed component corresponding to the desired coordinate axis can be calculated by multiplying each component of the direction cosine of the wind direction. For example, the wind speed component parallel to the y-axis can be expressed by the following formula (35).

By performing the above measurement and calculation over the entire circumference of the cone scan, the wind speed component in the desired direction can be calculated even in an observation space where the absolute value of the wind speed | V _Wi | is not uniform.

  Next, specific measurement processing of the predetermined wind speed component will be described using a flowchart. FIG. 7 is a flowchart showing measurement processing of a predetermined wind speed component in the fourth embodiment of the present invention. First, the scanning center direction of the transmission light of the light wave radar apparatus is moved to the center position of the observation space (step 701).

  At this time, the elevation angle of the scanning center of the cone scanning is φc, and the azimuth angle is θc. Further, an angle α formed by the scanning center and the transmission light emission direction is set according to the equation (2) (step 702). Based on this condition, the light wave radar device performs conical scanning of the transmitted light (step 703).

The light wave radar apparatus irradiates the transmission light having the wavelength λ while maintaining the above-described scanning state, and starts a calculation loop for acquiring the visual direction wind speed (step 704). In the calculation loop, the light wave radar device receives scattered light from the aerosol present in the observation space as received light, converts the received light into an electrical signal, and generates a received signal (step 705). Laser Radar apparatus calculates the gaze direction wind velocity _{V m} (step 706). Next, the wind velocity vector calculation unit 15 of the light wave radar apparatus 102 acquires the scanning angles φi, θi, γi, α (see FIG. 3) that define the emission direction of the transmission light corresponding to the received signal from the scanning drive unit 13. (Step 707).

Next, the obtained scanning angles φi, θi, γi, α are applied to the equation (31) to calculate the direction vector [p _i ] (step 708). Based on the calculated line-of-sight direction wind speed V _m , the direction vector [p _i ], and the wind direction value [p _W ] obtained by the previous expression (32), the wind speed in a predetermined direction is calculated by applying the expression (35) (step 709). .

  Until the designated number of conical scanning Doppler velocities can be obtained, Steps 704 to 710 of the calculation loop are repeated, and the above calculation is executed. A wind speed component distribution in a specific direction is obtained from the specified number of measurement results. Furthermore, the average wind speed component in a specific direction can be obtained by averaging the specified number of measurement results.

  Next, as in the case of the first embodiment, it is determined whether or not the scanning center point is moved to the next observation space (step 711), and if it is moved, the process returns to step 701, and the subsequent processing is performed. Do. In this way, the calculation of the wind velocity component in a specific direction is repeated until the measurement in the required observation space is completed.

  According to the fourth embodiment, it is possible to measure a wind speed component distribution in a specific direction in an observation space where the wind speed is not uniform under the assumption that the wind direction is uniform. Further, similarly to the first to third embodiments, an observation space having an equal size can be defined regardless of the observation distance, and the uniformity of the wind direction can be ensured. Further, by averaging the plurality of data of the wind speed components in the specific direction, the average wind speed components at a plurality of points in the observation space can be obtained.

Embodiment 5 FIG.
In the fifth embodiment, a case will be described in which the light wave radar device of the fourth embodiment is applied to wind condition examination of a wind power generation facility. When the light wave radar apparatus according to the fourth embodiment is applied to the wind condition examination of a horizontal wind turbine for wind power generation, it is possible to measure the difference in wind speed in the wind turbine blade surface, so that more accurate power generation prediction is possible. I can expect.

  That is, as shown in FIG. 6, the scanning center of the conical scanning is made coincident with the assumed blade rotation center of the windmill, and the rotational radius of the conical scanning is made coincident. In this case, the direction-of-arrival component of the line-of-sight wind speed obtained by conical scanning corresponds to the selective measurement of the wind speed field arriving at a specific radial position of the wind turbine blade.

  FIG. 8 is a diagram illustrating an example of a lift distribution generated on the wind turbine blades when the wind velocity field is input to the horizontal wind turbine blades. FIG. 8A shows the lift distribution 23 when the blade pitch angle of the blades 21 of the horizontal wind turbine is controlled in accordance with the wind speed of the wind velocity field 22 input to the wind turbine. Further, FIG. 8B shows lift distributions 24 to 26 when stall control is performed with the blade pitch angle of the blades 21 of the horizontal wind turbine fixed.

  The lift distribution 24 in FIG. 8B shows the lift distribution at a wind speed of 9 m / s, the lift distribution 25 shows the lift distribution at a wind speed of 12 m / s, and the lift distribution 26 has a wind speed of 24 m / s. The lift force distribution in is shown. 8A and 8B, the lift distributions 23 to 26 generated in the blade are zero on the blade rotation center axis and have a convex characteristic with respect to the blade radial direction. I understand that.

  For example, the gaze direction wind speed is measured by matching the radius of rotation of the conical scanning on the assumed windmill surface with the blade radial position that is the maximum lift in the pitch angle control method of FIG. The incoming wind speed component obtained in this case is considered to include more components contributing to the rotation of the windmill even when the wind speed arriving in the windmill blade surface is not uniform, and the accuracy of power generation prediction is improved.

  On the other hand, for the wind turbine of the stall control method shown in FIG. 8 (b), the blade radial position at which the maximum lift force may be different depending on the wind speed arriving in the wind turbine surface. The blade radial position for maximum lift varies depending on the blade shape and pitch fixed angle, but the above characteristics can be estimated to some extent from the design value of the wind turbine blade.

  For this reason, the light wave radar device stores in advance the data on the blade radial position characteristics that obtain the maximum lift with respect to the incoming wind speed in the storage unit, and the cone is placed at the radial position that provides the maximum lift according to the measured incoming wind speed. By changing the rotation radius of scanning, it is possible to recalculate the wind speed component in accordance with the characteristics.

  According to the fifth embodiment, the wind speed component contributing to the windmill rotation can be selectively measured even in the case of stall control. As a result, it is possible to measure the wind speed component that effectively contributes to the rotation of the windmill, as compared with the measurement in which the rotation radius of the conical scanning is constant, and it is possible to improve the power generation amount prediction accuracy.

  Note that the measurement of the wind speed component distribution in the specific direction can also be calculated for a plurality of cone scanning radii as described in Embodiment 3 assuming the installation of a horizontal wind power generation facility. This makes it possible to measure the wind speed component for a plurality of rotation radii compared to the measurement in which the rotation radius of the conical scanning is constant, thereby improving the power generation amount prediction accuracy.

Embodiment 6 FIG.
In the first embodiment, the case has been described in which the wind direction and wind speed are measured by scanning the transmission light from the light wave radar device in a conical shape under the assumption that the wind speed field is uniform in the observation space. On the other hand, in this Embodiment 6, the case where transmission light is scanned left and right in parallel with the ground surface will be described. The installation location of the light wave radar device and the function of detecting the wind speed in the line-of-sight direction are the same as in the first embodiment, and a description thereof is omitted.

  FIG. 9 is a diagram showing a configuration for performing a wind condition examination of the wind power generation facility according to the sixth embodiment of the present invention. In the sixth embodiment, the case where the wind speed field of the horizontal wind power generation facility is applied will be described. However, any observation space in which the wind velocity field can be regarded as uniform can be used. Anywhere.

  With respect to each of the observation spaces 315 to 320 having a uniform wind direction and wind speed, the transmission lights 303a and 303b are scanned in a straight line parallel to the ground surface and passing through the scanning center direction 304. The line-of-sight wind speed is measured in the direction corresponding to the point, and the wind direction and wind speed are calculated by vector synthesis. Here, the scanning center 304 in the assumed windmill blade surface in the observation space is made to coincide with the windmill blade rotation center 310.

  Next, the wind speed vector calculation method in the left and right scanning will be specifically described. FIG. 10 is an explanatory diagram of a wind speed vector calculation method according to the sixth embodiment of the present invention. A coordinate system is defined by an xyz orthogonal coordinate system. In FIG. 10A, the outgoing light of the transmission light is scanned from −α to + α in the azimuth direction around the scanning center 304 (azimuth angle θc, elevation angle φc). Here, as an outgoing azimuth of the transmission light in FIG. 10, an outgoing azimuth of the transmission light 303a having an azimuth angle of θc + α is defined as an outgoing azimuth 1, and an outgoing azimuth of the transmission light 303b having an azimuth angle of θc−α is defined as an outgoing azimuth 2. Define.

In FIG. 10 (b), _assuming that the wind speeds in the line-of-sight directions of the outgoing azimuths 1 and 2 are V _m1 and V _m2 , respectively, a wind speed component V _// 311 parallel to the ground surface and parallel to the scanning center azimuth direction; scanning central azimuth direction perpendicular wind component V _⊥ 312 is the following formula, respectively (36) is represented by (37).

Accordingly, the wind speed | V _hor | and the wind direction θ in a plane parallel to the ground surface are calculated by the following equations (38) and (39).

  This makes it possible to calculate the wind direction and wind speed in the horizontal plane with respect to the ground surface from the two line-of-sight wind speeds.

  FIG. 11 is a flowchart showing the measurement process of the wind speed and the wind direction according to the sixth embodiment of the present invention. First, the scanning center direction of the transmission light of the light wave radar apparatus 302 is moved to the center position of the observation space 315 (step 1101). At this time, the elevation angle of the scanning center of the cone scanning is φc and the azimuth angle is θc. Further, as a value corresponding to the cone angle α in the conical scanning, a half angle α of the opening angle in the left and right scanning is set according to the equation (2) (step 1102). Based on this condition, the light wave radar apparatus 302 performs left and right scanning of the transmitted light (step 1103).

The light wave radar apparatus 302 irradiates the transmission light having the wavelength λ while maintaining the above-described scanning state, and starts a calculation loop for acquiring the line-of-sight direction wind speed (step 1104). In the calculation loop, the light wave radar device 302 receives scattered light from the aerosol present in the observation space 315 as received light, converts the received light into an electrical signal, and generates a received signal (step 1105). The light wave radar apparatus 302 calculates the i-th Doppler velocity V _m (i) in the loop (step 1106). Further, the wind velocity vector calculation unit 15 of the light wave radar apparatus 302 acquires the emission azimuth angle (see FIG. 10) that defines the emission direction of the transmission light corresponding to the received signal from the scanning drive unit 13 (step 1107).

Next, by applying the line-of-sight wind speeds V _m (i-1) and V _m (i) for two consecutive times and the half angle α of the opening angle of the left and right scanning to the equations (36) and (37), the horizontal wind A component and a circular direct wind component are calculated. Further, the wind speed | V _hor | and the wind direction θ in the i-th measurement are calculated using the equations (38) and (39) (step 1108).

  Until the designated number of left-right scanning Doppler velocities can be acquired, Steps 1104 to 1109 of the calculation loop are repeated, and the above calculation is executed.

  Next, as in the case of the first embodiment, it is determined whether or not the scanning center point is moved to the next observation space (step 1110). If it is moved, the process returns to step 1101, and the subsequent processing is performed. Do. In this manner, the measurement of the wind direction and the wind speed is repeatedly performed until the measurement in the necessary observation spaces 315 to 320 is completed.

  As in the case of the first embodiment, by setting the left-right scanning opening angle α in accordance with the distance R from the light wave radar apparatus 302 to the observation space according to the equation (2), the light wave radar apparatus 302 can measure the distance measured. Regardless of this, it is possible to measure the wind direction and wind speed for a certain observation space, and to ensure the uniformity of the wind direction.

In the case of wind direction and wind speed measurement by conical scanning according to the first embodiment, the observation matrix [A] and its inverse matrix [A] ⁻¹ are calculated from the measurement azimuths at N points, and multiplied by the measurement values of the wind speeds in the respective gaze directions. I asked for the wind direction and wind speed. On the other hand, in the case of wind direction wind speed measurement by left and right scanning according to the sixth embodiment, the wind direction wind speed is calculated from the measured values of the wind speed in the two line-of-sight directions, so that the calculation can be simplified. Thereby, there is an advantage that the gaze direction wind speed measurement time and calculation time required for one wind direction wind speed calculation can be shortened and the measurement update time can be shortened.

Next, the wind speed calculation accuracy based on the measured values of the wind speed in the two gaze directions will be described. _{Assuming that} the measurement errors of the line-of-sight wind speeds V _m1 and V _m2 are ΔV _m1 and ΔV _m2 , respectively, the wind speed component V _// parallel to the ground surface and parallel to the scanning center azimuth direction is expressed by the following equation (40). A measurement error ΔV _// is generated as shown.

The variance of the error ΔV _// is expressed by the following equation (41).

However, the notation <> in the above formula (41) represents a set average. Now, when α << 1 (that is, when α is sufficiently small), the standard deviation of ΔV _// can be approximated by the following equation (42).

Here, ε _V represents the standard deviation of ΔV _m1 and ΔV _m2 as represented by the following equation (43), and is uncorrelated as ΔV _m1 and ΔV _m2 are represented by the following equation (44). It was supposed to be.

Similarly, a wind speed component V _平行 parallel to the ground surface and perpendicular to the scanning center azimuth direction causes a measurement error ΔV _{よ う}な as shown in the following equation (45).

The variance of ΔV _⊥ is expressed by the following equation (46).

When Arufa«1, the standard deviation of the [Delta] V _⊥ can be approximated by the following equation (47).

Based on the above results, the calculation accuracy of the wind speed | V _hor | in the plane parallel to the ground surface will be considered. The influence of the error of [Delta] V _// and [Delta] V _⊥, when the calculation error only [Delta] V _hor occurs, the relation of the following equation (48).

When both sides of the above equation (48) are squared and approximated under the condition of ΔV _hor << 1 (that is, when ΔV _hor is sufficiently small), the following equation (49) is obtained.

As shown in FIG. 10B, when δ is defined by an angle formed by the wind direction and the scanning center direction, ΔV _hor is expressed by the following equation (50).

  Therefore, the standard deviation of the wind speed is expressed by the following formula (51).

Here, the correlation coefficient between the [Delta] V _// and _{ΔV ⊥ <ΔV // · ΔV ⊥} > becomes the following equation (52).

  Further, the above equation (51) is represented by the following equation (53).

Therefore, when the scanning center direction is parallel to the wind direction (δ = 0), the wind speed calculation error ΔV _hor is minimized, and conversely, when the scanning center direction is perpendicular to the wind direction (δ = 90 °), the wind speed is The calculation error ΔV _{hor of} is maximum. Further, the larger the opening angle 2α of the left and right scanning, the smaller the wind speed calculation error.

Next, the wind direction calculation accuracy based on the measured values of the two gaze direction wind speeds will be described. The influence of the error of [Delta] V _// and [Delta] V _⊥, if Δθ only wind direction calculation error occurs, represented by the following formula (54).

  At this time, the wind direction measurement error Δθ is expressed by the following equation (55).

_{However, V // »ΔV //,} assuming V _⊥> ΔV _⊥, it is assumed that the condition of the formula (56) is established.

Considering the case where the wind speed to be measured is perpendicular to the scanning center direction, that is, the case of V _// = 0, Δθ is expressed by the following equation (57).

  Therefore, the standard deviation of the wind direction error can be approximated to the following equation (58) by the equations (42) and (57).

On the other hand, if the wind speed to be measured is perpendicular to the scanning center direction, namely consider the case of a V _⊥ = 0, the standard deviation and the wind speed error Δθ, respectively formula (59) can be approximated as equation (60) .

  Since it is assumed that the deflection angle α is 90 degrees or less, the minimum value is obtained when the wind direction is perpendicular to the scanning center direction, and the maximum value is obtained when the wind direction is parallel to the scanning center direction.

  As described above, when the wind direction to be measured is parallel to the scanning center direction, the standard deviation of the wind speed error is minimum and the standard deviation of the wind direction error is maximum. Conversely, when the wind direction is perpendicular to the scanning center direction, it can be seen that the standard deviation of the wind speed error is the maximum and the standard deviation of the wind direction error is the minimum.

  According to the sixth embodiment, the gaze direction wind speed measurement for obtaining one wind velocity vector may be two gaze directions, and the calculation can be simplified as compared with the wind direction wind speed measurement by the cone scanning described in the first embodiment. . Thereby, there is an advantage that the gaze direction wind speed measurement time and calculation time required for one wind direction wind speed calculation can be shortened and the measurement update time can be shortened.

  In addition, when the topography of the measurement area is complicated, or when an obstacle such as a building blocks a part of the optical path of the transmitted light during conical scanning and there is no optical path shielding in the horizontal direction, etc. There is an advantage that the utilization rate of measurement data can be increased.

  In addition, with respect to the signal integration average described in the first embodiment, the integration average processing is performed on the wind direction and the wind speed calculated from the two line-of-sight directions, or each line-of-sight direction wind speed is separately calculated and integrated. The wind direction and wind speed may be calculated from the average line-of-sight direction wind speed value using equations (31) to (33).

  In addition, in the case of the average calculation, as in the first embodiment, a threshold value process is performed in which an effective range is set for the signal-to-noise ratio of each gaze direction wind speed measurement value, and data outside the effective range is rejected. Can be added. Thereby, the zero speed component detected by the light path shielding and the erroneous detection component at the time of low SNR can be excluded, and the reliability in calculating the wind direction and the wind speed can be improved.

Embodiment 7 FIG.
In the sixth embodiment, the case has been described in which the wind direction and wind speed are measured by scanning the transmitted light from the light wave radar device in the horizontal direction parallel to the ground surface under the assumption that the wind speed field is uniform in the observation space. On the other hand, in this Embodiment 7, the case where transmission light is scanned up and down with respect to the ground surface is demonstrated. The installation location of the light wave radar device and the function of detecting the wind speed in the line-of-sight direction are the same as in the first embodiment, and a description thereof is omitted.

  FIG. 12 is a diagram showing a configuration for conducting a wind condition examination of the wind power generation facility according to Embodiment 7 of the present invention. In the seventh embodiment, as an example of an observation space where the wind direction and wind speed are uniform, it is assumed that the horizontal wind power generation facility is applied to wind condition examination, and the transmitted light is scanned in a straight line with respect to the ground surface. The case of measuring the wind speed in the line of sight with respect to the direction corresponding to two points on a straight line will be described. However, any observation space where the wind velocity field can be considered uniform is applicable, whether it is a closed space or an open space. Good.

  For each of the observation spaces 415 to 420 in which the wind direction and the wind speed are uniform, the transmission lights 403a and 403b are scanned in a straight line perpendicular to the ground surface and passing through the scanning center direction 404. The gaze direction wind speed is measured with respect to the direction corresponding to the point, and the horizontal wind component and the circular straight wind component are calculated by vector synthesis. Here, the scanning center 404 in the assumed windmill blade surface in the observation space is made to coincide with the windmill blade rotation center 410.

  Next, the wind speed vector calculation method in the vertical scanning will be specifically described. FIG. 13 is an explanatory diagram of a wind speed vector calculation method according to Embodiment 7 of the present invention. A coordinate system is defined by an xyz orthogonal coordinate system. In FIG. 13A, the outgoing light of the transmission light is scanned from −α to + α in the elevation direction around the scanning center 404 (azimuth angle θc, elevation angle φc). Here, as the outgoing azimuth of the transmission light in FIG. 13, the outgoing azimuth of the transmission light 403a having an elevation angle of φc + α is defined as an outgoing azimuth 1, and the outgoing azimuth of the transmission light 403b having an elevation angle of φc−α is defined as an outgoing azimuth 2. .

In FIG. 13 (b), _assuming that the wind speeds in the line-of-sight directions of the outgoing azimuths 1 and 2 are V _m1 and V _m2 , respectively, a wind speed component V _// 411 that is parallel to the ground surface and parallel to the scanning center azimuth direction; scanning central azimuth direction perpendicular wind component V _⊥ 412 becomes a notation interchanging the elevation φc and azimuth angle θc in the second embodiment, the following formula, respectively (61) is expressed as (62).

Accordingly, the wind speed | V _ver | and the wind direction φ in a plane parallel to the ground surface are calculated by the following equations (63) and (64).

  Thereby, the wind direction wind speed in the vertical plane with respect to the ground surface can be calculated from the two line-of-sight direction wind speeds.

  FIG. 14 is a flowchart showing the measurement process of the wind speed and the wind condition according to the seventh embodiment of the present invention. First, the scanning center direction of the transmission light of the light wave radar apparatus 402 is moved to the center position of the observation space 415 (step 1401). At this time, the elevation angle of the scanning center of the cone scanning is φc, and the azimuth angle is θc. Further, as a value corresponding to the cone angle α in the cone scan, the half angle α of the opening angle in the vertical scan is set according to the equation (2) (step 1402). Based on this condition, the light wave radar apparatus 402 performs vertical scanning of the transmitted light (step 1403).

The light wave radar device 402 irradiates the transmission light having the wavelength λ while maintaining the above scanning state, and starts a calculation loop for acquiring the line-of-sight direction wind speed (step 1404). In the calculation loop, the light wave radar device 402 receives scattered light from the aerosol present in the observation space 415 as received light, converts the received light into an electrical signal, and generates a received signal (step 1405). The light wave radar device 402 calculates the i-th Doppler velocity V _m (i) in the loop (step 1406). Further, the wind velocity vector calculation unit 15 of the light wave radar apparatus 402 acquires the emission azimuth angle (see FIG. 13) that defines the emission direction of the transmission light corresponding to the received signal from the scanning drive unit 13 (step 1407).

Next, by applying the line-of-sight wind speeds V _m (i−1) and V _m (i) for two consecutive times and the half angle α of the open / closed scanning angle to the equations (61) and (62), the horizontal wind A component and a circular direct wind component are calculated. Further, the wind speed | V _ver | and the wind direction φ in the i-th measurement are calculated using the equations (63) and (64) (step 1408).

  Until the designated number of vertical scanning Doppler velocities can be acquired, Steps 1404 to 1409 of the calculation loop are repeated, and the above calculation is executed.

  As in the case of the first embodiment, it is determined whether or not the scanning center point is moved to the next observation space (step 1410). If it is moved, the process returns to step 1401, and the subsequent processing is performed. In this way, the measurement of the wind direction and the wind speed is repeatedly performed until the measurement in the necessary observation spaces 415 to 420 is completed.

  According to the seventh embodiment, as in the case of the first embodiment, by setting the vertical scanning opening angle α according to the equation (2) according to the distance from the light wave radar apparatus to the observation space, the light wave radar The apparatus can measure a fixed observation space regardless of the measurement distance, and can ensure the uniformity of the wind direction.

  Further, as in the case of the sixth embodiment, in the case of the wind direction and wind speed measurement by the vertical scanning according to the seventh embodiment, the calculation is simplified because the wind direction and wind speed are calculated from the measurement values of the two gaze direction wind speeds. it can. Thereby, there is an advantage that the gaze direction wind speed measurement time and calculation time required for one wind direction wind speed calculation can be shortened and the measurement update time can be shortened.

  Further, the measurement accuracy can be considered in the same manner as in the sixth embodiment, and the calculation accuracy of the wind speed is higher and the calculation accuracy of the wind direction is lower as the measured wind direction is closer to being parallel to the scanning center azimuth direction. Conversely, the closer the wind direction to be measured is to the direction perpendicular to the scanning center azimuth direction, the lower the wind speed calculation accuracy and the higher the wind direction calculation accuracy.

  Furthermore, the reliability of the calculated wind speed data can be improved by the averaging process and the threshold process described in the sixth embodiment.

  One of the causes of fatigue of wind power generation facilities is considered to be the wind speed in the vertical direction. Especially in complicated terrain, the disturbance of the wind speed field is large, and the estimation error by the numerical simulation becomes large. In the seventh embodiment, the wind speed in the vertical direction can be measured, which is effective for analysis of the wind speed field and prediction of fatigue analysis of the windmill.

  Furthermore, the wind speed in the vertical direction obtained in the seventh embodiment is effective for the design and fatigue analysis of towers and structures to be constructed in the wind condition examination for offshore wind power generation.

Embodiment 8 FIG.
In the first to seventh embodiments, the transmitted light from the light wave radar device is spatially scanned (conical scanning, left and right scanning, and vertical scanning). In the eighth embodiment, specific implementation of such spatial scanning is performed. An example of the method will be described.

  FIG. 15 is an explanatory diagram of a transmission light scanning method by the wedge prism according to the eighth embodiment of the present invention. Now, as shown in FIG. 15A, the scanning mechanism unit 502 is installed on the object side of the objective-side opening of the sensor head 501, so that transmission is performed at an angle α with respect to the rotational symmetry axis (optical axis) of the sensor head. Consider a case where light 503 is deflected.

As a specific implementation example of the scanning mechanism, there is a wedge prism 504 shown in FIG. Consider the case where the angle between the incident side and the exit side surface is transmitted light 505 incident on the wedge prism 504 of [psi _0. The deflection angle α obtained by the wedge prism 504 is given by the following formula (65) according to Snell's law.

  Therefore, by rotating the wedge prism 504 in the azimuth direction around the optical axis of the sensor head 501, it is possible to scan conically.

With one rotation of the wedge prism 504, only conical scanning with a deflection angle α determined by the wedge angle ψ ₀ is possible, but by combining two wedge prisms 504, conical scanning or linear scanning with a deflection angle α or less. Is possible. Hereinafter, a scanning method by combining two wedge prisms 504 will be described.

  FIG. 16 is an explanatory diagram of the spatial scanning in the eighth embodiment of the present invention. It is assumed that the two wedge prisms 504a and 504b are wedge A and wedge B, respectively, and the deflection angle by each wedge prism is α.

  First, it is assumed that θc = 0 and φc = 0 shown in the coordinate definition of FIG. The origin of the wedge prism is defined when the direction in which the wedge prisms 504a and 504b have the maximum thickness is in the + y-axis direction, and the counterclockwise direction is defined as a positive sign as the rotation direction of the wedge prism.

Next, when the wedge prisms 504a and 504b are rotated at the initial phases γ ₀ and −γ ₀ having the same speed and the same sign but different speeds and γ _A (t) and γ _B (t), transmitted light is transmitted. The y component β _y (t) and the z component β _z (t) of the emission azimuth are expressed by the following equations (66) and (67).

Here, as in the following formulas (68) and (69), the rotational speeds of the wedge prisms 504a and 504b have the same sign and the same speed, and the initial phase γ ₀ is 0.

In this case, the outgoing direction (β _y (t), β _z (t)) of the transmission light is a conical scan 507 with a deflection angle 2α as represented by the following equations (70) and (71). Such a spatial scan corresponds to the conical scan in FIG.

Further, as in the following equations (72) and (73), the rotational speeds of the wedge prisms 504a and 504b are set to the same sign and the same speed, and the initial phase γ _{0 is set} to 0.

In this case, the outgoing direction (β _y (t), β _z (t)) of the transmission light is a straight line having an amplitude ± 2α parallel to the y direction as represented by the following equations (74) and (75). Scanning (left / right scanning) 508 is performed. Such a spatial scan corresponds to the left-right scan in FIG.

  Further, as shown in the following equations (76) and (77), the rotational speeds of the wedge prisms 504a and 504b are set to the same sign and the same speed, and the initial phase is set to 90 °.

In this case, the outgoing direction (β _y (t), β _z (t)) of the transmission light is a straight line having an amplitude ± 2α parallel to the y direction as represented by the following equations (78) and (79). Scanning (vertical scanning) 509 is performed. Such a spatial scan corresponds to the vertical scan in FIG.

  As described above, conical scanning and linear scanning (horizontal scanning and vertical scanning) are possible by combining the rotation directions of the two wedge prisms 504a and 504b and selecting the initial phase of 0 ° and 90 °.

On the other hand, when the rotational speeds of the wedge prisms 504a and 504b are set to the same speed and in the same direction, and an arbitrary initial phase γ ₀ is given in the range of ₀ to 90 °, the emission azimuth of transmission light (β _y (t) , Β _z (t)) is conical scanning with a deflection angle of 2α cos γ ₀ as represented by the following equations (80) and (81).

FIG. 17 is a diagram showing the trajectory of the scanning direction by conical scanning with the deflection angle 2αcosγ _{0 in} the eighth embodiment of the present invention. Three kinds of trajectories 510 to 512 of the scanning azimuth in the cone scanning with such a deflection angle are shown in the yz coordinate system. 17A shows a trajectory 510 when the initial phase is γ ₀ = 0, FIG. 17B shows a trajectory 511 when the initial phase is 0 ° <γ ₀ <60 °, and FIG. 17C. Respectively show trajectories 512 when the initial phase is 60 ° <γ ₀ <90 °.

The locus 510 whose initial phase is γ ₀ = 0 can set the deflection angle to the locus maximum deflection angle 2α. The locus 511 having an initial phase of 0 ° <γ ₀ <60 ° can set the deflection angle in the range of α to 2α. The trajectory 512 whose initial phase is 60 ° <γ ₀ <90 ° can set the deflection angle in the range of ₀ to α.

  The condition for scanning the transmitted light on the circumference of the diameter D with respect to the observation space at the measurement distance R using the two wedge prisms 504a and 504b having the deflection angle α is expressed by the following equation (82). The

When the above equation is solved for γ ₀ , the following equation (83) is obtained.

By appropriately selecting the deflection angle α, it is possible to perform measurement while maintaining the rotation radius D / 2 of the cone scanning constant for observation spaces having different measurement distances R. FIG. 18 is an explanatory diagram relating to the trajectory of conical scanning in the eighth embodiment of the present invention. By appropriately selecting the deflection angle α for the two measurement distances L _n and L _{n + 1} , the trajectories 551 and 552 of the respective scanning directions in the cylindrical closed space 550 are maintained at the same turning radius. Can do. In this way, measurement of wind direction and wind speed by conical scanning at different positions can be performed while maintaining the same rotation radius.

  Further, in the wind condition measurement in the wind farm, the transmitted light can be scanned with the same cone scanning radius with respect to a plurality of assumed wind turbine installation positions at different distances, and the wind velocity field that effectively contributes to the wind turbine rotation can be measured. Thereby, there exists an effect which can improve the estimation precision of electric power generation amount.

Two wedge prism 504a for performing conical scanning, the rotation of 504b is wedge prism 504a, after the angular difference between the origin of 504b was fixed to the way one rotating plate on the 2 [gamma _0, the rotary plate It can be realized easily by rotating.

In addition, two phase-controllable electric motors are independently installed for the respective wedge prisms 504a and 504b and rotated, and the rotation angle of the rotating wedge prism is measured, and the difference between the measured values is constant. it may be dynamically controlled to a value 2 [gamma _0. This makes it possible to control the beam trajectory of the conical scanning on the same circumference while moving the scanning center direction.

  On the other hand, a method for making the distance of the linear scanning range constant in the horizontal scanning or the vertical scanning will be described next. FIG. 19 is a diagram showing a time waveform of the scanning angle in the eighth embodiment of the present invention. The 2α cos γ (t) on the right side of the expression (74) representing the scanning angle in the case of the left-right scanning or the right side of the expression (79) representing the scanning angle in the case of the up-down scanning is periodically changed with the time waveform 560 shown in FIG. . This time waveform is defined for each measurement distance R when the distance D of the linear scanning range is set to a desired constant value.

  Here, one gaze direction wind speed in the two gaze directions is measured in the range of t1 <t <t2, and the other gaze direction wind speed in the two gaze directions is measured in the range of t3 <t <t4. Acquisition timing can be assigned. Thereby, the scanning opening angle of the linear scanning can be kept constant regardless of the distance to the observation space.

  In FIG. 19, the time waveform of the scanning angle is trapezoidal, but any waveform can be used as long as the optical path scanning angle becomes ± arctan [D / 2R] at the acquisition time of the reception signal in two directions.

  According to the eighth embodiment, cone scanning and linear scanning (vertical scanning and horizontal scanning) can be performed by one scanning mechanism, and the cone angle of linear scanning and the opening angle of linear scanning can be set regardless of the measurement distance. Can be kept constant.

  Furthermore, when measuring the wind direction and wind speed by conical scanning and linear scanning for observation spaces with different measurement distances, the observation space can be kept constant, and the uniformity of the wind velocity field due to the expansion of the observation space can be maintained. Failure can be prevented.

  Furthermore, even when measuring the wind direction and wind speed in a pipe-shaped closed space extending in the depth direction by conical scanning and linear scanning, the conical angle of linear scanning and the opening angle of linear scanning should be kept constant regardless of the measurement distance. Can do. Further, when installing horizontal wind turbines at different distances in the wind farm, it is possible to perform conical scanning similar to the wind turbine blade diameter, which is effective for improving the accuracy of power generation prediction.

Embodiment 9 FIG.
In the first, sixth, and seventh embodiments, the case where it is assumed that the wind velocity field is uniform as the observation space has been described. In the ninth embodiment, a method for automatically setting an observation space that can ensure the uniformity of the wind velocity field will be described.

First, with the cone angle of the cone scan minimized, the line-of-sight wind velocity V _mi and the cone scan rotation angle γ _i are measured by cone scan with respect to the observation space. Further, assuming the uniformity of the wind speed field, the wind speed vector [u] is calculated based on the equation (21). Further, the line-of-sight direction [pi] is calculated by applying the cone scanning rotation angle γ _i and the scanning center direction (θc, φc) to the equation (3). Next, using the calculated wind speed vector [u] and the line-of-sight direction [pi], the inner product calculation shown in Expression (12) is performed to calculate the estimated value V _di of the line-of-sight direction wind speed.

The residual between this estimated value V _di and the measured gaze direction wind speed V _mi is calculated using equation (13), and the average value and standard deviation of the residual are calculated. When the assumption of the uniformity of the wind direction and wind speed is fully established in the observation space, the residual obtained as described above is zero. On the other hand, the residual increases as the assumption of uniformity breaks down.

  Since the uniformity of the wind field is thought to collapse as the observation space expands, the residual that is calculated when the cone angle is gradually expanded is monitored, and the residual that can be regarded as uniform wind speed. Search for the maximum cone angle where the standard deviation of is within the specified value. When the cone angle is set within the maximum cone angle obtained by such search processing, it is possible to perform the wind direction and wind speed calculation while ensuring the uniformity of the wind.

  FIG. 20 is a flowchart showing an observation space setting process capable of ensuring the uniformity of the wind velocity field in the ninth embodiment of the present invention. The scanning center direction of the transmission light of the light wave radar apparatus is moved to the vicinity of the observation space (step 1901). Next, the initial value of the cone angle of the cone scan and the upper limit of the wind speed residual are set (step 1902). Based on this condition, the light wave radar device performs conical scanning of the transmitted light (step 1903).

The light wave radar apparatus calculates the line-of-sight direction wind velocity V _mi (step 1904), and further acquires the rotation angle γ _i of the cone scanning (step 1905). As the rotation angle γ _i of this conical scanning, first, the initial value set in step 1902 is used. Next, the light wave radar apparatus calculates a wind speed vector [u] based on the line-of-sight direction wind speed V _mi and the rotation angle γ _i of the cone scanning (step 1906). Further, the light wave radar apparatus calculates a residual between each gaze direction wind speed measurement value and the estimated gaze direction wind speed calculated from the wind speed vector (step 1907).

  Next, the lightwave radar apparatus determines whether or not the calculated residual is equal to or less than the upper limit value set in advance in Step 1903 (Step 1908). If it is less than or equal to the upper limit value, the light wave radar apparatus increases the rotation angle of the conical scanning by a predetermined amount (step 1909), and then repeats steps 1904 to 2308. When the calculated residual becomes larger than the upper limit value, the rotation angle of the conical scanning is set to the current value (step 1910), and the measurement process is ended.

  According to the ninth embodiment, it is possible to calculate the maximum cone scanning angle such that the residual between each gaze direction wind speed measurement value and the estimated gaze direction wind speed is equal to or less than a predetermined upper limit value, and uniform wind speed The maximum observation space that the field can assume can be set.

  Furthermore, by performing such calculation of the cone scanning angle before measuring wind conditions or for each scan center direction, it is possible to automatically set an observation space where the wind field is uniform, which may vary depending on topography or weather conditions. The effect is that the maximum space where the generated wind velocity field is uniform can be set as the observation space.

  Further, the threshold processing described in the second embodiment may be used in combination with the calculation of the Doppler speed in step S2004 in the flowchart of FIG. As a result, even when there is an optical path shield such as a building or a tree in the observation space to be evaluated for the uniformity of the wind velocity field, the wind velocity in the line of sight can be accurately measured, and the accuracy of the residual calculated in step S2007 can be increased. There is an effect that can be improved.

  Note that the maximum cone scanning angle at which the wind velocity field calculated in the ninth embodiment is uniform is used not only for the cone angle at the time of cone scanning but also for setting the scanning opening angle at the time of linear scanning. it can.

It is a block diagram of the light wave radar apparatus in Embodiment 1 of this invention. It is explanatory drawing of the wind condition measuring method by the light wave radar apparatus in Embodiment 1 of this invention. It is explanatory drawing of the wind speed vector calculation method in Embodiment 1 of this invention. It is a flowchart which shows the measurement process of the wind speed wind direction and wind condition of Embodiment 1 of this invention. It is a flowchart of the threshold value process based on the signal to noise ratio (SNR) of the received signal in Embodiment 2 of this invention. It is a figure which shows the structure for performing the wind condition examination of the wind power generation equipment in Embodiment 3 of this invention. It is a flowchart which shows the measurement process of the predetermined wind speed component in Embodiment 4 of this invention. It is a figure which shows the example of the lift distribution which generate | occur | produces in a windmill blade when a wind speed field inputs into a horizontal type windmill blade. It is a figure which shows the structure for performing the wind condition detailed examination of the wind power generation equipment in Embodiment 6 of this invention. It is explanatory drawing of the wind speed vector calculation method in Embodiment 6 of this invention. It is a flowchart which shows the measurement process of the wind speed wind direction and wind state of Embodiment 6 of this invention. It is a figure which shows the structure for performing the wind condition examination of the wind power generation equipment in Embodiment 7 of this invention. It is explanatory drawing of the wind speed vector calculation method in Embodiment 7 of this invention. It is a flowchart which shows the measurement process of the wind speed wind direction and wind state of Embodiment 7 of this invention. It is explanatory drawing of the scanning method of the transmitted light by the wedge prism in Embodiment 8 of this invention. It is explanatory drawing of the spatial scanning in Embodiment 8 of this invention. It is a figure which shows the locus | trajectory of the scanning azimuth | direction by the cone scanning of deflection angle 2 (alpha) cos (gamma) ₀ in Embodiment 8 of this invention. It is explanatory drawing regarding the locus | trajectory of the cone scanning in Embodiment 8 of this invention. It is the figure which showed the time waveform of the scanning angle in Embodiment 8 of this invention. It is a flowchart which shows the setting process of the observation space which can ensure the uniformity of the wind speed field in Embodiment 9 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 202, 302, 402 Light wave radar apparatus, 11 Light source part, 12 Optical transmission / reception part, 13 Scanning drive part, 14 Received signal generation part, 15 Wind speed vector calculation part, 202, 302, 402 Light wave radar apparatus, 502 Scanning mechanism part , 504, 504a, 504b Wedge prism.

Claims (12)

A light source unit that generates transmission light;
An optical transmission / reception unit that emits the generated transmission light into the atmosphere, collects scattered light from the atmosphere, and extracts it as reception light;
A scan driver that scans the optical path of the transmission light emitted from the optical transceiver in a preset direction;
A received signal generation unit that photoelectrically converts the extracted received light to generate a received signal;
The received signal is frequency-converted to detect a line-of-sight wind speed value, and an elevation angle and an azimuth angle corresponding to the line-of-sight wind speed value are read from the scanning drive unit, and the plurality of line-of-sight wind speed values detected correspond to A light wave radar apparatus comprising: a wind speed vector calculating unit that calculates a wind speed vector from an elevation angle and the azimuth angle;
The scanning drive unit calculates a scanning angle according to the distance so as to scan a plurality of points in the observation space that are separated from the scanning center by a predetermined value based on the distance to the observation space, and the calculated scanning Scanning the optical path of the transmitted light based on the angle;
The wind speed vector calculation unit calculates respective wind speed vectors corresponding to the directions of the plurality of points of the scanned transmission light, and combines the plurality of wind speed vectors to calculate the wind direction wind speed in the observation space. A light wave radar device characterized by the above. The light wave radar device according to claim 1,
The scanning drive unit sequentially moves in the scanning center direction with respect to a plurality of observation spaces having different directions, and measures wind conditions from respective wind directions and wind speeds calculated with respect to the plurality of observation spaces. A lightwave radar device. In the light wave radar device according to claim 1 or 2,
The drive scanning unit calculates a cone scanning angle according to a distance to the observation space so as to perform a cone scan in the observation space with a predetermined equal radius from a scanning center, and based on the calculated cone scanning angle An optical wave radar device, wherein the optical path of the transmission light is conically scanned. In the light wave radar device according to claim 3,
The wind speed vector calculation unit is configured to obtain an observation space based on each wind speed vector calculated corresponding to the direction of the plurality of points of the scanned transmission light and the known wind direction value in the direction of the plurality of points. A light wave radar device characterized by calculating a wind speed component in a specific direction in the interior and obtaining a wind speed component distribution in the specific direction in the observation space. The light wave radar device according to claim 4,
The wind speed vector calculation unit includes a storage unit in which data of a cone scanning angle associated with a wind speed component is accumulated, and the calculated cone scanning angle data corresponding to the wind velocity component in the specific direction is stored from the storage unit. A light wave radar device that extracts and performs conical scanning to recalculate the wind speed component. In the light wave radar device according to claim 3,
The wind velocity vector calculation unit assumes a case where a horizontal wind power generation facility is installed in a specific observation space, and matches a scanning center direction with a rotation center of a blade provided in the horizontal wind power generation facility, A light wave radar device, wherein a plurality of cone scanning angles are set within a predetermined range with respect to a rotation radius of the blade, and respective wind directions and wind speeds at the plurality of cone scanning angles are calculated. The light wave radar device according to claim 4,
The wind velocity vector calculation unit assumes a case where a horizontal wind power generation facility is installed in a specific observation space, and matches a scanning center direction with a rotation center of a blade provided in the horizontal wind power generation facility, A plurality of cone scanning angles are set within a predetermined range with respect to the rotation radius of the blade, and a wind velocity component distribution in the specific direction is obtained for each of the plurality of cone scanning angles. Radar device. In the light wave radar device according to claim 1 or 2,
The drive scanning unit calculates a scanning angle according to the distance to the observation space so as to linearly scan two points that are at a predetermined equal distance from the scanning center across the scanning center, and the calculated scanning angle An optical wave radar device characterized in that the optical path of the transmission light is linearly scanned based on. The lightwave radar device according to claim 8, wherein
The drive scanning unit scans with respect to the rotation center of a blade provided in the horizontal wind power generation facility, assuming that the horizontal wind power generation facility is installed in a specific observation space where the wind velocity field can be regarded as uniform. When performing a linear scan with the center directions coincident and sandwiching the rotation center of the blade, a plurality of scan angles are set within a predetermined range with respect to the rotation radius of the blade, and A light wave radar device that calculates each wind direction and wind speed. The light wave radar device according to any one of claims 3 to 9,
A scanning mechanism that deflects the transmission light by rotating the prisms having two wedge shapes installed independently on the optical path of the transmission light;
The drive scanning unit controls the initial phase, the rotation speed, and the rotation direction of each of the prisms of the scanning mechanism unit to cause the transmitted light to perform conical scanning or linear scanning. In the lightwave radar device according to any one of claims 1 to 10,
The wind speed vector calculation unit measures a signal-to-noise ratio of the received signal, and when the measured value of the signal-to-noise ratio is within a preset allowable range of the signal-to-noise ratio, the received signal is Adopting and calculating the wind speed vector, and when the measured signal-to-noise ratio value is outside the preset allowable range of the signal-to-noise ratio, the received signal is not adopted and the received signal generator An optical wave radar device that receives a new reception signal and measures a signal-to-noise ratio of the new reception signal again. The light wave radar device according to claim 1,
The wind speed vector calculation unit obtains a standard deviation of a residual between each gaze direction wind speed value obtained by scanning transmission light at a certain cone scanning angle and a result of calculating each gaze direction wind speed component from the wind speed vector. In each observation space, each standard deviation corresponding to a plurality of predetermined scanning angles is calculated, and each of the calculated standard deviations is within a preset allowable standard deviation. A light wave radar device, wherein a maximum scanning angle is obtained from the inside, and the wind direction and wind speed are calculated by employing the maximum scanning angle.

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