JP2005312163A - Power generation control device and power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an influence on a frequency and a voltage of an electric power system due to an output fluctuation of a solar cell without providing a power storage device.
In a power generation system 10 including a solar cell 2, a grid-connected inverter 3 that converts the output of the solar cell and outputs the converted power to a power system 4, and a plurality of power generation devices 5 connected to the power system 4. The power generation control unit 20 predicts the output of the solar cell after a predetermined time based on a plurality of images taken by the imaging camera 21 and the power system based on the predicted change in output. In order to prevent the total of the electric power output from the solar cell and the power generation device from decreasing, an activation means 24 for controlling activation / stop of the plurality of power generation devices is included.
[Selection] Figure 1

Description

  The present invention relates to a power generation control device and a power generation system, and more specifically, a power generation control device that controls a plurality of power generation devices connected to a power system to which a photovoltaic power generation system is connected, and power generation including the power generation control device It is about the system.

  In recent years, problems such as global warming due to carbon dioxide emissions associated with the use of fossil fuels, accidents at nuclear power plants and radioactive contamination due to radioactive waste have become serious, and interest in the global environment and energy has increased. Under these circumstances, distributed power sources connected to commercial AC power systems (hereinafter also simply referred to as “power systems”) such as photovoltaic power generation systems that use sunlight as an inexhaustible and clean energy source have become widespread. ing.

  Current solar power generation systems are mainly installed on the roofs of ordinary houses. FIG. 8 is a block diagram showing a configuration of a general photovoltaic power generation system. As shown in the figure, in the photovoltaic power generation system 1, the DC power generated by the solar cell 2 is converted into AC power by the grid interconnection inverter 3. The output from the grid-connected inverter 3 to the power system 4 varies according to the variation in the output of the solar cell.

  The power system 4 is normally connected to a power generation device 5 including a plurality of generators (5a, 5b). The control means 50 controls the operation (starting and stopping) of the generator (power generation device 5) so that the voltage and frequency of the power system 4 are stabilized and based on a predetermined supply and demand plan. This supply and demand plan is generally planned in consideration of past fluctuations in the load 6.

  As described above, the power generation system 10 includes the power system 4, the control device 50, and the solar power generation system 1. In remote islands and mountainous areas, a plurality of diesel generators are used as the power generation device 5 to supply power to the power system 4.

  Generally, stabilization of frequency and voltage is important in the power system 4. With respect to fluctuations in power consumption at the load 6, the operation of the power generator 5 is controlled based on the above supply and demand plan so that the frequency and voltage do not fluctuate.

  However, in a relatively small-scale power system using a plurality of diesel generators as the power generation device 5, the output ratio of the photovoltaic power generation system 1 may be relatively high. The influence that the output fluctuation of the photovoltaic power generation system 1 has on the frequency and voltage of the power system 4 increases.

  Many control methods and systems for reducing the influence of such output fluctuations of the photovoltaic power generation system have been proposed. For example, in Japanese Patent Publication No. 2-61227 (Patent Document 1), when a solar cell is connected to a grid, the output of the solar cell is prevented so that a sudden output fluctuation of the solar cell does not affect the grid. Is temporarily stored in a power storage device such as a battery, the output or solar radiation intensity of the solar cell is detected, and the output of the grid interconnection inverter is controlled so as to obtain a smoothed value.

  Japanese Patent Application Laid-Open No. 63-186538 (Patent Document 2) provides a system stabilizing device including a battery (power storage device) and a bidirectional converter in an electric power system, and stabilizes the system when a load fluctuation occurs. A method for adjusting the output from the device is described.

That is, in the methods described in these documents, when the output variation of the photovoltaic power generation system affects the power system when the photovoltaic power generation system is connected, the output of the photovoltaic power generation system is less than the threshold value. When the voltage drops, insufficient power is supplied from the system stabilizing device, and when the output exceeds the threshold value, load leveling is performed to be absorbed by the system stabilizing device.
Japanese Examined Patent Publication No. 2-61227 JP-A 63-186538

  However, in the power generation systems described in Patent Document 1 and Patent Document 2, a power storage device having a capacity corresponding to the power generation capacity of the solar battery is required. As the capacity increases, the power storage device becomes larger and more expensive, which greatly affects the cost and size of the entire power generation system.

  Therefore, the inventors of the present application have studied in detail the case where there is no power storage device in the power generation system having the above configuration, and as a result, it has been found that the following problems may occur. Hereinafter, it demonstrates using drawing.

  FIG. 9 is a time chart for explaining the start timing of the diesel generator. In each of (a) to (c), the horizontal axis represents time. (A) is a time chart which shows the output of the two diesel generators 5a and 5b, the output of the solar cell 2, and the electric power supplied to the load 6. FIG. (B) is a time chart showing the starting or stopping state of the diesel generator (5b) that is initially in a stopped state, and (c) is the state of the command (starting or stopping) from the control means 50 to the power generator 5b. It is a time chart which shows (stop).

  In FIG. 9, at the first time indicated by t0, one diesel generator (5b) is in a stopped state and only the other diesel generator (5a) is activated. The control means 50 outputs a stop command to the diesel generator (5b) in a stopped state.

  Next, at time t3, as shown to (a), the output of the solar cell 2 begins to fall, and the output from the diesel generator (5a) in a starting state increases.

  At time t4, the output of the diesel generator (5a) becomes high and approaches the equipment capacity, so that the control means 50 issues a start command to the diesel generator (5b) in a stopped state, as shown in FIG. Output.

  At time t5, the output of the diesel generator (5a) reaches the equipment capacity, and after the time t5, it becomes impossible to compensate for the decrease in the output of the solar cell 2, so that the power supplied to the load decreases. As a result, the voltage and frequency of the power system 4 may fluctuate and possibly deviate from a predetermined power quality range.

  At time t6 after elapse of time Tsb required for starting the diesel generator (5b) that has received the start command at time t4, as shown in (b), the diesel generator (5b) that has been stopped is started, As shown in (a), the power supplied to the load is gradually increased by the outputs from the generators 5a and 5b and recovered to the original value.

  As described above, since a certain amount of time (about several tens of seconds to about 5 minutes) is required to start the diesel generator, if the output of the solar battery 2 is rapidly reduced, the output capacity from the diesel generator during operation is not sufficient. There is a risk that the frequency and voltage of the power system will decrease.

  In a normal power system, for example, a hydroelectric generator is sometimes used for power adjustment, but the hydroelectric generator also takes time (about 2 to 5 minutes) to start. Therefore, when a photovoltaic power generation system becomes widespread in a normal power system and the power generation capacity increases, the output fluctuation of the photovoltaic power generation system is similar to the case of a relatively small scale by a diesel generator. It greatly affects the voltage.

  This is the same even when using a power generation device that uses a long time to start, such as a power generation device using an internal combustion engine other than a diesel generator as a power generation device, or a power generation device that converts power into AC power using a fuel cell as an energy source. is there.

  This invention is made | formed in view of the above situations, and it aims at reducing the influence on the frequency and voltage of an electric power system by the output fluctuation of a solar cell, without providing an electrical storage apparatus.

A power generation control device as one aspect of the present invention that achieves the above object includes a solar cell, a grid-connected inverter that converts the output of the solar cell and outputs the converted power to a power system, and a plurality of power sources connected to the power system. A power generation control device for controlling the plurality of power generation devices in a power generation system including:
Predicting means for predicting the output of the solar cell after a predetermined time;
Starting means for controlling a starting state of the plurality of power generation devices based on a predicted change in output so that a total of power output from the solar cell and the power generation device does not decrease in the power system; I have.

  In this manner, in a power generation system including a solar cell, a grid-connected inverter that converts the output of the solar cell and outputs the converted power to the power system, and a plurality of power generation devices connected to the power system, a predetermined solar cell Start up multiple generators so that the total power output from the solar cells and generators to the grid is not reduced based on the predicted change in output when the output after time is expected to decline / Stop is controlled.

  Therefore, even when the output of the solar cell is reduced, the amount of power supplied to the power system is compensated by the power supplied from the power generation device, so that the influence on the frequency and voltage of the power system due to the output fluctuation of the solar cell is reduced. The Further, since the power storage device is unnecessary, the entire power generation system can be reduced in size and cost.

  The predetermined time is longer than the time required for the power generation device to start, and the activation means determines that the amount of decrease in the output of the solar cell predicted after the predetermined time cannot be compensated for by the power generation device already activated. In consideration of the time required for starting, it is preferable to start the power generation device in a stopped state.

  The image capturing device further includes at least an image capturing unit that captures images of the surroundings of the sun at predetermined time intervals, and the predicting unit relates to a cloud having a predetermined size or more around the sun based on a plurality of images captured by the image capturing unit. It may be configured to acquire information. Here, the information regarding the cloud includes the position of the cloud, the moving direction, and the moving speed.

  As the imaging means, any of a color imaging camera, a monochrome imaging camera, a color imaging camera with a filter, and a monochrome imaging camera with a filter can be used.

  The prediction means may include solar information acquisition means for acquiring information on the position, moving direction, and moving speed of the sun.

  Further, the prediction means may be configured to acquire information relating to a cloud having a predetermined size or more around the sun based on outputs of a plurality of light intensity measurement means installed at a distance. .

Moreover, the electric power system as another aspect of this invention which achieves the said objective is a solar cell,
A grid-connected inverter that converts the output of the solar cell and outputs it to the power system;
A plurality of power generators connected to the power system;
A power generation control device for controlling the plurality of power generation devices,
Predicting means for predicting the output of the solar cell after a predetermined time;
Starting means for controlling a starting state of the plurality of power generation devices based on a predicted change in output so that a total of power output from the solar cell and the power generation device does not decrease in the power system; Including power generation control means.

  Furthermore, the object of the present invention is also achieved by a power control method of a power generation system corresponding to the power control device described above, a computer program that causes the computer device to execute the method, and a storage medium that stores the program.

  According to the present invention, even when the output of the solar cell is reduced, the amount of power supplied to the power system is compensated by the power supplied from the power generation device. Impact is reduced. Further, since the power storage device is unnecessary, the entire power generation system can be reduced in size and cost.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the components described in the following embodiments are merely examples, and are not intended to limit the scope of the present invention only to them.

<Basic configuration>
FIG. 1 is a block diagram showing a basic configuration example of a power generation system according to the present invention.

  A power generation system 10 in FIG. 1 includes a solar power generation system 1, a power system 4, and a power generation control device 20.

  The solar power generation system 1 includes a grid-connected inverter 3 that converts the output from the solar cell 2 into power and outputs it to the power grid 4. The power system 4 includes a power generation device including a plurality of power generation devices (5a and 5b), and a load 6 to which power is supplied from the solar power generation system 1 and the power generation device 5.

  The solar power generation system 1 is not particularly limited. However, when the ratio of the rated output capacity of the photovoltaic power generation system 1 to the rated output of the power generation device 5 (the total output of the power generation devices 5a and 5b) is high, the influence of the photovoltaic power generation system 1 on the power system 4 increases. The effect of the present invention is increased, which is preferable. For example, when the rated output capacity of the photovoltaic power generation system 1 is 5% or more of the rated output of the power generation device 5, the effect of the present invention is increased, which is preferable.

  There is no restriction | limiting in particular in the kind of solar cell 2, an installation form, etc. For example, as the power generation layer of the solar cell 2, various materials such as single crystal silicon, polycrystalline silicon, microcrystalline silicon, amorphous silicon, CIS, and dye sensitization can be used, and a combination thereof may be used. . A stacked solar cell in which a plurality of power generation layers of the same or different materials are stacked can also be used. Moreover, as the installation form of the solar cell 2, various forms such as a roof material integrated type, a roof frame installation type, a ground frame installation type, a wall material integrated type, and a double-sided power generation installation type can be used.

  The grid interconnection inverter 3 is not particularly limited as long as the electrical system, voltage, frequency, etc. of the power system 4 are compatible. Various circuit methods include a three-phase bridge circuit, a single-phase bridge circuit, a combination of a boost converter and a single-phase bridge circuit, a circuit method in which a sine wave modulation high-frequency inverter output is full-wave rectified and turned back into a sine wave Can be used. Further, the input and output of the grid interconnection inverter 3 may be insulated or non-insulated.

  The power system 4 is generally one that transmits and distributes the generated power of the power generation device 5 and performs voltage conversion and electric system conversion as appropriate through a transformer, but there is no particular limitation in the present invention. In addition, the present invention can be applied to not only a normally used AC system but also a DC system.

  There are no particular restrictions on the electrical system, voltage, frequency, etc., as the power generator 5, and various devices can be used. Normally, a three-phase three-wire system is used, but a single-phase two-wire system is used when the power generation capacity is small. The power generation device 5 includes a plurality of power generation devices (5a and 5b), of which 5a is activated first. There is no restriction | limiting in particular in the electric power generating apparatus 5a started initially. The power generation device 5b that is activated from the stopped state when the power to be supplied from the power generation device 5 increases requires time Ts until it is activated in response to the activation command from the stopped state, and the activation time Ts is determined in advance. What is understood is necessary in the present invention.

  As a specific example of the power generation device 5, for example, a power generation device using an internal combustion engine such as a diesel generator whose start time Ts is about several tens of seconds to about 5 minutes, a fuel cell whose start time Ts is about several tens of seconds to about 1 hour There is a power generation device that supplies power by converting the power as an energy source, or a power generation device using a hydroelectric generator with a startup time Ts of about 2 to 5 minutes.

  In FIG. 1, the number of power generation devices in the power generation device 5 is two, but may be three or more. The present invention can be applied as long as a part of the plurality of generators can be started and stopped according to the power to be supplied from the power generation device 5. The plurality of power generators 5 are not necessarily the same type, and may be a combination of different types.

  In addition, the power generation capacity of the power generation device 5 is not particularly limited. In the case where the power generation device 5 has a relatively small capacity (several tens of MW or less) or the power generation of the solar power generation system 1 accounts for 5% or more of the installed capacity of the power generation device 5, the solar power generation system The present invention is suitable because it is easily affected by output fluctuations. In particular, an isolated power system mainly operated by a diesel generator has a relatively small power generation capacity, so the operation (start / stop) of the diesel generator is easily affected by fluctuations in the output of the power generation system. The present invention is suitable for predicting the battery output and starting the power generation device 5b in advance to stabilize the power system.

  The power generation control device 20 is an example of a power generation control device according to the present invention. The imaging camera 21 captures an image of the sky above the solar cell 2, and the prediction of the solar cell 2 based on a plurality of images captured by the imaging camera 21. Output means for outputting output information, and a start means 24 for controlling the operation of the power generation device 5 according to the output prediction information of the solar cell by the prediction means 23. For example, the starter 24 is configured such that the power generation device 5b is stopped and the output of the solar cell decreases within a predetermined time T1 longer than the start time Ts of the power generation device 5b, and the power generation being started up with respect to the power consumption of the load 6 When it is determined that the power generation capacity is insufficient with only the device 5a, the power generation device 5b is activated.

  The imaging camera 21 is not particularly limited as long as it can capture at least a cloud image around the sun. For example, various devices such as a color CCD camera, a monochrome CCD camera, a color CMOS camera, a monochrome CCD camera, and a logarithmic conversion type CMOS camera can be used. A CMOS camera is preferable because it does not cause smear or blooming, which is a problem with a CCD camera when the sun is in the shooting screen, and can accurately capture a cloud image. Further, the logarithmic conversion type CMOS camera is preferable because it has a wider dynamic range than a normal linear output type camera and can accurately photograph clouds in the vicinity of the sun with extremely high brightness. Further, it is preferable that a CCD camera of the frame interline transfer type is free from smear and can accurately capture a cloud image. In addition, for example, by using a filter such as a red filter, a yellow filter, or an infrared transmission filter, the contrast between the clouds and the sky can be enhanced, and a clear image of the clouds can be obtained. It is preferable in accurately calculating the moving speed of the cloud.

  As the installation method of the imaging camera 21, various installation methods such as fixed installation and installation on a tracking base that automatically tracks the sun can be applied. In the fixed installation, the sun moves through a wide angle of about 180 degrees as viewed from the imaging camera 21, so that most of the sky, at least a range where sunlight enters the solar cell 2 can be photographed, such as a fisheye lens. It is desirable to be configured to shoot using a wide-angle lens.

  The predicting means 23 may be anything that predicts the output of the solar cell 2 from the state of clouds or the sun based on a plurality of images input from the photographing camera 21. The calculation speed is not particularly limited as long as the processing time required for output prediction is about several seconds to 5 minutes or less. For example, it can be configured by a PC (personal computer), a workstation, or an embedded computer.

  Information used by the prediction means 23 for output prediction includes information about clouds and information about the sun. Examples of information about clouds include, for example, a cloud position Pc, a cloud moving direction Dc, a cloud moving speed Vc, Use the size of the clouds. Moreover, as the information regarding the sun, for example, the position Ps of the sun, the moving direction Ds of the sun, the moving speed Vs of the sun, and the like may be used. The information about the sun may be calculated from the image of the photographing camera 21 by image processing or the like, or may be calculated from the latitude, longitude, date and time of the installation location.

  As a method of predicting the output of the solar cell 2, for example, a cloud position Pc, a cloud moving direction Dc, a cloud moving speed Vc, a sun position Ps, and a sun moving direction Ds with respect to a cloud of a predetermined size or larger. There is a method of predicting the timing at which the positions of the sun and the clouds overlap from the moving speed Vs of the sun. Moreover, if the amount of solar radiation is predicted by predicting the amount of solar radiation from the cloud concentration (or the degree of solar radiation transmission), the surroundings of the sun, and the conditions of a wider range of clouds, the output of the solar cell 2 is further increased. Precise prediction is preferable.

  The activation unit 24 is not particularly limited as long as it can output at least a signal instructing activation to the power generation device 5 based on the output prediction information of the solar cell 2 received from the prediction unit 23. For example, it can be configured by a PC, a workstation, or an embedded computer. Further, the prediction means 23 can be used in part or in whole, and in this case, there is an advantage that the size and cost can be reduced.

  The activation means 24 instructs the activation of the power generation device 5b when it is determined that the output of the solar cell 2 is reduced within a predetermined time T1b longer than the time Tsb required for activation of the power generation device 5b that is stopped among the activation power generation devices 5 Then, the power generation device 5b is activated. Further, when it is determined from the power generation capacity of the currently operating power generation device 5a and the current generated power that the output of the solar cell 2 is reduced within the predetermined time T1b and the power generation capability of the power generation device 5a is insufficient, the power generation device It is preferable to instruct activation of 5b to activate the power generation device 5b. Furthermore, with respect to the predicted load power based on the supply and demand plan that takes into account past load fluctuations, it is determined that the output of the solar cell 2 decreases within the predetermined time T1b and the power generation capacity of the power generation device 5a in operation is insufficient. In this case, it is preferable to instruct activation of the power generation device 5b and activate the power generation device 5b. Further, it may be configured to detect how much current load is present and to monitor necessary power, and in this way, more accurate control can be performed. Moreover, you may have the function to estimate the fluctuation | variation of load based on a supply-and-demand plan, and to judge whether power generation capability is insufficient.

  The activation time Ts varies depending on the power generator 5, but the predetermined time T1 needs to be set longer (longer) than the activation time Ts. Generally, in a diesel generator or the like, the power generation efficiency is high near the rated output, and the power generation efficiency decreases at a low output. Therefore, if the predetermined time T1 is excessively increased, the output of each power generation device in the power generation device 5 is long and low. The operation is performed for a period of time, and the power generation efficiency of the power generation device 5 decreases and the operation cost increases. Therefore, the length of the predetermined time T1 may be appropriately set in consideration of the accuracy of output prediction at the output prediction time. For example, the predetermined time T1 may be set to a value that is approximately 1 to 10 minutes greater than the activation time Ts. Further, the predetermined time T1 may be set to a value of about 1.1 to 3 times the activation time Ts.

  In addition, a part or all of the connection between the imaging camera 21 and the prediction unit 23, the connection between the prediction unit 23 and the activation unit 24, and the connection between the activation unit 24 and the power generation device 5 may be appropriately connected via the communication unit. It can also be configured, and the degree of freedom of installation and the flexibility of the configuration are improved. As the communication means, for example, wired communication or wireless communication, telephone line communication, Internet / intranet communication, dedicated line communication, satellite line communication, or a combination thereof can be used as appropriate. It is preferable to have a plurality of communication means of the same type or different types because the communication reliability is improved.

  When there are a plurality of photovoltaic power generation systems 1, an imaging camera and a prediction unit 23 are provided for each, and the output predicted value of each photovoltaic power generation system 1 is input to one activation unit 24. However, based on the total value of the predicted output values, the power generation device 5b is stopped, the output of the solar cell decreases within a predetermined time T1 longer than the start time Ts of the power generation device 5b, and the power consumption of the load 6 is reduced. The power generation device 5b may be activated when it is determined that the power generation capability is insufficient with only the power generation device 5a in operation.

<First Embodiment>
The power generation system according to the present invention described above will be described below by taking a specific embodiment as an example.

  The specific configuration of the first embodiment of the present invention is the same as the basic configuration shown in FIG. 1, but in this embodiment, a fixed color CCD camera is used as the imaging camera 21, and a power generation device 5 uses two diesel generators.

  A plurality of images photographed at a predetermined time interval by a color CCD camera are input to the predicting means 23, and cloud information is calculated using image processing. That is, the cloud cloud position Pc is recognized based on the brightness and color of the image, a place having a high correlation is searched for from the plurality of images, and the cloud moving direction Dc and the cloud moving speed Vc are determined from the difference. Ask for.

  FIG. 2 is a diagram illustrating an example of a plurality of images captured by a color CCD camera. Assume that the three images shown in (a) to (c) were taken at times ta, tb, and tc, respectively.

  Image processing is performed on the image (a) photographed at time ta, and the outline of the cloud 202 whose size in the image is equal to or larger than a predetermined size (for example, 1/10 or more of the size of the sun in the image) is extracted. Then, it is recognized that the cloud 202 is on the right side at some distance from the sun 201. Next, when the same processing is performed on the image (b) taken at time tb, it is recognized that the cloud 202 is on the right side in the vicinity of the sun 201. Then, by searching for a part having a high correlation between the cloud image parts (a) and (b), it can be seen that the moving direction Dc of the cloud 202 is the left direction in FIG. 2 from time ta to time tb. Further, the moving speed Vc between time ta and time tb can be calculated from the difference between the cloud position in (a) and the cloud position in (b). From the information about the cloud thus obtained, that is, from the position Pc, the moving direction Dc, and the moving speed Vc, at a time tc after a lapse of a certain time from the time tb, the position of the cloud is as shown in (c). Can be predicted.

  Further, the position Ps, the moving direction Ds, and the moving speed Vs, which are information related to the sun, can be easily calculated from the information on the latitude, longitude, and date / time of the installation location of the solar cell 2 (color CCD camera) set in advance. In this case, the position of the sun can be calculated even when the sun is covered with a very black (dark) cloud. The calculated azimuth and elevation angle of the sun needs to correspond to the position on the image taken by the color CCD camera, but the installation angle (azimuth, elevation angle, rotation angle) of the color CCD camera and the image of the color CCD camera are required. Since the angular characteristics are known in advance, they can be associated with each other. At the same time, the high-brightness portion is determined as the position of the sun from the image of the color CCD camera, and the solar cell information and / or cloud information is corrected so as to be the same position as the calculated sun position. Thereby, the error of the information of latitude, longitude, and date and the error of the installation angle of the color CCD camera can be corrected, and the accuracy of output prediction of the solar cell 2 is improved.

  Next, operations of the prediction unit 23 and the activation unit 24 will be described with reference to the flowchart of FIG. FIG. 3 is an operation flowchart regarding start-up of the diesel generator, which is executed when the solar power generation system 1 is in operation.

  First, in step S01, the cloud position Pc, the cloud moving direction Dc, the cloud moving speed Vc, the sun position Ps, and the sun are based on the plurality of images taken by the color CCD camera as described above. The moving direction Ds of the sun and the moving speed Vs of the sun are calculated.

  Next, in step S02, the time at which the sun is clouded is calculated from the position of the sun and the movement of the cloud based on the calculated cloud and sun information, and at least a part of the sun is hidden in the cloud within a predetermined time T1. It is determined whether or not. If it is determined that the cloud is hidden, the process proceeds to step S03. If it is determined that the cloud is not hidden, the process ends without executing step S03.

  If it is determined that it is hidden by the cloud, in step S03, the required amount of power generated by the diesel generator is calculated, and if the power generation capacity of the activated diesel generator (5a) is insufficient, the other diesel generator 5b is started. Output a command to In this case, in this embodiment, since the starting time Tsb of the diesel generator 5b is 5 minutes, the predetermined time T1b is set to 10 minutes.

  By repeating the above operation every time a new image is taken with the color CCD camera, even if at least a part of the sun is hidden behind the clouds and the output of the solar cell decreases, the power supplied to the load is insufficient. Can be prevented.

  FIG. 5 is a time chart showing the state of signals relating to the diesel generator in the present embodiment. The horizontal axis represents time, and (a) shows the diesel generators 5 a and 5 b, the output of the solar cell 2, and the power consumption of the load 6. (B) shows the starting or stopping state of the diesel generator (5b) that is initially in a stopped state. (C) has shown the state (starting or a stop) of the command signal with respect to the diesel generator 5b from the starting means 24. FIG.

  In FIG. 5, at the first time t0, one diesel generator (5b) is in a stopped state, and only the other diesel generator (5a) is activated. In the starting means 24, the stop is instruct | indicated with respect to the diesel generator (5b) in a stop state.

  Next, at time t1, as shown in (c), a decrease in the output of the solar cell 2 after a predetermined time T1b is predicted based on the operation flowchart shown in FIG. 3, and the diesel generator (5b) in the stopped state is stopped. In response to this, an activation signal is transmitted.

  At time t2 after elapse of the activation time T1b of the diesel generator (5b) in the stopped state from time t1, as shown in (b), the diesel generator (5b) in the stopped state is activated. Accordingly, the power output from the power generator 5 is a value obtained by adding the sum of the output power of the diesel generator 5a and the output power of the diesel generator 5b to the output power of the solar battery.

  Thereafter, after time t3, as shown in (a), the output of the solar cell 2 decreases, but since the diesel generator (5b) that has been stopped in advance has already been started, the output of the solar cell decreases. Minutes can be supplemented by increasing the output of the two diesel generators (5a and 5b), and the power supplied from the power generator 5 to the load does not decrease. Thereby, the influence on the frequency and voltage of the power supplied to the load can be suppressed.

  In the example of FIG. 5, the case where the output fall of the solar cell 2 generate | occur | produced after predetermined time T1b as shown by the prediction means is shown. Actually, the output of the solar cell 2 may decrease somewhat earlier than predicted, but the predetermined time T1b is set longer than the start-up time Tsb in consideration of a prediction error regarding the time when the output of the solar cell 2 decreases. If it sets, since the diesel generator (5b) which was a stop state before the output of the solar cell 2 falls can be started previously, stabilization of an electric power system can be aimed at.

  Further, in the present embodiment, when the output of the solar cell 2 increases (the sun appears from the clouds), the diesel generator is stopped according to the output power. However, referring to the flowchart shown in FIG. The operation in this case will be described.

  First, in step S11, similarly to step S01 of FIG. 3 described above, the cloud position Pc, the cloud moving direction Dc, and the cloud moving speed are based on a plurality of images taken from the color CCD camera. Vc, the sun position Ps, the sun moving direction Ds, and the sun moving speed Vs are calculated.

  Next, in step S12, it is determined from the calculated cloud and sun information whether the sun is hidden behind the cloud after a predetermined time T1b. If it is determined that the cloud is not hidden after the predetermined time T1b, the process proceeds to step S13. If it is determined that the cloud is hidden behind the predetermined time T1b, the process is performed without executing step S13 and skip S14. Exit.

  When it is determined that the cloud is not hidden after the predetermined time T1, in step S13, the power generation requirement of the diesel generator is calculated, and whether the power generation requirement is within the power generation capacity of one diesel generator, That is, it is determined whether one diesel generator 5b of the two diesel generators that are currently activated may be stopped (whether or not there are surplus generators), and the power generation capacity of one diesel generator If it is within the range (remaining generators), the process proceeds to step S14, and if it is larger than the power generation capacity of one diesel generator, the process ends without executing step S14.

  In step S14, a stop signal is output to stop the one diesel generator (5b), and the diesel generator 5b is stopped.

  When a new image is taken with a color CCD camera, the above operation is repeated, so that if the sun appears from the clouds and the output of the solar cell increases, the remaining diesel generator should be stopped immediately. Can do.

  Thereby, when there is little electric power amount which should be generated with the electric power generating apparatus 5, a diesel generator can be used effectively by reducing the number of the diesel generators to start. In addition, the fuel consumption and the running cost of the power generation system can be reduced.

As described above, according to the present embodiment, the power system can be stabilized without a power storage device, so that the power generation system can be reduced in size and cost. In addition, since the standby power generation device 5b is activated only when it is necessary to predict the decrease / increase in the output of the solar cell 2, the power generation device 5 is more effective than those that always activate all the power generation devices 5. Therefore, the fuel consumption can be reduced and the running cost and the CO ₂ emission can be reduced.

<Second Embodiment>
Hereinafter, a second embodiment of the power generation system according to the present invention will be described. The second embodiment is also a power generation system similar to that of the first embodiment. In the following description, the description of the same parts as those of the first embodiment is omitted, and the characteristic parts of this embodiment are mainly described. explain.

  FIG. 6 is a block diagram showing a specific configuration of the second embodiment. The second embodiment differs from the first embodiment in that the imaging camera and the power generation device 5 are three diesel generators.

  In the first embodiment shown in FIG. 1, the imaging camera 21 is a color CCD camera. However, in this embodiment, the imaging camera 21 is a monochrome CCD camera, and a red filter is provided on the light receiving front surface of the monochrome CCD camera. 26. The power generation device 5 includes three diesel generators 5a, 5b, and 5c.

  In the monochrome CCD camera (imaging camera 21) provided with the red filter 26, the red filter 26 absorbs blue sky (light having a short wavelength), so that the contrast between the cloud and the sky increases, and information about the cloud ( The process of obtaining the cloud position Pc, the cloud moving direction Dc, and the cloud moving speed Vc) can be performed with high accuracy and ease.

  Moreover, the starting means 24 starts the three diesel generators in the electric power generating apparatus 5 in order of the diesel generator 5a, the diesel generator 5b, and the diesel generator 5c.

  When only one diesel generator 5a is activated in the power generator 5, the output of the solar cell 2 is output after the predetermined time T1b using the predetermined time T1b corresponding to the activation time Tsb of the diesel generator 5b. When it is predicted to decrease, a start command is output to the diesel generator 5b to start the diesel generator 5b.

  Further, when two diesel generators 5a and 5b of the power generator 5 are activated, the solar cell 2 is used after a predetermined time T1c using a predetermined time T1c corresponding to the activation time Tsc of the diesel generator 5c. When it is predicted that the output will decrease, a start command is output to the diesel generator 5c to start the diesel generator 5c.

  Furthermore, when only one diesel generator 5a is activated in the power generation device 5, it is predicted that the output of the solar cell 2 will decrease after the shorter predetermined time of the predetermined time T1b or the predetermined time T1c. In the case where it is determined that the power generation capacity of the two power generators 5 that have been activated is insufficient even when only the diesel generator 5b is activated, not only the diesel generator 5b but also the diesel generator 5c In response to this, a start command is output to start the diesel generators 5b and 5c.

  As described above, according to the present embodiment, when the number of diesel generators is three or more, it is necessary according to the required electric energy when the output of the solar cell 2 is predicted to decrease. By starting up a large number of diesel generators in advance, the power generation capacity of the power generation device 5 can be secured, and it becomes possible to compensate for the decrease in the output of the solar cell 2 by the output of the power generation device 5, thereby stabilizing the power system. Can be planned.

<Third Embodiment>
Hereinafter, a third embodiment of the power generation system according to the present invention will be described. The third embodiment is also a power generation system similar to the first and second embodiments, and in the following description, the description of the same parts as the first embodiment is omitted, and the characteristic parts of the present embodiment The explanation will be focused on.

  In the first embodiment, it is configured to predict a decrease / increase in the output of the solar cell 2 using a plurality of images taken at a predetermined interval by the imaging camera 21, but in the third embodiment, The light intensity measuring means 30 is arranged around the solar cell 2 at a distance, and the start-up of the generator in the power generator 5 is controlled based on the output of the light intensity measuring means.

  As the light intensity measuring means 30, a plurality of small area light intensity measuring solar cells 30a, 30b, 30c and 30d are used. An output signal from the light intensity measuring unit 30 is input to the predicting unit 23. Any output signal may be used as long as the light intensity incident on the solar cell 2 can be calculated, and the output current, output power, output voltage value or information of the light intensity measurement solar cell 30 can be used. It is preferable to use the value or information of the output current or output power that is approximately proportional to the intensity. In the present embodiment, the output current of the light intensity measurement solar cell 30 is used. However, since the distance between the prediction means 23 and the light intensity measurement solar cell 30 is long, a detection signal representing information related to the output current is transmitted.

  The prediction means 23 predicts a change in the output of the solar cell 2 based on the outputs (detection signals) from the small area light intensity measurement solar cells 30a to 30d. For example, among the small area light intensity measurement solar cells 30a to 30d arranged in the four directions around the solar cell 2 (east, west, south, and north), if there is a battery whose output decreases, it is determined that the cloud approaches and the output decreases in the future. To do. In addition, the approach direction of the cloud can be known according to which output of the small area light intensity measurement solar cell has decreased. In addition, the amount of change in the output of the solar cell 2 is predicted according to the amount of change in the output of the solar cell 30 for measuring light intensity.

  Further, in response to the prediction result by the predicting means 23, the starting means 24 determines that the power generation capacity of the currently activated diesel generator 5a is insufficient, as in the first embodiment. The machine 5b is activated in advance.

  Thereby, when the output of the solar cell 2 decreases, the power generation capacity of the power generation device 5 can be secured, and the decrease in the output of the solar cell 2 can be compensated by the output of the power generation device 5, and the power system 4 can be stabilized. I can plan.

  When the distance between the predicting unit 23 and the light intensity measuring solar cell 30 is relatively short, the output of the light intensity measuring solar cell 30 can be directly output to the predicting unit 23. In this way, There is an advantage that a communication device is not required in the solar cell 30 for measuring light intensity, and the configuration is simplified.

  In addition, if the number of small area light intensity measurement solar cells is increased, it becomes possible to obtain more accurate information on cloud movement and cloud moving speed. For example, you may arrange | position a small area light intensity measurement solar cell so that it may surround the circumference | surroundings of the solar cell 2 several times. In this case, for example, the time until the output of the small area light intensity measurement solar cell arranged on the outside decreases and the output of the small area light intensity measurement solar cell arranged on the inside decreases, and the output decreases. The approach speed of the cloud can be predicted from the distance between the small area light intensity measurement solar cell arranged outside and the small area light intensity measurement solar cell arranged inside where the output is reduced.

  Furthermore, if there is position information such as coordinates for each of the small area light intensity measurement solar cells, the approaching direction of the cloud that affects the output change of the solar cell 2 can be predicted more accurately, so that the prediction accuracy is further improved. I can do things.

  Furthermore, in the case where a plurality of power generation systems according to the present invention are installed in the vicinity, for example, if the positions where the solar cells of the power generation system scattered in the surroundings are clear, the solar cells If the output is regularly obtained through communication means (for example, the Internet), the solar cell of the surrounding solar power generation system can be used in place of the small area light intensity measurement solar cell 30 of the present embodiment. . In this way, it is not necessary to install the light intensity measurement solar cell 30 around the solar cell 2, so that there is an advantage that the system cost can be greatly reduced.

<Other embodiments>
The present invention is not limited to the above-described embodiment, and various modifications can be made within the spirit of the present invention.

  The present invention may be applied to a power generation system including a plurality of devices, or may be applied to a power generation control device of a power generation system including a single device.

  In the above embodiment, the plurality of power generators are all of the same type (diesel generator). However, the type of generator constituting the power generator is the scale of the power generation system or the environment in which it is installed. Can be the same or different. As the types of power generators that can be used, there are a fuel cell, a device using an internal combustion engine as a power generator, a hydroelectric generator, and the like.

  In addition, although the power generation capacity of each generator in the power generator (the amount of power that can be output) is not specifically stated, the power generation capacity of a plurality of power generators (generators) depends on the scale of the power generation system and the installation environment Depending on the case, they may be different or the same.

  For example, if the types and the power generation capacities of a plurality of generators constituting the power generation apparatus are the same, the time required for obtaining a desired output after starting becomes the same, and thus control becomes easy. On the other hand, when the types and power generation capacities of the plurality of generators are made different, it is possible to obtain an optimum configuration for the power generation system.

  In the present invention, a software program for realizing the functions of the above-described embodiment (in this embodiment, a program corresponding to the flowcharts of FIGS. 3 and 4 or the time chart of FIG. 5) is directly or directly stored in a system or apparatus. This includes a case where the program is supplied from a remote location and is also achieved by the computer of the system or apparatus reading and executing the supplied program code. In that case, as long as it has the function of a program, the form does not need to be a program.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. That is, the claims of the present invention include the computer program itself for realizing the functional processing of the present invention.

  In this case, the program may be in any form as long as it has a program function, such as an object code, a program executed by an interpreter, or script data supplied to the OS.

It is a block diagram which shows the basic structural example of the electric power generation system which concerns on this invention. It is a figure which shows the example of the some image imaged with the color CCD camera. It is an operation | movement flowchart regarding starting of the diesel generator in 1st Embodiment of an electric power generation system. It is an operation | movement flowchart regarding the stop of the diesel generator in 1st Embodiment of an electric power generation system. It is a time chart which shows the state of the signal regarding the diesel generator in 1st Embodiment. It is a block diagram which shows the specific structure of 2nd Embodiment. It is a block diagram which shows the specific structure of 3rd Embodiment. It is a block diagram which shows the structure of a common solar power generation system. It is a time chart explaining the starting timing of the diesel generator of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photovoltaic power generation system 2 Solar cell 3 Grid connection inverter 4 Electric power system 5 Electric power generation apparatus 6 Load 10 Electric power generation system 20 Electric power generation control apparatus 21 Imaging camera 23 Prediction means 24 Start-up means 26 Red filter 30 Solar cell 50 for light intensity measurement 50 Control means

Claims (9)

Power generation for controlling the plurality of power generation devices in a power generation system including a solar cell, a grid interconnection inverter that converts the output of the solar cell to output to the power system, and a plurality of power generation devices connected to the power system A control device,
Predicting means for predicting the output of the solar cell after a predetermined time;
Starting means for controlling a starting state of the plurality of power generation devices based on a predicted change in output so that a total of power output from the solar cell and the power generation device does not decrease in the power system; A power generation control device comprising: The predetermined time is longer than the time required for the power generator to start up,
When the control means determines that the amount of decrease in the output of the solar cell predicted after the predetermined time cannot be compensated for by the already-started power generation device, the control means considers the time required for startup and The power generation control device according to claim 1, wherein the power generation device is activated. It further comprises imaging means for taking images of at least the surroundings of the sun at predetermined time intervals,
2. The cloud information acquisition means for acquiring information relating to a cloud having a predetermined size or more around the sun based on a plurality of images taken by the imaging means. Or the electric power generation control apparatus of 2.   The power generation control device according to claim 3, wherein the information about the cloud includes information on a cloud position, a moving direction, and a moving speed.   5. The power generation control device according to claim 3, wherein the imaging unit is any one of a color imaging camera, a monochrome imaging camera, a color imaging camera with a filter, and a monochrome imaging camera with a filter.   6. The power generation control device according to claim 1, wherein the prediction unit includes a solar information acquisition unit that acquires information on a position, a movement direction, and a movement speed of the sun.   The prediction unit includes a cloud information acquisition unit that acquires information on a cloud having a predetermined size or more around the sun based on outputs of a plurality of light intensity measurement units installed at a distance. The power generation control device according to claim 1 or 2. Solar cells,
A grid-connected inverter that converts the output of the solar cell and outputs it to the power system;
A plurality of power generators connected to the power system;
A power generation control device for controlling the plurality of power generation devices,
Predicting means for predicting the output of the solar cell after a predetermined time;
Starting means for controlling a starting state of the plurality of power generation devices based on a predicted change in output so that a total of power output from the solar cell and the power generation device does not decrease in the power system; And a power generation control means.   The power generation system according to claim 8, wherein the plurality of power generation devices include at least one of a fuel cell, a device using an internal combustion engine as a power generation unit, and a hydroelectric generator.

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