JPS62123999A - Wind power generator - Google Patents

Abstract

PURPOSE:To acquire energy effectively by conducting variable speed control through which a wind-mill is operated by the number of revolution corresponding to an input to the wind-mill up to the rated number of revolution of the wind- mill. CONSTITUTION:With a wind-mill 1 driving a generator 2, the pitch angle of a blade is kept constant at the rated number of revolution or less, and the pitch angle is controlled so as to reach the rated number of revolution in an operation region of the rated number of revolution or more. A comparator 84 transmits a deviation between an output command signal PREF corresponding to the number of revolution N of the wind-mill 1 and an output P over a compensation circuit 85. A comparator 86 transmits a deviation between the number of revolution N and an output from the compensation circuit 85 over a field power supply circuit 89. The generated output of the generator 2 is fed to a system through a rectifier 3 and a converter 4. The converter 4 is controlled in response to the generated output while being synchronized with the phase of the system.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention provides a wind turbine that converts power energy into shaft power;
The present invention relates to a wind power generation device using a synchronous generator or a DC generator that converts shaft power into electric power, and is suitable for use as a power generation device for peak cut in grid connection.

(Prior Art) Conventionally, as a means (generator) for converting the shaft power of a wind turbine into electric power in the power generation device 5, a synchronous DC machine or a dielectric generator has been used.

However, in general, with a synchronous machine or a DC converter, in the main operating range from the rated wind speed at which the wind turbine's rated output is P to the wind speed at which the wind turbine stops operating and generates power, Constant rotation/number control is performed to keep the rotation speed constant using blade bit control. For this reason, as will be described later, the "circumferential speed ratio" determined by the wind speed to the circumferential speed of the wind turbine is not constant, and it cannot be said that energy is being effectively acquired. Moreover, as mentioned above, constant rotation speed control operation causes large torque fluctuations due to sudden changes in wind conditions, and in order to withstand this, the structure and quality must be uniform. This also caused an increase in costs.

In addition, synchronous power generation is also possible (by using a DC generator in the field V11
There was a demand for effective power regeneration through lightning current control and efficient interconnection with the power grid.

On the other hand, many of those using induction<i are operated by being connected to the existing power system, and those that use wind speed as the operation control means are common. In this case, power generation is difficult at high viscosity control because the locations where the speed is measured are different.
Therefore, sometimes a situation may occur where the induction motor does not operate as a generator but as an electric motor.Also, in order to connect directly to the grid, it will operate at around 50 / 60 I-l z, and the rotation speed will be constant. The situation was similar to that of control, and had the same problems as described above.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems.
Variable speed control that operates at the rotation speed according to the input of the car 11 to 7
1. By doing so, it is possible to absorb 1 to 1 torque fluctuations due to rapid changes in the flea condition, reduce costs in terms of structure and materials, and regenerate a large amount of energy at low cost. It uses wind turbine rotation speed information instead of wind speed information, and controls the field current of a synchronous generator or DC generator.
By doing so, it is possible to easily control the wind power generation device with a highly accurate and almost constant circumferential speed ratio, thereby achieving effective energy acquisition and improving reliability, as well as creating a wind power generation device that can be efficiently connected to the grid. The purpose is to provide.

(Structure of the Invention) The present invention relates to a wind turbine H that converts wind energy into power whose blade pitch angle can be controlled, a synchronous generator or DC power generator that converts this power into electric power, and the above-mentioned wind turbine. a field controller that controls the field tifl current of the generator so as to obtain a generator output commensurate with the input based on rotational speed information; and a converter that sends the electric power recovered by the generator to the grid. The converter is equipped with a driving means for detecting the phase of the grid, synchronizing the converter with the grid, and performing phase control according to the regenerated power, and the converter detects the phase of the grid, and the converter is equipped with a drive means for controlling the phase according to the regenerated power, and the converter detects the phase of the grid, synchronizes the converter with the grid, and performs phase control according to the regenerated power. The pitch angle of the blade is kept constant in the operating range, and the pitch angle of the blade is controlled so that the wind di rotational speed falls within the set rotational speed range in the operating range above the rated rotational speed. It is.

With this configuration, variable speed control operation is performed at the wind turbine rotation speed (rotation speed) corresponding to the wind speed below the wind turbine rotation speed that generates the rated output, and torque fluctuations due to changes in wind conditions are used as inertia to absorb C. In addition, the excitation current of the generator is controlled based on the wind turbine rotation speed information, and the output power commensurate with the wind turbine input is obtained, and for the reasons described below, operation control at a substantially constant circumferential speed ratio is easily performed. This enables effective acquisition of energy. In general, power can be supplied to the grid according to the energy generated by the wind turbine.

Below, by performing rotational speed control 211 that matches the wind speed, constant peripheral speed ratio control is possible and the effective number of energy is 1.
The reason why n can be achieved will be explained.

The basic characteristics of the output from a propeller-type wind turbine are as follows: ρ: air density, V: wind speed, Cp: power coefficient, R: propeller radius, ω: angular velocity power coefficient Cp = 2P/, oπR2v3・(2) circumference Speed ratio TSR=ωR/v・(3) Here, in order to obtain the maximum efficiency as a wind turbine, it is sufficient to carry out control to always maintain the maximum value of the power coefficient Co, which makes it possible to obtain the maximum effective re-energy. becomes.

As shown in Fig. 2, the power coefficient Cp characteristic of a wind turbine has its maximum weight depending on the pitch angle β of the wind turbine blades.
Moreover, it is a function of the circumferential speed ratio TSR.

Therefore, when the pitch angle β of the wind turbine blades is set to a certain value, the circumferential speed ratio TS at which the power coefficient fllcp is maximum is
R is determined.

However, as can be seen from equation (3) above, the circumferential speed ratio TSR is determined by the angular velocity ω and the J-speed V.
If SR is to be kept constant, if the wind speed V changes, the rotational speed must also change.

Therefore, if the pitch angle β of the wind turbine blades is fixed to maximize energy acquisition in accordance with the wind conditions, it is sufficient to perform rotational speed control in accordance with the wind speed, that is, constant circumferential speed ratio control.

Now, if the circumferential speed ratio TSR at which the power coefficient Cp is maximum is Ω, the output P of the wind turbine is expressed as a function of the rotation speed N like a thorn.

Ω=ωR/■...(4) ■-ωR/Ω...(4゛) ω-2πN/60...(5) where N: Wind turbine rotation speed (ram) (5), (4' ) From the formula, v=R/Ω−yrN/30
・(6)<1), P='y2P7rR' from equation (6)
Cnmax (RyrN/30Ω)' = 1.8
X 10'ρR5Cp max (1/Ω3)N3...
(7) From this equation (7), it can be seen that the output P of the wind turbine is proportional to the cube of the rotation speed N, and it can be seen that constant circumferential speed ratio control can be performed using the rotation speed N as information.

The characteristics of the power coefficient Cp, output P, and torque T of these wind turbines with respect to the rotational speed N are shown in FIG. In the figure, the horizontal axis shows the rotation speed N, and the vertical axis shows the power coefficient Cp (solid line), output P (dashed line), and torque T at each wind speed ■1 to v7.
(dotted chain line) shows the characteristic curve, and line P shows the rated load. As can be seen from the figure, the output P shows the maximum value in the circulation number N where the maximum value of the power coefficient Go<Cpmax) at each wind speed v1 to v7 is obtained, and therefore, Cp
By maintaining laX, the output P has the characteristics of the curve (A), and the torque T at that time has the characteristics of the curve (B). That is, by keeping the power coefficient Cp8 at the maximum value, the level of the output P is uniquely determined by the rotation speed N of the wind turbine. Therefore, if the field current of the synchronous generator or DC generator is controlled so that a predetermined output P determined according to the rotational speed N is obtained, energy can be obtained effectively.

In Fig. 3, NVC is the cut-in rotation speed corresponding to the wind speed (VC) at which power generation starts, N
is the rated rotation speed corresponding to the rated wind speed V[V +, at which the wind turbine produces its rated output.

(Embodiment) FIG. 1 shows the configuration of an embodiment of the apparatus of the present invention. In the same figure, a wind turbine 1 that converts wind turbines into power is a mechanical bidgecon 1 to which the pitch angle of the blades can be controlled.
It has a propeller-type rotor having a roll part and a function of transmitting the output of this rotor, that is, shaft power, to a synchronous generator (or DC generator ff1n, hereinafter the same) 2 as a power-to-power converter.

The synchronous generator 2 has a field FJii line 2f, and its output is connected to a converter 4 for system connection (details will be described later) via a rectifier 3 (not necessary in the case of a DC generator).

The rotation speed of the wind turbine 1 is detected by the rotation speed detector 5, and this rotation speed information and the current and voltage information from the current detection circuit 6 and voltage detection circuit 7 of the output of the power generation hall 2 are inputted, and the above-mentioned field A field suppressor 8 is provided to operate the magnetic winding 2f in a predetermined manner. This field controller 8 compares the actual power with a predetermined value obtained by converting the rotation speed into power so that a generator output commensurate with the input to the wind turbine can be obtained based on the rotation speed information. vii current is controlled.

The field controller 8 includes an F/V converter 80 that converts the rotation speed detected by the rotation speed detector 5 into °1 pressure,
Suzuki's rotation speed and power are converted into the output of the F/V converter 80 according to a predetermined relationship (e.g., a cubic curve of the rotation speed), and an output signal PIl[:F is output. A circuit 81 , a multiplier 82 that calculates power by multiplying the outputs of the current detection circuit 6 and voltage detection circuit 7 , an amplifier circuit 83 , and an output signal pn1r of the rotation speed-power conversion circuit 81 and the amplifier circuit 83 a compensating circuit 85 for inputting the output of the comparing means 84 to match the characteristics of the system;
A comparison means 86 for comparing the output of the V converter 80 and the output of the compensation circuit 85, an amplifier circuit 87, and a pulse width modulation circuit (P
The converter 4 is a three-phase inverter using active elements such as transistors as switching elements. and
This three-phase output line is connected to the system 20 (commercial power supply). Note that Cylisk may be used as the element constituting the converter 4.

A phase detection transformer 18 and a first stage of current detection 19 are connected to the output line, and the detected phase and the output of the amplifier circuit 83 with the output C of the generator 2 are input to the current command circuit 21, and the current The output of the command circuit 21 and the current detection value via the current detection amplifier circuit 22 are connected to the comparator 2.
3, and the comparison result is input to the gate drive circuit 25 via the compensation circuit 24 for matching the characteristics of the system.

The output of the gate drive circuit 25 drives the active elements of the converter 4. These phase detection 1
~Lance 18, current detection means 19, current command circuit 21,
The gate drive circuit 25 'etc. is the drive means 2 of the converter 4.
6, so that the converter 4 is connected to the system 20
1, the phase is controlled according to the output of the generator 2, that is, the energy generated by the wind turbine, and
It sends out electric power to the grid 20 and performs the J function.

Next, the control chart 1 for the wind turbine 1 and the generator 2 in the wind power generator shown in -F will be explained with reference to FIG.

In the figure, the horizontal axis shows the wind speed V, and the vertical axis shows the output 11 rotation speed N. ■8 is the starting wind speed at which the wind turbine begins to rotate, Vc is the cut-in wind speed at which power generation begins, and Vl is the rated output of the wind turbine. The obtained rated wind speed, VCO is the wind speed when the wind turbine is stopped and feathered to prevent wind energy from escaping, PL is the rated output as a wind power generator, N is the cut-in rotation speed, vL is the rated rotational speed, and in the operating range up to this rotational speed, the pitch angle of the blade is constant, and in the operating range above this rotational speed, the pitch angle of the blade is adjusted so that the small rotational speed Tfi is within the specified rotational speed range. is controlled.NN
is the no-load setting rotation speed of the wind turbine, 10% above NN is the control rotation speed range controlled by pitch control, the curve PR is the loss power, and the period from ■5 to vo is the mechanical loss and gear of the generator. Transmission loss (square curve) of puller 7, excitation loss of generator is added during VC, excitation loss and mechanical loss between v ~ ■ L[G;
f constant).

In FIG. 4, the operating conditions are as follows.

■Delivery: No power is generated between wind speeds O~■3, and the above field controller 8
Do not drive.

■Startup: Wind speed■ Between ~Vc, wind energy can be used as energy to rotate the windmill.

■Cut-in - The wind power generator becomes ready to start generating electricity and excite the generator 2.

■Load control region: Wind speed■ During the period from ■ to V1, the maximum output control explained in FIG. 3 is performed. In other words, the generated power is controlled so that the rotational speed matches each wind speed situation. As a result, the output P exhibits an output characteristic proportional to the cube of the wind speed (number of rotations), and maximum output control is performed at each number of rotations.

The rotational speed N rises from VS and rises while being balanced with the moment of inertia of the wind turbine, ■. After that, it will be operated in proportion to the wind speed. J3, the process in which the rotation speed decreases by 1 and the process in which the rotation speed decreases as the wind weakens are shown by arrows.
It exhibits hysteresis characteristics as shown in FIG.

■Load fixed region: Wind speed ■ ~ vCo darkness keeps the output P constant, releases the input calm energy through mechanical pitch control, and controls the rotation speed N to a range of 10% above NN.

■Standby: Wind speed VC. In the above wind conditions, the wind energy exceeds the purchasing capacity, so a mechanical governor is used to feather the wind turbine to release the energy and maintain the wind turbine in a safe condition.

In such control and operation, as mentioned above, the output of the wind turbine that takes the power coefficient C max point is determined based on the rotation speed of the wind turbine, so the rotation speed -
The power conversion circuit 81 converts the output signal PR[l- to the output signal PR[l-, which is compared with the output P of the generator 2, and further compared with the output of the F/V converter 80 to generate a field in the PWM circuit 88, etc. By controlling the field current value to the winding 2f, the wind turbine is variably controlled, and as a result, the width is operated close to a constant circumferential speed ratio. Therefore, energy can be effectively acquired, and torque changes tjh due to sudden changes in wind conditions can be sufficiently absorbed.

At the same time, the converter 4 synchronizes with the grid and performs phase control according to the regenerated power of the generator 2, which enables efficient grid connection and improves the operating load factor by cutting power peaks in the grid. It can also contribute to

In addition, in the above embodiment, it was explained that the field controller 8 is provided, but a white porcelain type one in which the generator itself has this function may be used, or a converter such as a converter may be used. .

Also, the times above! In the 1/i number-power converter 81, an output signal P proportional to the cube of the rotation speed N of Ill m
Although the case where constant circumferential speed ratio control is performed using PEF has been described, the present invention is not limited to this, and the rotation speed N of the wind turbine
Even if the output is proportional to or proportional to 2 (No. 5), it is possible to obtain energy more effectively than with conventional constant rotation speed control.

(Effects of the Invention) As described above, according to the present invention, the field of the synchronous generator or DC generator is adjusted so that the power generation output commensurate with the input of the wind turbine is adjusted by 1!7 based on the wind turbine rotation speed information. By controlling the current and keeping the pitch angle of the wind turbine blades constant in the operating range up to the rated rotational speed of the wind turbine, and controlling the pitch angle in the operating range beyond that, the wind turbine maintains an approximate constant circumferential speed of t7. Ratio control operation is used to efficiently regenerate a large amount of energy, and variable rotation speed control means that the wind turbine is operated at a rotation speed that corresponds to human power, so torque fluctuations due to sudden changes in wind conditions can be avoided. Can be absorbed and structured
A'j +A In terms of quality, high costs can be avoided and reliability can be improved.

Furthermore, the control system only needs to control a small field current, which enables economical design compared to controlling the output power itself. In addition, since power is sent out under phase control while being synchronized with the grid using a converter according to the regenerated power, efficient grid connection is possible.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of an embodiment of the wind power generation device of the present invention, Fig. 2 is a characteristic diagram of the power coefficient with respect to the circumferential speed ratio in a wind turbine for explaining the present invention, and Fig. 3 is a similar diagram of the rotation of the wind turbine. The power coefficient of 1j to the number. Output, 1-lux characteristic diagram, FIG. 4 [This is a control chart 1 for explaining the control of the device. 1...Windmill, 2...Municipal machine (also (DC generator)), 2F...Field winding, 4...Converter, 5...
- Rotation speed detector, 8... Field controller, 26... Drive means. Patent applicant Yamaha Motor Co., Ltd. Agent Patent attorney Etsushi Kotani 1
! Chief 1) Masamukai Patent Attorney Yasuo Itaya 2nd Diagram - Kumihosei, TS Shaka

Claims (1)

[Claims] 1. A wind turbine that converts wind energy into power whose blade pitch angle can be controlled, a synchronous generator or DC generator that converts this power into electricity, and power generation that matches the input based on the rotation speed information of the wind turbine. It consists of a field controller that controls the field current of the generator so as to obtain the machine output, and a converter that sends the electric power regenerated by the generator to the grid, and the converter detects the phase of the grid and The converter is provided with a driving means for performing phase control in accordance with the regenerated power in synchronization with the grid, and the pitch angle of the blade is constant in the operating range from the start of the wind turbine to the rated rotation speed,
A wind power generation device characterized in that the pitch angle of the blades is controlled so that the wind turbine rotation speed falls within a set rotation speed range in an operating range above the rated rotation speed.