KR20100032748A - Apparatus and method for pitch angle control of wind turbine - Google Patents

Abstract

PURPOSE: A pitch control part and a method of an aerogenerator which controls a pitch is provided to improve the low voltage conquest capability of aerogenerator by controlling a pitch angle. CONSTITUTION: A pitch control part and a method of an aerogenerator comprises a generator comparison part, a reference pitch value calculating part(20), and a pitch angle compensation part(40) and a pitch servo part(30). The error signal is produced based on the difference of the generator comparison part. The reference pitch value calculating part produces the standards pitch angle by using the error signal. The pitch angle compensation part produces a compensation pitch angle. The pitch servo part produces the pitch angle by using the standards pitch angle and compensation pitch angle.

Description

Apparatus and Method for pitch angle control of wind turbine}

The present invention relates to a pitch control device and method of the wind power generator, and more particularly to a pitch control device and method of the wind power generator for controlling the pitch angle of the wind power generator according to the overvoltage generated in the generator when the system low voltage.

Wind power generation uses no-pollution and infinite wind scattered everywhere, so there is little impact on the environment and the land can be used efficiently.

In addition, wind power generation is a new energy generation technology that can compete with existing power generation in the case of large-scale power generation.

According to the prior art, the wind power generation system uses a UPS (Uninterruptible Power Supply), which is combined with the generator controller and the blade pitch control device in the event of low voltage, to continue the grid connection of the wind generator. In other words, when a low voltage occurs, the UPS instantly disconnects the generator from the grid and supplies the UPS capacity power to the grid.

However, the conventional wind power generation system may take a certain amount of time to reconnect the grid, which may cause undesirable conditions for grid stabilization, and the use of additional equipment such as a UPS may result in an increase in cost in consideration of the trend toward larger capacity of the wind generator. There is a problem.

In addition, the conventional wind power generation system cannot guarantee the destruction of the generator-side converter due to the high current of the generator rotor, which may occur when the system is low voltage only by the reaction speed of the blade pitch control device, and furthermore, it is undesirable to be released from the system. There is a problem with entering the mode.

The present invention is to solve the above problems of the prior art, compensation for the voltage fluctuations in the overvoltage or grid connection point caused by the overcurrent flowing into the converter from the generator side when the system low voltage is accumulated in the DC capacitor It is an object of the present invention to provide a pitch control apparatus and method of a wind generator for generating a pitch angle.

According to one aspect of the invention, there is provided a pitch control device for controlling the pitch of the wind generator.

Pitch control apparatus according to an embodiment of the present invention is a generator comparison unit for calculating an error signal based on the difference between the generator measurement signal and the generator reference signal according to the operation of the wind generator, by using the error signal reference pitch angle A reference pitch angle calculator for calculating a compensation pitch angle calculator for calculating a compensation pitch angle using an error voltage of a DC capacitor included in a power converter connected to the wind generator or an error voltage of a grid connection point of the wind generator; It may include a pitch servo unit for calculating a pitch angle by using the reference pitch angle, the compensation pitch angle.

According to another aspect of the present invention, there is provided a recording medium readable by an electronic device for executing the pitch control method of a wind generator.

According to an embodiment of the present invention, a recording medium readable by an electronic device may include measuring a voltage of the wind generator, calculating an error voltage based on a difference between the measured measurement voltage and a reference voltage, and calculating the error voltage. Calculating a compensation pitch angle using the control pitch; and controlling the pitch angle using the compensation pitch angle.

The present invention has the effect of improving the system's ability to overcome the system low voltage by controlling the pitch angle of the wind generator by detecting the overvoltage induced by the DC capacitor of the power converter connected to the generator when the system low voltage occurs above the rated voltage.

In addition, the present invention by controlling the pitch of the wind power generator by detecting a voltage induced above the rated voltage when the voltage fluctuations in the grid connection point, it is possible to continuously operate the grid connection point voltage of the wind generator within the reference voltage range There is.

In addition, the present invention can achieve a stable power quality by implementing an efficient power generation system by preventing the voltage rise of the DC capacitor due to the system low voltage.

In addition, the present invention has the effect that the grid connection point voltage is operated within the reference voltage range to maintain a stable grid connection of the wind generator having a pitch control device regardless of the generator type to obtain a stable power quality.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1A is a view illustrating a relationship between a pitch control device, a compensation pitch angle calculator, and a wind power generation system according to an exemplary embodiment of the present invention.

Referring to FIG. 1A, the compensation pitch angle calculator 40 measures the voltage of the DC capacitor 3 of the wind power generation system, calculates the compensation pitch angle according to the variation of the measured voltage, and transmits the compensation pitch angle to the pitch control device 10. Thus, the pitch angle of the wind power generation system can be controlled.

Here, the wind power generation system may include a power generator 2 connected to the generator 1 and the generator 1 and converting the power produced by the generator 1. In addition, the power converter 2 may include a DC capacitor 3, and when a system low voltage is generated, an overcurrent may flow into the DC capacitor 3 to generate an overvoltage.

Wind power generation systems generally have a pitch control device 10 for controlling the pitch angle. Here, the pitch control device 10 detects a change in driving speed, output, etc. of the wind generator and controls the pitch angle according to the change amount.

Compensation pitch angle calculation unit 40 according to the present invention generates a compensation pitch angle according to the voltage variation of the DC capacitor 3 of the power converter 2 connected to the wind power generator to transmit to the pitch control device 10, The pitch angle of the wind generator can be controlled.

Hereinafter, the pitch control device 10 and the compensation pitch angle calculator 40 according to the present invention will be described later with reference to FIGS. 2 to 3.

1B is a view illustrating a relationship between a pitch control device, a compensation pitch angle calculator, and a wind power generation system according to another exemplary embodiment of the present invention.

Referring to FIG. 1B, the compensation pitch angle calculator 40 may control the pitch angle of the wind power generation system by measuring the voltage of the grid connection point of the wind power generation system and calculating the compensation pitch angle according to the variation of the measured voltage. have.

The wind power generation system generally includes a pitch control device 10 for controlling the pitch angle. Here, the pitch control device 10 detects a change in driving speed, output, etc. of the wind generator and controls the pitch angle according to the change amount.

Compensation pitch angle calculation unit 40 according to the present invention by generating a compensation pitch angle according to the voltage change of the grid connection point of the wind power generator and transmits to the pitch control device 10, it is possible to control the pitch angle of the wind generator. .

Hereinafter, the pitch control device 10 and the compensation pitch angle calculator 40 according to the present invention will be described later with reference to FIGS. 2 to 3.

2 is a block diagram showing a pitch control device according to an embodiment of the present invention. More specifically, FIG. 2 is a block diagram illustrating a pitch control device 10 including a compensation pitch angle calculator 40 according to an exemplary embodiment of the present invention. Here, the compensation pitch angle calculation unit 40 according to the embodiment of the present invention may be included in the pitch control device 10, it may be implemented as an external device connected to the pitch control device 10.

In addition, the pitch control device 10 according to the present invention is a device for controlling the pitch angle that can obtain the maximum output from the energy of the wind. The power generation system including the pitch control device 10 according to the present invention is preferably applied to the wind power generation system, it will be apparent to those skilled in the art that can be applied to other power generation systems that require pitch control.

Referring to FIG. 2, the pitch control apparatus 10 is connected to the reference pitch angle calculator 20 and the reference pitch angle calculator 20 to operate by the reference pitch angle generated by the reference pitch angle calculator 20. The pitch servo unit 30 may be included.

In addition, the pitch control apparatus 10 may further include the compensation pitch angle calculator 40 described above with reference to FIG. 1.

Hereinafter, it is assumed that the pitch control device 10 includes a compensation pitch angle calculation unit, and the present invention will be described.

Hereinafter, the pitch control device 10 will be described in detail with reference to FIG. 2.

The reference pitch angle calculator input (e _x = X _ref -X) is an error signal input to the reference pitch angle calculator 20. The error signal may be a generator driving speed difference, a generator output difference, or the like, and may be preset by the user. That is, X is a measurement signal according to the generator operation, X _ref may be a designated reference signal.

In addition, it will be apparent to those skilled in the art that the generator drive speed may be the rotational speed of the generator drive shaft and may be proportional to the output of the generator.

For example, assuming that the pitch controller input is a generator drive speed difference, X is a value for measuring the generator drive speed, and X _ref is a generator speed reference value preset by the user. Thus, the error signal e _x of the generator speed can be calculated using the generator speed measurement value X and the generator speed reference value X _ref .

Next, the reference pitch angle calculation unit 20 calculates a reference pitch angle corresponding to the input error signal e _x = X _ref -X. Here, the reference pitch angle calculator 20 may be configured as a linear controller. Here, the linear controller may include a proportional controller, a proportional differential controller, a proportional integral controller, or a proportional integral differential controller.

For example, when the reference pitch angle calculator 20 is configured as a proportional integral controller, the reference pitch angle calculator 20 may calculate the reference pitch angle by Equation 1 below.

[Equation 1]

Here, F is assumed to be a proportional integral controller. t is the time, and the unit is second, the controller's proportional value is 1, the integral value is 5, the unit is degree / rpm, and when the error rate is 5 rpm, the output value at time 0.2 seconds The pitch angle is 5 degrees. That is, it can be calculated as follows.

When the reference pitch angle calculation unit 20 receives an error signal, the reference pitch angle calculation unit 20 calculates a value that compensates for the error signal by a value corresponding to the error signal, and the calculated value becomes a reference pitch angle.

Here, the reference pitch angle is a pitch angle calculated by the reference pitch angle calculator 20 to compensate for a difference between the preset reference value X _ref and the measured value X, and the input value of the pitch servo unit 30 is do.

Next, the pitch servo unit 30 receives a reference pitch angle from the reference pitch angle calculator 20, and receives a compensation pitch angle from the compensation pitch angle calculator 40 to calculate the pitch angle. Here, the pitch angle is input to the pitch servo unit 30 as a feedback.

For example, the pitch servo unit 30 may calculate the pitch angle by the following equation (2).

[Equation 2]

Here, F is assumed to be the same as the primary system with pitch servo. t is time (unit is second), and the unit of the reference pitch angle, the compensation pitch angle, and the feedback pitch angle is degrees. The input pitch angle is 2.2 degree, the compensation pitch angle is 3 degree, the feedback pitch angle is 4 degree, the system constant is 5, and the unit is 1 / sec. The pitch angle, which is the output value at time 0.2 seconds, is 0.92 degree. That is, it can be calculated as follows.

3A is a block diagram illustrating a compensation pitch angle calculator according to an embodiment of the present invention, and FIG. 3B is a block diagram of the compensation pitch angle calculator according to an embodiment of the present invention.

Referring to FIGS. 3A and 3B, the compensation pitch angle calculator 40 compares the measured voltage measured by the DC capacitor 3 with a preset DC capacitor 3 reference voltage to calculate an error voltage ( 42), a compensation pitch angle calculator 46 for calculating a compensation pitch angle may be included.

First, the voltage comparator 42 compares the measured voltage V measured by the DC capacitor 3 and the reference voltage V _ref of the DC capacitor 3 to calculate an error voltage e _{V that} is a voltage difference.

Here, the reference voltage V _ref is a voltage for stably operating the system and stably supplying power, and may be preset by the operator corresponding to the measured voltage V. FIG.

Next, the compensation pitch angle calculator 46 calculates a compensation pitch angle corresponding to the error voltage e _V received from the voltage comparator 42. In other words, the compensation pitch angle calculation unit 46 calculates the compensation pitch angle to finally bring the error voltage value to zero using an integrator.

For example, the compensation pitch angle calculator 46 may calculate the compensation pitch angle by Equation 3 as follows.

&Quot; (3) "

Here, F is assumed to be a proportional integral controller. t is time, and the unit is second, the proportional value of controller is 1, integral value is 5, unit is degree / rpm, and when input error voltage is 5V, compensation pitch is output value at time 0.2 seconds The angle is 5 degrees. That is, it can be calculated as follows.

That is, the compensation pitch angle calculation unit 46 has an input as an error voltage and an output as a compensation pitch angle. Here, the compensation pitch angle is used as an input value of the pitch servo unit 30 of the pitch control device 10. In addition, the compensation pitch angle calculator 46 may be any one or a combination of a proportional controller, a proportional derivative controller, a proportional integral controller, or a proportional integral differential controller, and performs linear control.

The compensation pitch angle calculator 40 according to another embodiment of the present invention may further include a compensation active power calculator (not shown) for calculating the compensation effective power. That is, the compensation pitch angle calculation unit 40 according to another embodiment of the present invention includes a voltage comparison unit 42 which calculates an error voltage by comparing the measured voltage measured at the grid connection point with a preset grid connection point reference voltage, A compensation active power calculator (not shown) for calculating a compensation active power value, and a compensation pitch angle calculator 46 for calculating a compensation pitch angle may be included.

Here, the compensation active power calculator calculates an active power value that compensates for the error voltage by using the error voltage received from the voltage comparator 42. The calculated active power value is transmitted to the compensation pitch angle calculator 46.

For example, the compensation active power calculator may calculate the compensation active power value by Equation 4 as follows.

[Equation 4]

Here, F is assumed to be a proportional integral controller. t is time and unit is second. When the controller proportional value is 1, the integral value is 5, the unit is Watt / V, and the input error voltage is 0.5V, the compensation effective power value as the output value is 0.55 watt (watt). That is, it can be calculated as follows.

In addition, the compensation pitch angle calculator 46 may calculate the compensation pitch angle by using Equation 4 above.

That is, when the compensation effective power as the input value of the compensation pitch angle calculator 46 is 0.55 Watt, the compensation pitch angle as the output value is 1.1 degree. Here, the controller proportional value is 1, the integral value is 5, and the unit is degree / Watt. That is, it can be calculated as follows.

The active power value is calculated because the voltage and the active power have a close relationship, and the voltage changes according to the change of the active power.

That is, the compensation active power calculator calculates a compensation active power value that compensates for the error voltage by a value corresponding to the error voltage.

The compensation active power calculator and the compensation pitch angle calculator 46 may be implemented as one controller. Thus, in one controller, the input may be an error voltage and the output may be a compensation pitch angle.

In addition, the compensation active power calculator and the compensation pitch angle calculator 46 may be any one or a combination of a proportional controller, a proportional derivative controller, a proportional integral controller, or a proportional integral differential controller, and perform linear control.

4 is a flowchart illustrating a method of generating a compensation pitch angle according to an embodiment of the present invention. More specifically, FIG. 4 is a flowchart illustrating a method of generating a compensation pitch angle for performing a pitch control method according to an exemplary embodiment of the present invention.

Hereinafter, the functions of each configuration described with reference to FIGS. 3A and 3B are processed in the compensation pitch angle calculation unit 40 according to the embodiment of the present invention. In order to understand the present invention, the compensation pitch angle calculation is performed. The part 40 is mainly described.

Referring to FIG. 4, the compensation pitch angle calculator 40 measures the voltage at the DC capacitor 3 (S510). In addition, the compensation pitch angle calculator 40 may measure the voltage at the grid connection point in another embodiment.

Subsequently, the compensation pitch angle calculator 40 calculates an error voltage using the measured voltage and the reference voltage of the DC capacitor 3 (S520). In addition, the compensation pitch angle calculator 40 may calculate an error voltage using the measured voltage and the reference voltage of the grid connection point. Here, the reference voltage may be preset by the user in correspondence with the measured voltage.

Subsequently, the compensation pitch angle calculator 40 calculates a compensation pitch angle corresponding to the error voltage using the error voltage (S530). In addition, as another embodiment, the compensation pitch angle calculator 40 may calculate a compensation active power value corresponding to the error voltage, and calculate a compensation pitch angle corresponding to the compensation active power value using the compensation active power value. have.

Pitch control method according to an embodiment of the present invention is implemented in the form of program instructions that can be executed by various computer means may be recorded on a computer readable medium. Computer-readable media may include, alone or in combination with the program instructions, data files, data structures, and the like.

The program instructions recorded on the computer readable medium may be those specially designed and constructed for the present invention, or may be known and available to those skilled in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Hardware devices specially configured to store and execute program instructions such as magneto-optical media and ROM, RAM, flash memory and the like. In addition, the above-described medium may be a transmission medium such as an optical or metal wire, a waveguide, or the like including a carrier wave for transmitting a signal specifying a program command, a data structure, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.

The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

Figure 1a is a diagram showing the relationship between the pitch control device, the compensation pitch angle calculation unit and the wind power generation system according to an embodiment of the present invention.

Figure 1b is a diagram showing the relationship between the pitch control device, the compensation pitch angle calculation unit and the wind power generation system according to another embodiment of the present invention.

2 is a block diagram showing a pitch control device according to an embodiment of the present invention.

Figure 3a is a block diagram of a compensation pitch angle calculation unit according to an embodiment of the present invention.

3B is a block diagram of a compensation pitch angle calculator according to an exemplary embodiment of the present invention.

4 is a flowchart illustrating a method of generating a compensation pitch angle according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10: pitch control device 20: reference pitch angle calculation unit

30: pitch servo unit 40: compensation pitch angle calculation unit

42: voltage comparison section 46: compensation pitch angle calculation section

Claims (8)

In the pitch control device for controlling the pitch of the wind power generator, A generator comparator configured to calculate an error signal based on a difference between the generator measurement signal and the generator reference signal according to the operation of the wind generator; A reference pitch angle calculator configured to calculate a reference pitch angle using the error signal; A compensation pitch angle calculator configured to calculate a compensation pitch angle by using an error voltage of a DC capacitor included in a power converter connected to the wind generator or an error voltage of a grid connection point of the wind generator; And And a pitch servo unit configured to calculate a pitch angle using the reference pitch angle and the compensation pitch angle. The method of claim 1, The generator measurement signal is a measurement signal for the rotational speed of the generator drive shaft or the output of the generator, the generator reference signal is a pitch control device, characterized in that the preset reference signal corresponding to the generator measurement signal. The method according to claim 1 or 2, And the reference pitch angle calculator comprises a linear controller. The method according to any one of claims 1 to 3, The error voltage is The measured voltage and the measured voltage at the grid connection point of the wind generator or calculated based on the difference between the voltage measured in the DC capacitor included in the power converter connected to the wind generator and the preset reference voltage corresponding to the measured voltage. The pitch control device, characterized in that it is calculated based on the difference of the predetermined reference voltage corresponding to the predetermined voltage. The method according to any one of claims 1 to 4, The compensation pitch angle calculation unit, A compensation active power calculator configured to calculate a compensation active power value using the error voltage; And And a compensation pitch angle calculator configured to calculate a compensation pitch angle using the compensation active power value. In a recording medium readable by an electronic device for implementing a pitch control method of a wind power generator, Measuring a voltage of the wind generator; Calculating an error voltage based on a difference between the measured measured voltage and a reference voltage; Calculating a compensation pitch angle using the error voltage; And And controlling the pitch angle by using the compensation pitch angle. The method of claim 6, Measuring the voltage of the wind generator, The electronic device readable recording medium, characterized in that for measuring the voltage of the DC capacitor or grid connection point of the wind generator. The method according to claim 6 or 7, Calculating the compensation pitch angle using the error voltage, Calculating a compensation active power value using the error voltage; And And calculating a compensation pitch angle by using the compensation active power value.

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