KR20110077139A - Wind turbine control method for reducing peak load - Google Patents

Abstract

PURPOSE: A control method for reducing load of a wind power generator is provided to flexibly cope with a load applied to a wind power generating system to improve the utilization and operability of the wind power generating system. CONSTITUTION: A control method for reducing load of a wind power generator includes the following steps. Information about a wind direction and wind velocity is received from a wind direction sensor and a wind velocity sensor(S23). The concavity error of an average time having one or more time ranges depending on the wind velocity is measured. The concavity is compared with a turbine stop criterion value. If the concavity error is greater than the turbine stop criterion value, a wind power generating system is stopped(S33).

Description

Wind Turbine Control Load Reduction Method {WIND TURBINE CONTROL METHOD FOR REDUCING PEAK LOAD}

The present invention relates to a control method for reducing the load of a wind turbine, and more particularly, it is generated by a yaw error without unnecessarily lowering the utilization and operation rate of the wind power generation system from yaw errors that may occur in various wind conditions. The present invention relates to a control method for reducing a wind turbine load that can protect a wind power system from a load.

Wind power generation system uses windmills of various types to convert wind energy into mechanical energy, and this mechanical energy is driven by a generator to obtain power. It is an infinite clean energy source that does not require transportation and supply of fuel because it uses wind, which is an existing resource, and has no pollution due to heat generation, radioactive leakage, air pollution, etc. unlike the existing generation method using fossil fuel or uranium. It's a way of development.

The general components of the wind power generation system are largely composed of a blade, a power transmission device, a generator, a tower, and a control system, but there are differences depending on a control method, a grid connection method, and a power transmission type. It is divided into geared type and gearless type according to power transmission type.

In the case of the gearless type, there is no power transmission device between the blade rotor and the generator, so it is directly connected and generated. However, most wind turbines currently installed and operated have the speed of the blade rotor input to the power transmission device, and the generator is output. Geared Type is used to determine the output speed up to the speed at which power generation is possible.

Nacelle, the heart of wind power, is typically used for medium to large wind power, with blade and tower connections, generators, power converters, gears and yawing systems. The main function is to allow the wind to be perpendicular to the rotational surface of the blade so that the generator rotates clockwise or counterclockwise to obtain an optimal output, and brakes for wind power protection above the blocking wind speed.

1 is a graph showing a yaw error reference value of a conventional wind power generation system.

As shown in FIG. 1, when the yaw error, which is a difference between the direction of the nacelle and the wind direction, which increases momentarily, is higher than a reference value set using only a single average time, the system is stopped regardless of the wind speed.

Therefore, in case of having a yaw error (turbine stop criterion) irrespective of the conventional single mean time and wind speed, it is difficult to protect the wind power generation system from various wind conditions that may be applied to the wind power generation system. In addition, there is a problem in that the utilization rate and operation rate of the wind power generation system is reduced by causing an unnecessary stop situation.

The present invention has been made to solve the above problems, and from the load generated by the yaw error without unnecessarily lowering the utilization and operation rate of the wind power generation system from the yaw error that can occur in various wind conditions The purpose of the present invention is to provide a control method for reducing a wind turbine load that can protect a power generation system.

The control method for reducing the load of the wind power generator of the present invention for realizing the object as described above receives the information of the wind speed, wind speed from the generator rotation speed, pitch angle information and wind direction sensor, wind speed sensor from the generator encoder, the pitch encoder In the control method for reducing the wind turbine load in the nacelle control unit that functions to stop the wind turbine and to control the direction of the wind blade according to the wind condition, information about the wind direction and the wind speed is obtained from the wind direction sensor and the wind speed sensor. Measuring a yaw error of an average time having one or more time ranges according to the wind speed; Comparing the yaw error of the average time having one or more time ranges according to the wind speed with the turbine stop reference value; And

And stopping the wind power generation system if the yaw error of the average time having one or more time ranges according to the wind speed is greater than the turbine stop reference value.

In addition, when the wind power generator is less than the rated output, the yaw error of the average time having one or more time ranges according to the wind speed can be replaced by a yaw error according to the generator rotation speed measured by the generator encoder.

In addition, when the wind power generator is more than the rated output, the yaw error of the average time having one or more time ranges according to the wind speed can be replaced by the yaw error according to the pitch angle measured by the pitch angle encoder.

In addition, the turbine stop reference value is characterized in that the yaw error of the average time having one or more preset time range according to any one of the wind speed, generator rotation speed and pitch angle.

According to the control method for reducing the load of the wind turbine according to the present invention, the turbine is stopped based on the yaw error of the average time having one or more time ranges according to the wind speed, which is a criterion for stopping the wind power generation system verified in advance from simulation or empirical results. By setting the reference value, it is possible to flexibly cope with the load received by the wind power generation system against the yaw error occurring at various wind speeds, thereby increasing the utilization rate and utilization rate of the wind power generation system.

Hereinafter, the configuration and operation of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Here, the same reference numerals will be used for the same components as the prior art.

2 is a block diagram illustrating a nacelle.

The nacelle refers to the upper part of the tower and includes a generator, a gearbox, a shaft, and the like. In the present invention, the turbine stopping reference value is set based on the yaw error of an average time in which the yaw error according to the external wind condition has one or more time ranges depending on the wind speed. If it exceeds, the control method for reducing the wind turbine load by stopping the wind turbine will be discussed.

As shown in Figure 2, the nacelle 100 receives the information output from the wind direction sensor 10, the wind speed sensor 20 through the interface unit 30, the yaw of the average time having one or more time ranges according to the wind speed And a control unit 40 for comparing and calculating the turbine stop reference value preset based on the error. In addition, although not shown, the control unit 40 of the nacelle receives the generator rotation speed and the pitch angle from the pitch angle encoder from the generator encoder through the interface unit 30.

The control unit 40 of the nacelle compares the external wind sulfur conditions received from the wind direction sensor 10 and the wind speed sensor 20 with the turbine stop reference value to be within a normal range, and controls yawing angles according to the wind direction and wind speed. Is transmitted to the yawing motor 50 and the hydraulic pump driving motor 60 through the interface unit 30 to perform motor control for yawing of the nacelle.

On the other hand, in order to protect the wind power generation system from the load caused by the instantaneous increase in yaw error (difference between the wind direction and nacelle direction), the present invention provides an average time having one or more time ranges according to the wind speed, which is a criterion for stopping the wind turbine. The turbine stop reference value preset based on the urgent error is defined by the wind speed and one or more average times for the yaw error as the measured value verified from the simulation or empirical results in advance and shows one example in Table 1 below.

Table 1

As shown in Table 1, stopping the wind speed system by the mean time (X, Y, Z) having one or more time ranges in which the measurement time range is set differently for each measured wind speed section (E, F, G, H). The turbine stop reference value is set. Since the initial turbine stop reference value is a test value, it is natural that the turbine stop reference value can be changed according to the wind condition in which the wind turbine is installed.

In addition, the turbine stop reference value may be defined as a yaw error of an average time having one or more time ranges set in advance according to any one of the generator rotation speed and the pitch angle. Since all wind speeds correspond to the generator rotor speed before and after the rating, and the pitch angle after the rating, the wind speed section used for the turbine stop reference value is the generator rotation speed section before the rating and the pitch angle after the rating. It can be expressed as a section.

That is, since the generator rotation speed does not increase infinitely with the wind speed and has the rated output, the wind speed and the generator rotation speed correspond one-to-one in the section below the rated output. On the other hand, in the section above the rated power, the wind speed above the rating induces excessive power production, which impedes the wind power generator and applies a high load to the blades. Therefore, to prevent this, the control unit of the nacelle performs pitch control by changing the blade angle. That is, if the wind speed and the pitch angle is one-to-one correspondence before the CUT-OUT wind speed before the rated output, the turbine stop reference value according to the pitch angle can be set in the same way as the turbine stop reference value is set according to the generator rotation speed.

3 is a graph showing the average time (A, B, C) turbine stop reference value according to the wind speed of the present invention. Referring to FIG. 3, the turbine stop reference value is shown as a graph, and the controller continuously monitors the value of the yaw error with respect to the average time having one or more time ranges A, B, and C according to the wind speed. If the reference value is exceeded, the turbine is stopped.

That is, when the yaw error of the average time having each time range according to the current wind speed is located at the lower end of the A graph (turbine stop reference value), the wind generator operates normally, but when it exceeds the A graph, the wind generator is stopped. The same applies to B graphs and C graphs having different time ranges B and C for the same wind speed section.

Here, when determining the reference (turbine stop reference value) for stopping the turbine of FIG. 3, it is possible to set whether to satisfy only one average time according to the wind speed (A) or to satisfy all three (A, B, C). Of course, it can be obvious that the average time can be set to have more than one time range.

Hereinafter, a control method for reducing a wind turbine load of the present invention is disclosed. Here, an embodiment of the present invention will be described with reference to FIG. 3 when a wind speed section E and F is divided into two, and a yaw error of an average time having three time ranges A, B, and C is used.

4 is a flowchart illustrating a control method for reducing a wind turbine load according to the present invention.

As shown in FIG. 4, first, the controller measures the yaw error for each average time (A, B, C) according to the wind speed by using information on the current wind direction and the wind speed from the wind direction sensor and the wind speed sensor through the interface unit. The mean time (A, B, C) according to the wind condition has information about the urine error (S10).

The controller compares whether the measured average wind speed is greater than E, F and determines a section to which the wind speed belongs (S20). If the wind speed is greater than E and less than F, the controller compares the measured urine error by the average time (A) with the turbine stop reference value of the average time (A) according to the current wind speed (S21) to determine the average time (A). If the measurement error is larger than the turbine stop reference value of the average time (A) according to the wind speed, the wind power generation system is stopped.

Next, the control unit determines that the measurement yaw error by the average time A is smaller than the turbine stop reference value of the average time A according to the wind speed, but the measurement time error by the average time B is the average time B according to the current wind speed. In comparison with the turbine stop reference value of (S22), if the wind power generation system is stopped.

Next, the measured yaw error by the average time (B) is smaller than the turbine stop reference value of the average time (B), but the measured yaw error by the average time (C) is compared with the average time (C) turbine stop reference value according to the current wind speed. If the determination is large (S23), the wind power generation system is stopped. The wind power generation system continues to generate power when the three measurement time errors (A, B, C) according to the wind speed are smaller than the turbine stop reference value for each average time (A, B, C).

Next, even when the wind speed is greater than F, it is determined whether to stop the wind power generation by comparing the yaw error of the average time having the respective time range (ABC) and the turbine stop reference value (S31, S32, S33). Since it is the same as the case of larger than E and smaller than F, it is omitted here. In this example, the wind speed section is set to two (E, F), but it is natural to set the wind speed section to a plurality of sections.

That is, according to the yaw error or the yaw tracking and the yaw error generated during the time that cannot be solved by the yaw tracking or the yawing caused by the sudden change of the wind direction, the turbine stop reference value set based on the yaw error of the average time having one or more time ranges according to the wind speed By defining the average time reference value based on each measurement time range, the wind power generation system is stopped because it is not able to flexibly cope with various external wind conditions by using the average value or median value for a single average time for the conventional instant yaw error. By avoiding this, the utilization rate and utilization rate of the wind power generation system can be increased.

It is apparent to those skilled in the art that the present invention is not limited to the above embodiments and can be practiced in various ways without departing from the technical spirit of the present invention. will be.

1 is a graph showing a yaw error reference value of a conventional wind power generation system,

2 is a configuration block diagram of a nacelle;

3 is a graph showing the average time (A, B, C) turbine stop reference value according to the wind speed of the present invention,

4 is a flowchart illustrating a control method for reducing a wind turbine load according to the present invention.

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

10: wind direction sensor 20: wind speed sensor

30: interface unit 40: control unit

50: yawing motor 60: hydraulic pump drive motor

70: generator encoder 80: pitch angle encoder

100: nacelle

Claims (4)

Generator encoder, pitch encoder, generator rotation speed, pitch angle information and wind direction sensor, wind direction and wind speed information input from wind speed generator according to the wind conditions and wind direction control function such as blade direction control function In the control method for reducing the wind power generator load in the nacelle control unit, Measuring the yaw error of an average time having one or more time ranges according to the wind speed by receiving information on the wind direction and the wind speed from the wind direction sensor and the wind speed sensor; Comparing the yaw error of the average time having one or more time ranges according to the wind speed with the turbine stop reference value; And And stopping the wind turbine system if the yaw error of the average time having one or more time ranges corresponding to the wind speed is greater than the turbine stop reference value. The method of claim 1, When the wind power generator is below the rated output, the yaw error of the average time having one or more time ranges according to the wind speed can be replaced by the yaw error according to the generator rotation speed measured by the generator encoder. Control method for. The method of claim 1, When the wind turbine is output above the rated speed, the yaw error of the average time having one or more time ranges according to the wind speed can be replaced by the yaw error according to the pitch angle measured by the pitch angle encoder. Control method. The method according to any one of claims 1 to 3, The turbine stop reference value is a control method for reducing the load of the wind turbine, characterized in that the yaw error of the average time having one or more time ranges set in advance according to any one of the wind speed, generator rotation speed and pitch angle.

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