This application is the national phase of International Application No. PCT/CN2018/086175, titled “METHOD AND APPARATUS FOR CONTROLLING WIND TURBINE POWER”, filed on May 09, 2018, which claims the priority to Chinese Patent Application No. 201711450275.5, titled “METHOD AND APPARATUS FOR CONTROLLING WIND TURBINE POWER”, filed on Dec. 27, 2017 with the China National Intellectual Property Agency (CNIPA), which is incorporated herein by reference in its entireties.

FIELD

The present disclosure relates to the technical field of control, electrical circuit, and wind power generation, and in particular, to a method and an apparatus for controlling wind turbine power.

BACKGROUND

A dynamic process of wind power generation is converting kinetic energy of the wind into mechanical energy, and then converting the mechanical energy into electric energy. The wind power generation mainly uses the wind power to drive windmill blades to rotate, and then increases a speed of rotation via a speed increaser to make a generator generate electricity. Net grid-connected power of a wind turbine is active power outputted from the wind turbine to a low-voltage side of a box-type transformer. It removes mechanical losses, generator losses, converter losses, internal line losses of wind power, and unit self-consumed power of the wind turbine during wind power generation. Generally, target active power serves as an input of a wind turbine controller. Thereby, the wind turbine controller outputs a current-varying torque setpoint and a pitch angle setpoint, based on the target active power. Thus, the wind turbine can generate power according to the foregoing requirements. Due to an inadequate design of wind turbines at early stages, a deviation of position of a connection with the self-consumed power of the wind turbine, and a difference in design of the converter, measured active power outputted by the wind turbine may not be the net grid-connected power. In addition, there are many reasons for the deviation between the inputted target active power and the net grid-connected power of the wind turbine controller. For example, a loss of a full power converter is related to an ambient temperature. Even if there is the same reason for the deviation between the active power and the net grid-connected power, magnitude of the deviation is different in different situations. For example, loss coefficients from different seasons are inconsistent, and unit losses are also different. Thus, in a case that the active power is used as the input of the wind turbine controller, it requires multiplying the active power by a loss coefficient, thereby increasing or decreasing the current-varying torque setpoint and the pitch angle setpoint outputted by the wind turbine controller, so as to ensure that the net grid-connected power is equal to the target active power.

Generally, the loss coefficient is obtained by measurement, and needs to be set according to parameters that can cover all working conditions. The method described above results in a long period of loss coefficient measurement, and a complete loss coefficient needs data of at least full working conditions which include climate. Also, the parameters may not cover all working conditions. Since all wind farms have different conditions, it is not practical to measure the loss coefficient of each wind farm separately. Further, there may be influencing factors that are currently unknown. Adjusting the wind turbine parameters (especially the current-varying parameter) would have a large impact on the loss coefficient, and parameter optimization is necessary in most cases.

SUMMARY

The object of the present disclosure is to address at least one of the above technical issues, and in particular, address a deviation between target active power and a net grid-connected power inputted into a wind turbine controller due to various reasons, and address issues such as a long period of loss coefficient measurement and complex working conditions that influence parameters.

According to an aspect of the present disclosure, a method for controlling wind turbine power is provided, including: determining a compensation value for target active power based on a power difference between a net grid-connected power and the target active power; determining a setpoint value of active power based on the target active power and the compensation value; and performing a current-varying control and a pitch control based on the setpoint value of active power.

According to another aspect of the present disclosure, a device for controlling wind turbine power is provided, including: a first compensation value determining module, configured to determine a compensation value for target active power based on a power difference between a net grid-connected power and the target active power; an active power setpoint value determining module, configured to determine a setpoint value of active power based on the target active power and the compensation value; and a current-varying and pitch control module, configured to perform a current-varying control and a pitch control based on the setpoint value of active power.

According to yet another aspect of the present disclosure, a computer readable storage medium is provided, where the storage medium stores a computer program, and the computer program when executed by a processor implements steps of the method for controlling wind turbine power according to any one of the above technical solutions.

According to still another aspect of the present disclosure, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and operable on the processor, where the computer program when executed by a processor implements steps of the method for controlling wind turbine power according to any one of the above technical solutions.

Additional aspects and advantages of the present disclosure are hereinafter partially set forth in the following description, which are apparent from the following description or appreciated from practice of the present disclosure.

