Coordinated optimization frequency control method for variable speed and pitch of wind turbines under load reduction

Abstract

The invention discloses a variable speed and pitch coordinated optimization frequency control method of a load-reduced wind turbine, comprising: load reduction control: calculating the load reduction rate of the wind turbine, thereby dividing the wind speed into a plurality of wind speed intervals, and according to different wind speed intervals and frequency modulation control Part of the results adopt different load reduction control strategies for wind turbines; frequency modulation control includes: parameter optimization and frequency control; when parameter optimization, the reference value of wind turbine speed and pitch angle is calculated based on the mechanical power of the wind turbine and the actual additional power , so as to realize the pitch angle control; during the frequency control, the reference value of the rotational speed calculated by parameter optimization and the actual additional power of the wind turbine are used to realize the output power control of the wind turbine, and the corresponding control results are also used in the load shedding control stage. This method enables the wind turbine to accurately determine the load shedding strategy and optimize the speed and pitch angle control at all wind speeds, so as to obtain a better frequency control effect.

Description

technical field [0001] The invention relates to the technical field of active power control of wind power generation, in particular to a method for controlling the coordinated optimization frequency of variable speed and pitch of a load-shedding wind turbine. Background technique [0002] In recent years, the penetration rate of wind power in the power system has been increasing. Compared with traditional synchronous generators, wind turbines are connected to the grid through power electronic devices and cannot respond to changes in system frequency. An increase in the proportion of wind power will reduce the system's inertial response and primary frequency regulation capability, and increase the demand for reserve capacity. In addition, wind turbines usually operate in the state of maximum power tracking (MPPT), and it is difficult to adjust the frequency of the system through power generation. In order to ensure the safe and stable operation of the power system, it is ne...

AI Technical Summary

Problems solved by technology

The key to realize the frequency control of the wind turbine is to coordinate the output power and mechanical power of the wind turbine, otherwise it will easily cause the unstable operation of the wind turbine or cause the secondary frequency to drop; however, there is no effective solution at present, resulting in poor frequency control effect

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