Rapid Power Curtailment Method Considering Power Imbalance of the Wind Power Generation System

Abstract

This paper proposes a rapid power curtailment method for a permanent magnet synchronous wind generation system to regulate the grid frequency in a weak grid. In a situation where rapid power curtailment is required, the conventional power curtailment method of the wind turbine can cause a power imbalance between the electrical energy and wind energy in the wind power generation system. It can cause severe damage to the generator because of overspeed in the wind turbine, which may require stopping power generation even though it can inject power into the grid. Cooperative control can be applied to resolve power imbalance during conventional power curtailment, which uses both the wind turbine’s pitch angle control and the machine-side converter’s current control. In other words, the pitch angle controller calculates the pitch angle for the active power output for the current wind speed conditions, and the machine-side converter calculates the current value for the active power output, so that the suddenly curtailed active power output of wind power generation can be achieved quickly and stably through cooperative control of pitch angle and converter current. The proposed method is simulated by PSCAD/EMTDC, and it is proven that the behavior characteristics of wind power generation for power curtailment are stable and well achieved.