Centralized Active Power Control (CAPC) of PMSG Wind Power Plant for Normal and Frequency Contingency operation

Abstract

Wind power plants with Permanent Magnet Synchronous Generators (PMSG) employ full scale back to back converter that totally isolates the rotating system of the wind power plant from the electrical network. Therefore, there is no inertial contribution from wind power plant for primary frequency regulation. While the produced power of a WPGS is based on wind speed operating regimes, this power can be transiently increased with proper control action of the power electronics converter on the generator side. It is essential to design a centralized controller that manages the wind output power during normal operation mode, and that can be switched to the frequency contingency mode to support the network frequency. For normal operation mode, this paper proposes an adjustable controller with a dual objective of energy maximization and loading exertion minimization. For frequency contingency mode a transient active power control algorithm is proposed in order to imitate the response of a conventional synchronous generator. This algorithm uses an additional dual torque controller with one loop for the emulated inertia, and the other for the droop control. Simulations using MATLAB/Simulink were performed under different wind speeds, taking account of the wind aerodynamics to prove the efficacy of the suggested controllers.