Performance Evaluation of Variable Structure and Linear Control Strategies for Grid Connected PMSG Wind Energy System under Different Operating Conditions

Abstract

As the penetration of the Wind Energy Generation System (WEGS) into the modern power systems is extensively increased, an efficient control strategy of a WEGS plays an essential role in wind power utilization. This study presents Sliding Mode Control (SMC) design for the Variable Speed Wind Farm Systems (VS-WFS) based on Permanent Magnet Synchronous Generator (PMSG) and interconnected to the electric network. The proposed control laws are used to regulate both grid-side and generator converters. The generator side converters are used to track the maximum wind power. The function of the grid side inverter is to transfer the total extracted wind power from DC-link to the electric network and regulate the DC-link voltage. A SMC scheme is developed in the sense of Lyapunov stability theorem for the VS-WFS. Besides, the effectiveness of the proposed SMC scheme is demonstrated by comparison with a traditional Proportional Integral (PI) control strategy for fault conditions as well as for normal working conditions. Simulation results with Matlab/Simulink environment are presented to support the theoretical considerations demonstrating the potential contributions of both control strategies. The proposed SMC scheme can provide excellent control performance than the traditional PI strategy.