A Co-ordinated Ride Through Capability and Power Quality Enhancement Scheme for Grid Tied PMSG Based Wind Energy

Abstract

The quality of injected current into the grid and low voltage ride-through capability (LVRT) for a grid tied PMSG wind energy is essential for grid operators. Under unbalanced fault conditions and grid-distorted conditions, the negative sequence current injects into the power electronic converter and leads to the wind turbine’s disconnection. However, as per the latest grid codes, wind turbines must not disconnect from the grid system. The power electronic converter on the generator side completely decoupled from disturbances on-grid side. Therefore, the effect of unbalanced and grid distorted current has less effect on machine side converter. However, the grid side converter is greatly affected since it is directly coupled to an external grid. The negative sequence grid voltage under unbalanced and distorted grid conditions introduces an unbalanced grid current, which results in fluctuations in dc-link voltage, rotor speed, torque active, and reactive power. Therefore, this paper suggests a Proportional Resonant (PR) controller for grid side inverter of PMSG to enhance the ride-through capability and the quality of injected grid current under adverse grid faults. The novelty of the proposed paper is to develop the PR controller with harmonic compensator which can improve the ride through capability and alleviate power quality issues. The usefulness of the proposed scheme is validated by comparing it with a typical PI control scheme