A fast simulation model of PMSG with asymmetric control during an asymmetric grid fault

This paper presents a fast simulation method of PMSG, which adopts positive and negative sequence current separate control strategy during an asymmetric grid fault. Based on analysis of fault characteristics, the asymmetric control strategy is developed in PSCAD, aiming to alleviate the adverse effects on converter and grid during an asymmetric grid fault. Separate positive and negative sequence current and lock the phase respectively with SPLL method, then control each component in a closed loop by means of feedback decoupling, thus restraining ripple of DC bus voltage and second harmonic are realized. Furthermore, a simplified method based on remaining control and principle of energy balance is proposed. Simulation shows the rapidity and validity of the method, providing theoretical support for equivalent modeling of large-scaled direct-drive wind farm.