Control of a new stand-alone wind turbine-based variable speed permanent magnet synchronous generator using quasi-Z-source inverter

Abstract

In this paper a new variable speed permanent magnet synchronous generator (PMSG)-based stand-alone wind energy conversion system (SWECS) is proposed. The interface between the PMSG and the isolated load is accomplished by a quasi-Z-source inverter (qZSI) with battery storage system. The battery-assisted qZSI can balance the stochastic fluctuations of the wind power injected to the load and improve the voltage and frequency control. In addition to the battery storage, a dump load is used in the proposed SWECS to better maintain the active power balance and stability of the dc-link voltage during over-generation condition as well as sudden load changes. The proposed control system is able to provide an uninterrupted and reliable supply to sensitive loads under various power generation scenarios of the SWECS and sudden changes in the load demand. Moreover, the proposed controller provides maximum power point tracking (MPPT) which is essential for optimum operation of the SWECS. The validity of the proposed system is proved by simulation results carried out using MATLAB/ SIMULINK.