A simple predictive direct current control for grid side converter of DFIG under ideal and non-ideal supply voltage

Abstract

This paper presents a current control strategy for grid side converter (GSC) of DFIG. In this method, voltage vector sequences are predicted to control the current of this converter in synchronous frame. In this method, the converter voltage sector is confirmed according to the grid voltage phase sector and rectifier or inverter mode of the converter. Four voltage vectors are predicted at each converter voltage sector and each vector is applied two times in a period to have a constant switching frequency and low total harmonic distortion (THD). Under unbalanced and non-sinusoidal grid voltage conditions, without extra controller, the proposed technique injects or absorbs sinusoidal current while the switching frequency is constant. A three phase grid connected converter is used to analyze the behavior of proposed control technique under ideal and non-ideal supply voltage. The simulation is carried out in MATLAB/SIMULINK environment.