Three-phase reactive power control using one-cycle controller for wind energy conversion systems

Abstract

This paper presents a new power factor correction scheme for a three phase wind energy conversion systems (WECSs). The proposed scheme provides power factor correction (PFC) with respect to the back-EMF of a permanent magnet synchronous generator (PMSG) instead of the terminal voltage. Since there exists a series impedance between the back-EMF and terminal voltage, performing PFC with respect to the terminal voltage leads to the additional reactive power generated by the back EMF. This additional reactive power degrades the capacity of the generator. In this paper, a novel three-phase reactive power control technique based on the one-cycle control scheme is presented in order to eliminate the need for additional reactive power. In the proposed technique, the terminal voltage and current of each phase are measured and the optimal power factor is regulated at the generator's terminals. The optimal reactive power is determined in the proposed control scheme by introducing a fictitious reactive current, derived from the input voltage, in the control law. The simulation and experimental results show the optimal performance of the proposed technique in terms of reactive power.