SRF theory for voltage and frequency control of IAG based wind power generation

Abstract

This paper deals with the control of voltage and frequency of an autonomous wind power generation based on isolated asynchronous generator (IAG) feeding three-phase four-wire loads. The proposed control scheme is using the synchronous reference frame (SRF) theory based current detection. The proposed voltage and frequency controller (VFC) consists of a three leg voltage source converter (VSC) with a battery at its dc bus and a zig-zag transformer to provide a neutral terminal for three phase four wire loads. The mid-point of each leg of VSC is connected to three phase of incoming IAG supply through interfacing inductors. The proposed VFC is having bi-directional flow capability of active and reactive powers by virtue of that it regulates the system voltage and frequency. The VFC is capable of fulfilling the demand of reactive power of an asynchronous generator along with the function of load leveling, harmonic elimination, voltage regulation and load balancing. The complete generator system is modeled and simulated in the MATLAB using the Simulink and the sim power system (SPS) toolboxes. The simulated results are presented to demonstrate the capabilities of the proposed VFC for IAG in wind power generation.