Design and Analysis of Improved Indirect Matrix Converter Supplying Power to Rotor of DFIG for Bi-directional Power Flow

Abstract

This paper proposes an improved switching strategy to control both input and output stages of a three-phase Indirect Matrix Converter (IMC). In improved switching, the input stage uses largest positive phase to phase voltage at each instant to produce maximum DC voltage with low ripple, and hence, the switching losses and the IMC output voltage distortions are reduced compared to Conventional Indirect Matrix Converter. Also, the fundamental input current of IMC with improved control is at unity power factor (UPF) for all operating conditions. The main advantage of IMC with constant input voltage and frequency is to supply power to multiple loads at different voltages and frequencies at the output stages. In this paper, the performance of improved IMC with two output stages, where output stage-2 is supplying power to static load at 45 Hz and output stage-1 is fed to rotor of doubly fed induction machine (DFIM) for bi-directional power flow is analyzed. The hardware setup for the proposed IMC is implemented in the laboratory and the experimental results are compared with those from simulation analysis.