Simulation based performance analysis of high frequency improved power quality bidirectional multilevel AC-DC converters

This paper presents single and three phase topologies, employing power MOSFETs, of the bi-directional multilevel improved power quality ac-dc converter (IPQC) and explores the possibility of their use in high frequency applications using simulation software. The simulations are conducted for a fundamental frequency of 50 kHz. The current-forced control (CFC) strategy based waveshaping of line currents, enabling operation at any power factor in inversion and rectification modes, is investigated vis-a-vis the bi-directional multilevel converter. Performance analyses of the topologies suggest that the structure of the bi-directional multilevel ac-dc converter using cascaded inverters with separate dc sources is well suited for various renewable energy sources such as fuel cell, photovoltaic, and biomass; and justifies the research efforts directed towards adoption of the bi-directional multilevel IPQC ac-dc conversion for high frequency applications. The simulations results, including those pertaining to unity fundamental power factor; confirming the feasibility and effective performance of the proposed converter topologies and the efficacy of the CFC strategy, at high frequency, are presented.