Integrated AC to AC Converters for Single-phase Input to Two-phase Output Motor Drives

The single-phase to two-phase converters have become attractive for low-power motor drives due to the full electromagnetic isolation between phases of two-phase motors. One of the commonly used topologies is the ac/dc/ac pulse width modulation (PWM) converter which contains twelve active power semiconductor switches and a common dc link. To minimize the system cost and size for low power applications, an integrated ac/ac converter with a single-phase input and a two-phase output which reduces the switch count to six is proposed in this paper. Additionally, modulation scheme and filters for the proposed converter are developed and modeled in details. In this paper a systematic comparison among the conventional ac/dc/ac converters, matrix converters, and the proposed integrated ac to ac converters for single-phase input to two-phase output motor drives applications is performed in terms of the output voltage/current capability, total harmonics distortion (THD), and system cost. Furthermore, closed-loop speed controllers are developed for the three topologies, and the maximum operation range and output phase currents are investigated. Simulation and experimental results validated the effectiveness of the developed converters and control strategies.