Design and implementation of a single phase current-forced switching mode bilateral convertor

A single-phase switching mode bilateral convertor using current-forced hysteresis switching control is designed and successfully implemented. The power circuit configuration is simple, since only one full-bridge convertor is required, and the lock-out circuits are not necessary. Based on the proposed current-forced switching scheme, the bidirectional power flow is very easy to control and the switching voltage jumps and losses can be reduced. Moreover, the line current can be sinusoidally regulated with unity power factor in the rectifier mode, and the voltage waveform distortion can be kept small in the inverter mode by instantaneous voltage control. To perform the control system design, the transfer function models of the proposed convertor system in two operation modes are built up, and then a generalised systematic design method is proposed to find the parameters of the controllers according to the prescribed specifications. Some experimental results are provided to demonstrate the effectiveness of the proposed convertor.