Dynamic modelling and control of a step up/down switching-mode rectifier

The authors present the dynamic modelling and control of a switching-mode r ectifier (SMR) with step up/down voltage and power factor correction contro l. Depending on the output voltage level, this rectifier can be operated in buck or boost mode during each AC half cycle. It follows that this SMR pos sesses wide DC output voltage range, and it can be used as a battery charge r with large charging flexibility fbr a serially connected battery bank. Th e power circuit of the proposed rectifier is first analysed and designed. T hen its dynamic model is derived. Based on this, a current waveform control ler is designed, such that sinusoidal line current with low harmonics and n ear unity power factor is obtained. In addition, a charging controller is a lso designed for yielding good dynamic charging characteristics. After conf irming the validity of the designed rectifier by simulations, the circuit i mplementation is performed and some measured results are provided for furth er demonstrating its performance.