Wide Operating Range Bidirectional Impedance Control Network-based AC-DC Converter with Reactive Power Control

This paper introduces a generalized control strategy for reactive power control of a high-performance bidirectional Impedance Control Network (ICN)-based AC-DC converter. This bidirectional ICN converter comprises a power combining and power splitting network, facilitating high-performance across wide voltage ranges, in forward and reverse operational modes respectively. A comprehensive phase-shift control strategy is proposed to enable bidirectional power flow and reactive power control. An auxiliary zero voltage switching (ZVS) inductor, in conjunction with the phase-shift control, is employed to achieve soft-switching. A design methodology to select optimal values for the transformer turns ratio, the ICN differential reactance, and the auxiliary ZVS inductor is also presented. The proposed control strategy is validated using a 1.7 kVA, universal input, 200-500 V output bidirectional ICN-based AC-DC converter. Experimental results demonstrate the operation of the converter with unity and lagging power factor.