Design and implement of voltage control circuit in DC energy storage unit of power quality compensator based on improved zero voltage transition PWM

Supplying power for DC energy storage unit of power quality compensator by rectifier will produce much harmonic and decrease power factor. Active power factor correction technology can resolve the problem, but it will bring much switching loss and put forward higher requirements to the frequency and stress of power device. It proposed soft switching power transformation technology to control switching device and presented a control strategy based on improved Boost zero voltage transition PWM converter and designed its circuit topology. The operation course of the circuit was researched and the switching state of power device was analyzed. The improved circuit made main switching device operate under zero voltage and auxiliary switching device work under zero current. Simulation results have verified the validity and feasibility of the strategy.