Abstract:Electric vehicle has become one of the main ways of environmental protection travel. As a power electronic transformation carrier connecting power grid and battery, Charging pile is an important research direction to reduce the influence of harmonics on power grid and charging pile itself. In order to reduce the voltage stress of switching devices and improve the efficiency and practicability of charging pile power conversion, a novel zero voltage zero current pulse width modulation (ZVZCS PWM) three level (TL) charging pile converter is adopted. Compared with the similar ZVZCS PWM TL converter, it reduces the use of magnetic devices, reduces the difficulty of design, improves the efficiency and reliability of the converter. In this paper, the working principle of the new ZVZCS PWM TL converter and the equivalent circuit structure in different time periods are analyzed in detail. The input and output characteristics of the circuit are deduced, and the conditions and strategies for realizing soft switching are given. The small signal model, closed loop block diagram and transfer function of TL ZVZCS PWM converter are derived. Based on the above model, the compensation design of the system is made, so that the system has good steady-state and transient functions. Simulation and experiment are carried out to verify the feasibility and effectiveness of the scheme.