适用高压直流充电的多端口变换器及特性分析

Multi-port Converter for High Voltage DC Charging and Its Characteristic Analysis

提出并研究了一种适用于高压直流充电的多端口整流器和输出直流电压层叠结构的单相AC/DC变换器。为降低高压应用场合下传统Boost功率因数校正(PFC)变换器中器件的电压应力和开关损耗,在Boost变换器的基础上构建了两个直流输出端口并通过直流变压器实现两个端口的串联,且变换器中的多端口整流器用于同时控制输入电流和两个直流端口电压。分析了所提多端口单相AC/DC变换器工作特性及工作方式,基于电感两端伏秒平衡的控制方式,所提出的变换器可在不同模式间实现平滑切换,同时具有三电平特性及器件应力低、开关损耗小的特点。通过2 kW样机实验验证了所提出的变换器及其控制方式的正确性和有效性。

A single-phase AC/DC converter for high voltage DC charging based on multi-port rectifier and output direct current voltage stack structure is proposed and analyzed.In order to reduce the voltage stress and switching loss of the devices in the Boost power factor correction(PFC)converter in high voltage applications,two direct current output ports are built on the basis of the Boost converter and the two ports are connected in series through a direct current transformer.The multi-port rectifier in the converter is used to control the input current and the voltage of the two DC ports at the same time.Based on the control method of voltage-second balance between two inductors,the proposed converter can achieve smooth switching between different modes,and has the characteristics of three levels,low device stress and low switching loss.The correctness and effectiveness of the proposed converter and its control mode are verified by the experiment of a 2 kW prototype.