独立输入并联输出双有源全桥DC-DC变换器无电流传感器均流控制

Sensorless Current Sharing Control Strategy of Independent-input-parallel-output Dual-active-bridge Converters

针对电力电子变压器(power electronic transformer,PET)中的独立输入并联输出双有源全桥(dual-active-bridge,DAB)DC-DC变换器的功率平衡问题,基于双重移相控制(dual phase shift,DPS)提出一种无电流传感器均流控制策略,可保证系统各相DAB模块在参数不匹配或输入电压幅值不相等时能实现传输功率的自动平衡。该方法通过扰动实现系统参数的自动估算,并完成各相并联输出模块的逐级自动均流,从而实现各DAB并联模块的功率平衡控制;相比传统的单移相均流控制方法,提高了变换器运行效率的同时简化了系统电路降低成本。以两相独立输入并联输出系统为例,搭建10kW实验平台进行稳态和暂态实验,验证所提出控制方法的可行性和优越性。

Based on the problems of power balance of the independent input parallel output dual-active-bridge(DAB)converter in the power electronic transformer(PET),a dual phase shift(DPS)-based sensorless current sharing control strategy was proposed such that each module of the system can achieve transmission power automatically balance when the parameters of the modules in the targeted system do not match or its input voltage amplitudes are not equal.The method realizes the automatic estimation of the system parameters by using the scheme of disturbances,which completes automatic current sharing of the parallel output modules of each phase,thereby realizing the power balance control of each module,improving the efficiency of converter,greatly simplifying the system circuit and highly reducing the cost than traditional strategy.Finally,a 10kW experimental platform for a two-phase independent input parallel output system was built and the steady and transient experimental results verified the feasibility and significant advantage of the proposed control strategy.