一种无均流外环并联DC-DC变换器的设计

Design of a Parallel DC-DC Converter Without Current Sharing Loop

设计了一种无均流外环并联DC-DC变换器,采用平均电流模式控制,通过控制最大编程电感电流,实现并联变换器的精确均流。采用小信号模型分析了并联变换器的均流误差和稳定性,电路实现了稳定的电流特性和快速的瞬态响应,具有优良的负载电流调节能力。仿真结果表明,该电路的均流误差在8‰以下,并联变换器在重载和轻载之间跳变时,1.5 ms内可恢复均流平衡,新插入变换器在0.7 ms时刻可重新建立均流平衡。

A parallel DC-DC converter without current sharing outer loop was designed. The average current mode was adopted to control the maximum programmed inductor current to achieve accurate current sharing of the parallel converter. The small signal model was used to analyze the current-sharing error and stability of the parallel converter. The circuit had stable current characteristics and fast transient response. An excellent load current regulation ability were achieved. The simulation results showed that the current sharing error was below 8 ‰. The current-sharing balance could be restored in 1.5 ms when the parallel converter had a load jump between heavy and light load, and could be re-established in 0.7 ms if a new converter was inserted.