输入并联输出串联变换器系统的控制策略

将多个直流变换器模块在输入侧并联和输出侧串联,得到输入并联输出串联直流变换器,它可以降低开关管的电流应力和输出整流二极管的电压应力,适用于高输出电压、大功率的场合.为了保证该变换器的可靠工作,必须确保各模块的输出电压均衡.本文从能量守恒的角度出发,揭示了该变换器中各模块的输出均压和输入均流之间的关系,指出可以直接控制各模块的输出电压以使它们均衡,也可以采用输入均流控制来实现输出均压.提出一种新的输出均压的控制方法,它对系统输出电压控制闭环没有影响.同时采用交错控制,可以有效减小输入滤波电容和输出电容.论文最后给出了仿真和实验结果,验证了该方法的有效性.

Control Strategy for Input-Parallel Output-Series Converter Systems

Input-parallel and output-series (IPOS) converter systems, which is constructed from connecting multiple dc-dc converter modules in parallel at the input side and in series at the output side, can reduce the current stress of all switches and the voltage stress of all the output rectifiers, so they are very suitable for the high output voltage and high power DC-DC conversion application. In order to make the IPOS systems work normally, the output voltage sharing (OVS) of the modules should be ensured. By analysis of the relationship between the OVS and the input current sharing (ICS) in term of power conservation of each module, it is concluded that direct control to achieve ICS also can ensure OVS. A control strategy for the OVS which has no influence on the system output voltage is proposed. The interleaving technique is introduced to reduce the input capacitors and output filter capacitors. The simulation and experimental results are presented to verify the effectiveness of the proposed method.