分布式供电系统中负载变换器的输入阻抗分析

直流分布式供电系统由多个子系统组合而成，子系统之间的相互作用容易导致系统稳定程度和动态性能降低，甚至于不稳定。通常，恒功率负载具有的负阻抗输入特性是导致级联系统不稳定的主要原因。该文针对直流变换器在恒功率负载的情况下，以分布式供电系统中负载变换器的输入阻抗作为标准化研究的对象。该文以分布式供电系统中常见的同步整流Buck变换器为例，详细分析了变换器的输入阻抗随功率等级、开关频率和控制方式变化时的规律。并进一步通过实验验证了理论分析的正确性。实验结果为将来制定出Buck类DC-DC模块的输入阻抗的标准打下基础。

Input Impedance Analysis of Load Converters in the Distributed Power System

The dc distributed power system is often composed of several sub-systems. The interaction between the sub-systems is likely to deterioate the stability and dynaimcal performace of the whole power system, even making the system unstable. The characteristic of the negative input impedance is the main reason reponsible for such unstability. This paper selects the input impedance of the load converter, which is loaded with the constant power, as objects of standardization. The characteristics of the input impedance of the synchronous buck converter are analyzed in detail. The influence of three factors including the output power rating, the switching frequency and the control-mode on the input impedance are verified by experimental results. Experimental results lay a foundation for the standarization of the input impedance.