分析了建站较早的变电站直流系统改造的必要性和改造后所取得的效果,介绍了智能高频开关电源系统的性能特点及其各部分的作用和在改造过程中的改进情况。 The necessity of retrofitting the DC system of substation and the effect after the retrofit are analyzed. The performance characteristics of intelligent high-frequency switching power supply system, the function of each part and the improvement in the process of retrofitting are introduced.