To solve these problems,a new method,soft switch of voltage,was proposed in this paper.

Analysis of unusual situation of the voltage switching circuit;

Research of voltage switching in typical network structure of digital substation

Discussion on the design of micro-voltage switching function in the double busbar

Analysis and solution of voltage switch plug-burning problem

For the existing problem of the secondary voltage switch of duplicate bus voltage transformers,this paper firstly analyzes several situations of fuse blowing of voltage transformers and breakage criterion using microprocessor-based protection,and then concludes some measures to prevent mistake action causing secondary circuit losing voltage.

In the FB-ZVS-PWM converter, a saturable resonant inductor is used, which reduces the losses of the accessory circuit energy and effective duty cycle, and the load range of the Zero-Voltage-Transition (ZVT) is extended.

After investigating the manual of voltage switcher and the map of bus relay protection equipment, one fault is found that the "switch relays relay on at the same time" alarm can’t be send out when I bus and II bus seconda.