Recently, from the good news released by national intellectual property bureau that Ma An Mountain Power Supply Company has developed “double-busbar PT voltage switching device” that has passed the examination of national intellectual property bureau and got the practical patent authorization.

In the current transformer with main connective line of double busbar, the traditional switching of voltage calculation is realized via the automatic switching of magnetic electrical reply which has high percentage of malfunction and there has no remedy when malfunction occurs. The correction for electrical reply shall take much time and the malfunction could not easily be found, and six power calculators could be laid in one screen. With this concern, the technical staff has made conversion towards the voltage calculation switching device by automatic, microcomputer and modularization processing to create the new voltage calculation switching device. This kind of device is directly used in the voltage calculation of two way line loop on power supply transformer which shall overcome the solve the voltage calculation switching problem and reduce the screen box of transformer with many line loops, at the same time, the maintenance work has greatly eased. The signals for direct current breaks and voltage loss shall be output and each switching voltage and operation state shall be indicated with light signals which are of great help for the work staff supervision.