The Development Of Supervisory Device For The DC System Of The Substation

The paper analyzed the features and present state of the DC(Direct Current) system of the substation,then designed a full-function and easy-control supervisory device for the DC system. In the device,a PC/1O4 CPU module(Inte!486DX4-100) was used as the central processing unit. And a 32 channel A/D board,a 24-IN/16-OUT Dl/DO board and an expanded serial port board was designed to structure the hardware system of the device. A 5.7 inch Touch-LCD was used as the Human-Machine Interface of the device. The supervisory device has a complete control to the Touch-LCD. If the LCD wasn t touched in several minutes,the device will turn off the LCD s backlight. Moreover,operator can regulate the screen s contrast by touching the LCD. The software system of the supervisory device consists of several independent function modules. Some modules cooperated with hardware system to collect,analyze and display the parameters of the DC system. Other modules fulfilled some functions:charger control,alarm history data,device parameter s setting. The software system has a complete-function control for the running of the DC system. The paper introduced the DNP3.0 protocol that was widely used in electric power system,and designed a communication module to exchange data with Control Center based on the DNP3.0 protocol. The on-field test and practical running showed that the device met the target expected. The device has stably run in practical field for three months.