Research On Communication Technology Based On Residual Current Protection Device

Residual current protective device is widely used in low voltage distribution networkof AC as an important device for electrical safety. In the conventional work mode of powergrid, maintainer in power sector can not know about the reason of electrical fault timelywhen electrical fault occurred in power line. The reliability and continuity of power supplyis affected by the delay of fault handling. Therefore, It has important significance to carryout communication technology of residual current protection device.The communication terminal is designed to communicate with residual currentprotection device by accessing to a large amount of document. Communication terminalconnects with residual current protection device and polls the information of residualcurrent protection device one by one through the485bus. In order to ensure that theinformation of electrical fault is known by maintainer timely, communication terminal notonly displays the information of electrical fault, but also sends message to maintainer onceelectrical fault is occured in power line which is protected by the residual current protectivedevice. To avoid significant losses happened, maintainer can also cut off the fault bycontrolling the circuit breaker through communication terminal.Firstly, the characteristics of technology of wireless communication and485bus isanalyzed in this paper, and the theoretical basis of communication terminal is introduced.Secondly, the hardware circuit of communication terminal is designed aroundmicrocontroller LPC2106F which is included in the family of ARM7. The hardware circuitincludes circuit of SMS transceiver and circuit of communication of485bus. Thirdly,In this paper, the application features of wireless communication and485bustechnology is analyzed, and the theoretical basis of communication terminal design isintroduced. The hardware circuit of communication terminal is designed basing on ARM7microcontroller series master chip LPC2106F. A SMS transceiver circuit as well as a485bus communication circuit is included in the hardware circuit. The control program iswritten by C language for the whole communication terminal. Finally, it is achieved tomonitor and control the status of residual current protection device by testing the functionof communication terminal.