The Design Of Monitor IED For Catenary Isolating Switches

The catenary isolating switch is one of the important equipments in the electrified railway, used for traction power supply. It is used, in OCS, mainly for the fault isolation, subsection maintenance, and changing the way of power-supplying etc. In the big railway hub, there are a large number of catenary isolating switches distributed extensively, so it is necessary to monitor them.In this paper, the monitor IED for the catenary isolating switches, which is part of the traction substation automatization system as a device in bay level, actualizes the monitor function with the measurement and control device. The hardware and software of the monitor IED are designed in this paper, which can make IED act as the role of the data retransmission and monitoring the catenary isolating switches, in the traction substation.Firstly, the hardware design of the monitor IED is introduced, including the composition of the device’s networked hardware and the design of different function boards. Then, the software is designed by C language with clarity and popularity, based on the idea of modular structure, which can be developed and expanded easy. The Ethernet communication module, CAN-bus communication module, serial-port communication module and input/output function module are designed in the software. The IED uses the IEC60870-5-104communication protocol to communicate with monitoring center and uses the IEC60870-5-103communication protocol to communicate with the measurement-control device. Based on the study of IEC60870-5-104and IEC60870-5-103communication protocol, the communication modules based on the two communication protocol are accomplished.Finally, the communication protocol test is taken. The test results show that the IED in the traction substation automatization system can communicate with monitor center and the measurement-control device well, transform information from the communication protocol IEC60870-5-104to the communication protocol IEC60870-5-103and make the monitor function work well.