The Control Functions Design Of Centralized Protection Control System For Traction Substation

The secondary equipment of traction substation mainly applies the hierarchical distributed architecture, which is interval oriented and has independent function. Each unit is able to accomplish the data-measurement, protection and control function reliably and independently. However, the associated problems are the repeated hardware configuration, secondary wiring complexity, stand-alone information, high investment, cost and maintenance, lack of overall coordination and function optimization and so on. The centralized protection control system of traction substation is concentrated in a computer system to achieve the integration of protection and control and simplify the secondary wiring. This can also achieve the goalofreal-time data sharing to avoid repeated hardware configuration. It is of great importance to the study of protection of centralized traction substation and control system. Therefore, a design and study of this field is conducted in this paper.The control parts of the centralized protection control system of traction substation mainly include spare power automatic switching and switch control logic atresia. According to the characteristics of centralized protection control system, this paper investigated the four ways of working in terms of standby power source and standby transformer in the context of double-T substation. By doing so, design of functional programs of spare power automatic switching is accomplished. According to the method of substation wiring diagram export atresia formula and knowledge of graph theory, the design program of spacer layer of five anti-lockout was discussed thoroughly.According to the characteristics of the traction substation, actual operating conditions, and the function the protecting and controlling system planned to achieve, this paper made a hardware architecture design to the protection and control system of the centralized traction substation. Both SMV and GOOSE network formation was selected separately.100M Fiber Ethernet network was selected through the calculation of network traffic. The group-multicast switch supported priority technology and Virtual Local Area Network (VLAN) technology was also selected. Double star wiring was used in the process and station control level. After the analyzing of the hardware configuration of the system, a multi-processor architecture, good at dealing with network data, was selected to use for the centralized protection control unit.According to the function to be accomplished by the control part of the centralized protection control system of traction substation, rational division is finished in this paper. The centralized control software was developed based on Windows Operating System’s multi-threaded multi-tasking features. The receiving, sending and analyzing session of GOOSE transmission packet was investigated in depth and the design of five anti-lockout rule.The encoding, sending, receiving and decoding of GOOSE packet and spare power automatic switching packet were also accomplished in this paper. The simulation platform was successfully built.Through this simulation platform, the correctness of the GOOSE message’s transceiver module design was verified. The function of spare power automatics witching of centralized protection control system is also successfully evaluated.