Design Of Breaker Intelligent Unit For Traction Substation

With the promotion of digital substation technology, the application of digital substation in power system has become more widely, and traction substation digitization has become an inevitable trend. At present, the domestic has begun to carry out the R&D of digital traction substation system, including the R&D of breaker intelligent unit. By far, there is no mature product introduction. There is an urgent need to develop breaker intelligent unit for the digital traction substation, and in such a background, this paper was proposed. This paper analyzed the function of breaker intelligent unit in digital traction substation, and gave the principle structure of the breaker intelligent unit, and then wrote the corresponding software according to the function of intelligent unit, the contents that need to be monitored by the breaker was analyzed, this paper verified the control functions of breaker intelligent unit on the device.In this paper, breaker intelligent unit of traction substation was described in detail. For the online monitoring function of intelligent unit, the contents that need to be monitored by the breaker was analyzed, and realistic online monitoring scheme based on existing conditions was given. For typical traction substation, because breaker has different control function, this paper analyzed the control objects of the breaker intelligent unit, and gave the distribution scheme of intelligent unit. According to the characteristics of the typical traction substation the function of the intelligent unit needed was discussed, and according to the function configuration the main principles and structure of intelligent unit were given. Finally, the switch on-off principle of the intelligent unit in GOOSE message was given.About the characteristics of digital substation and the GOOSE communication function of intelligent unit, this paper carried out the analysis and explanation in detail. Functions of the traction substation breaker intelligent unit mianly include:receiving and parsing the GOOSE commands sent by the protection, measurement and control devices about the switch on-off, blocking and reclosing; driving the output relay to finish the the corresponding control functions, monitoring the state of switchgear and uploading the signal of the switchgear position status through the GOOSE message in real-time et.al. Then, this paper completed the software design of the breaker intelligent unit under the VxWorks operating system. In Vx Works, these events were finished through the real-time task, such as the GOOSE message sending and receiving, reading the input status and finishing the output signal, and semaphores was communicated between these tasks. Different tasks have different priorities to ensure that the important message to be handled first.Finally, this paper carried out the function validation test of the intelligent unit software on the device. Intelligent unit received the GOOSE message of protection device accurately through the network, and parsed GOOSE message to drive output relay to control the switch on-off of the analog breaker, and at the same time uploaded the detection result of the breaker position status signal. Test results demonstrated the real-time and correctness of the intelligent unit software.