SF6 extra high voltage (EHV) circuit breaker is crucial equipment in the electric network to control and protect the electric power systems, and its security and stability exert a direct influence on the stability of electric power systems. With the constant development of smart grid, it becomes urgent to develop the intelligent SF6 EHV circuit breaker. The previous research on SF6 EHV circuit breaker mostly concentrates on its parameter monitoring and its operation mechanisms at home and abroad. There are few studies on intelligentization of EHV circuit breaker. In addition, the operating EHV circuit breakers in China rarely have intelligent supervisory control systems which can monitor running state of circuit breakers. The thesis aims to realize intelligentization and supervisory control system of SF6 EHV circuit breakers, which can be divided into the following four parts. Firstly, the thesis presents and analyses the overall research situation of SF6 EHV circuit breakers at home and abroad. The SF6 EHV circuit breaker of type LW12-500 is taken as the research object. After a thorough analysis of its structure characteristics and the cause of failures, a research idea and an implementation method for intelligentization of SF6 EHV circuit breakers are presented. Secondly, the author designs a supervisory control system based on ARM embedded controller. The system uses oil pressure transmitter and SF6 pressure transmitters to gather the pressure of oil and SF6. Then a control strategy for oil pressure control and SF6 pressure supervision is presented in light of the control method of micro pressure switches. Besides, the system accomplishes a double-annular fiber CAN communication network used for connecting all the EHV circuit breakers in a substation, and the protocol of CAN application for the communication network is presented to ensure the communication stability between EHV circuit breakers and a remote computer. Thirdly, the author designs the monitor configuration for remote computer display and the history data management system for recording real-time operational parameters of an EHV circuit breaker. According to the actual situation of Hunyuan switching station, the author conducts an experiment to check the operation of intelligent supervisory control system and fiber CAN communication network. The history data recorded by the history data management system verifies the control strategy for oil pressure control and SF6 pressure supervis...
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