Phase Selection Reclosing Control Of 10kv Permanent Magnet Vacuum Circuit Breaker

The automatic reclosing technology can greatly improve the power supply reliability of power system.However,when a permanent fault occurs,the circuit breaker reclosing will make the system and loads suffer an impact of fault current again,which may lead to the damage of power equipment and affect the power quality.As a result,the pulse reclosing technology based on phase selection control strategy arises at the historic moment.In this thesis,a control unit and a drive circuit are investigated for the permanent magnet(PM)actuator with short-time closed function,and the corresponding control strategy is formulated,based on which,a phase selection control system for10 k V PM vacuum circuit breaker is developed.Firstly,the topological structure and working characteristics of traditional PM actuator are introduced,hereby the working principle of short-time closed PM actuator is explored.The research status at home and abroad is subsequently analyzed from two aspects of circuit breaker phase selection control technology and reclosing technology.Then the circuit model of driving coil is established,and the variation characteristics of coil current are analyzed in terms of the control requirements analysis of the short-time closed PM actuator.Based on the principle of phase selection control,this thesis discusses the influence factors and application occasions of phase selection control technology.By combining the control logic of reclosing with phase selection control technology and selecting the appropriate data filtering algorithm for sampling data processing,the control strategy of phase selection short-time reclosing is established for the developed short-time closed PM actuator.On the basis of theoretical research,the software and hardware systems of the pulse reclosing circuit breaker are developed.The hardware system includes a system control module,a switch drive module and a data sampling module.All modules cooperate with each other to collect and process data information,send control instructions,drive the switch elements to open and close,and realize the drive control of the circuit breaker.The software system includes an underlying program embedded in DSP and a human-computer interface.The connection between software and hardware is established through SCI communication to realize the intelligent control of the developed PM actuator.The dynamic performance of 10 k V short-time reclosing circuit breaker is tested in laboratory,and the zero crossing detection and filtering effect of the control system are experimentally verified.The simulation experiment under low voltage environment is completed according to the phase selection short-time reclosing strategy.Finally,the phase selection short-time reclosing tests under different line faults are carried out under 10 k V high voltage condition provided by Suzhou Electrical Apparatus Science Academy,which verifies the correctness of control strategy and the reliability of control system.