Research On Control System Of Motor Operating Mechanism Of High Voltage Circuit Breaker

For the purpose of improving the control property and responsiveness of the motor operating mechanism of the 126 k V vacuum circuit breaker,this article develops research on the force characteristics of the transmission mechanism,the hardware and software design of the control system,segment control strategy of the circuit breaker and opening and closing characteristic experiment of the circuit breaker.The principal research content of the article is as below:(1)Study the motion characteristics of the motor operating mechanism.In connection with the technological index and fundamental structure of the motor operating mechanism,the force circumstances of the drive mechanism are analyzed.And obtain the relationship between the motor rotation angle and the contact stroke.Analyze the force of each section in the process of closing,fit the load force curve of the motor,and finally count the power performance of the closing.In connection with the mathematical connection of the motor,a system simulation model is established.Analysis of the winding current curve,torque curve and motor speed curve of the motor control system simulation model verifies the rationality of the motor control system design.(2)Design the control device of the operating mechanism.In connection with the characteristics of the working time of the circuit breaker motor operating mechanism,on the hardware circuit,the signal acquisition and conditioning circuit,communication unit,rectifier unit,inverter unit and isolation drive unit are designed with DSP28335 as the core processor.For the purpose of improving the starting performance and rejoin ability of the motor,the segmented control theory of the circuit breaker motor operating mechanism is researched.Besides,the boost converter is used as switched capacitor circuit.By changing the connection mode of the capacitor,the multi-fold boost of the energy storage unit is researched,and the movement process of the moving contact is controlled in sections.The signal acquisition and conditioning unit is integrated into the control circuit board,and the board layer structure is designed for anti-interference in the process of devising and welding the control circuit board.In the software procedure,the angular displacement signal detection program,main control program,and capacitance voltage detection program are designed.(3)Carry out the opening and closing test of the circuit breaker motor operating mechanism under different operating voltage conditions.Using switched capacitor circuit to carry out circuit breaker closing characteristic experiment under 200 V condition.The motor start delay time is reduced by 6.2ms,the total closing time is shortened by 28.5ms,and the average closing speed is increased by 0.67m/s.Using switched capacitor circuit to carry out circuit breaker opening characteristic experiment under 150 V condition.The total opening time is shortened by 23.9ms,and the opening speed is increased by 1.67m/s.The result indicates that the connection method of the capacitor is changed to charge and discharge.It can realize the multi-fold boost of the capacitor and the movement process of moving contact can be controlled by sections.The result proves the design of the control system is reasonable.