Research On Energy Storage Device And Control System Of Vacuum Circuit Breaker Motor Operating Mechanism

In order to improve the performance of the vacuum circuit breaker motor operating mechanism,reduce the collision loss and bounce time of moving contact during closing,and charge the storage capacitor,this thesis takes 126 kV vacuum circuit breaker motor operating mechanism as the research object to design the vacuum circuit breaker motor operating mechanism energy storage device and control system.The main contents are as follows:(1)This thesis researches the movement process of the opening and closing of the circuit breaker,analyzes and calculates the movement characteristics of the vacuum circuit breaker motor operating mechanism,including the opening and closing load torque,the speed,the stroke and the closing energy,thus obtaining the circuit breaker motor operation mechanism load torque curve,speed conversion curve,moving contact stroke curve and closing energy1500 J in the process of opening and closing.(2)Aiming at the bounce problem and collision loss problem of the moving contact during the circuit breaker closing process,the segmented fixed duty cycle control strategy is proposed,the four PWM control schemes are designed,The simulation experiment of closing section of circuit breaker shows that when the circuit breaker adopts scheme 3 for closing control,the starting time of the motor control mechanism is short,and the moving contact has the low kinetic energy,and the output torque can be increased during the overtravel stage to suppress the bounce of the moving contact.So the scheme 3 is the best scheme of closing regulation.According to the requirements of the circuit breaker closing process for the supply voltage range of 150V-400 V,the phase-shifted full-bridge energy storage converter is researched and designed,and the componets parameters of the converter are calculated by theoretical calculation,and the simulation system of the energy storage device is established.The simulation researchs show that the converter can ouput 400 V working voltage,which meets the energy storage design requirements,and the power tube has realized zero-voltage soft switching function.(3)In order to prove that the energy storage device and control system researched and designed in this thesis can meet the requirements of circuit breaker closing action,the experimental platforms are built,the energy storage experiments and the circuit breaker closing segmented control experiments are carried out.In the energy storage experiments,the converter can output 148V-416 V continuously adjustable supply voltage,and the voltage is stable,whichmeets the requirements of control system for power supply voltage,and the terminal voltage is only 40 V before the power tube is turned on.So the designed soft switch energy storage converter improves the working efficiency compare with the hard switch converter.In the circuit breaker closing control experiments,the starting time of the motor operating mechanism of scheme 3 is only 3ms,which is 3ms faster than that of scheme 4,although the closing time is4 ms and 2ms slower than that of scheme 1 and scheme 2,but the mechanical collision loss of the moving contact is lower,and no contact bounce occurred.So scheme 3 is the most suitable closing control scheme for the circuit breaker,verifying the simulation analysis results.It is proved that the control system designed by the segmented control theory can achieve segmented control to the output torque of the drive motor and the contact movement speed during the closing operation of the vacuum circuit breaker,can effectively reduce the contact collision and bounce time,and improves the closing performance.