Research On Permanent Magnet Motor Operating Mechanism In126kV High Voltage Vacuum Circuit Breaker

As the construction of smart grid and demand of intelligent switch equipment, thepermanent magnet swing angle torque motor (PMSATM) operating mechanism is selectedand presented in order to improve the control performance and operating reliability of highvoltage circuit breaker in this paper. The operating mechanism can achieve the openingand closing operation for circuit breaker by using the PMSATM. It has many function suchas fast response speed, optimize the itinerary curve, and easy to realize the communication,real-time monitoring and fault diagnosis etc. Making the126kV high voltage vacuumcircuit breaker as the research object, the research are carried out from the opening andclosing moving characteristics of the circuit breaker, the design of PMSATM, segmentadjustment method in moving process, the dynamic performance testing and the practicalengineering applications.The main contents of the thesis can be concluded as follow:（1）The motion and dynamical coordination characteristics of vacuum circuit breakerand motor operating mechanism are researched. The virtual prototype technology isemployed to establish the dynamics model of vacuum circuit breaker motor operatingmechanism, and it verifies the correctness of the model by comparing with the measureddata. The range of opening and closing motion for contact are put forward, and the strokemathematical model of insulating pole are built in the different opening and closing speedby using the method of section function and virtual prototype, which design the differentspeed in different stage based on mechanical characteristic requeirement of126kV highvoltage vacuum circuit breakers. The structure, moving rule and constraint relationshipbetween the different parts are analized, and given the angle range, equivalent moment ofinertia and load torque characteristics of driving motor in opening and closing operation.（2）Base on the theory of permanent magnet motor design and transient finiteelement, the structure design, selection of parameters and calculating model of dynamicperformance of PMSATM are founded. Employing the peak torque, peak rotational speed, limited angle and short-time working state as the design target, the PMSATM is design byusing the method that combing the structure and main parameters design and dynamicperformance calculation. The structure size of stator and rotor, the excitation mode of rotor,torque constant, EMF constant, number of pole pairs and time constant are discussed andgiven out the design value. And the flied-road-motion coupling finite element models ofPMSATM are established through the analysis of topology circuit structure and blockcircuit equation in different operation interval under the opening operation. The angle andelectro-magnetic torque characteristics of driving motor are carried out under the differentparameters such as the length to diameter ratio, turns and line width ratio, permanentmagnet thickness and pole arc coefficient., The simulation model is correct throughcomparing with the performance testing results, and the dynamic parameters of drivingmotor meet with the average speed requirement of circuit breaker under the best structureand winding parameters.（3）The segment adjustment realization method of PMSATM are researched inopening and closing operating process. Considering the change of rotation speed indifferent angle stage for driving motor, the segment voltage starting motor, variable air-gapstructure motor and asymmetric winding structure motor are proposed from the operationvoltage, excitation structure and armature winding. The schemes of three type motor arecarried out and the dynamic performances meet with the requirement of circuit breakerthrough comparing with the testing results. Comparing with the variable air-gap structuremotor and asymmetric winding structure motor, the segment voltage starting motor havegood speed characteristics in the different stage, and it can provide a better basis for theservo control in the next step.（4）The testing system of vacuum circuit breaker and permanent magnet motor areestablished, and the prototype of PMSATM and controller are manufactured. The dynamiccharacteristics of vacuum circuit breaker and experimental prototype are measured inno-load condition, and analyzed the influence on the stroke of contact under the differentpower supply voltage and repetitive operation in the same condition. Considering thecompliant interrupting and closing characteristics of permanent magnet swing angle torquemotor, the adjustment PWM output duty cycle of driving controller is adapted to adjust thedifferent rotational speed in the different angle stage. Compared with the measuring resultsand the calculation results, it is indicated that the accurately and applicability of permanent magnet swing angle torque motor theory design method and the calculation of dynamicperformance.