Design And Application Of Coil Excitation Brushless Dc Motor Operating Mechanism For High Voltage Circuit Breaker

In order to eliminate the inherent defects existing in the permanent magnets of the permanent magnet motor operating mechanism for high voltage circuit breakers, and improve operational reliability of the circuit breakers to promote the development of intelligence, this paper has taken a 40.5kV high voltage circuit breaker as the research object to present coil excitation brushless DC motor(CEBLDCM) operating mechanism for high voltage circuit breaker. This paper have made an intensive study on motion process and load characteristics of motor operating mechanism, motor structure layout and working principle, design of structure parameters and electromagnetic characteristics of dynamic operation of the motor. Finally the design scheme of the C EBLDCM was dete rmined and a prototype was made to conduct the experiment. The main research contents of this paper are as follows:(1) Movement and load characteristics of motor operating mechanism were researched and motion analysis model of motor operating mechanism was established. Corresponding relationship between drive motor and circuit breaker lever was derived. The linear motion of circuit breaker was turned into whirling motion of motor. Torque characteristics of the motion load of circuit breaker converted to the axle of the drive motor was computed, and then got the angle range of the rotor, equivalent load torque and other parameters of motor.(2) The topology of C EBLDCM was researched; the combining scheme of rotor poles was formulated; the position layout and assembly methods of each motor structure were determined; the excitation winding conduction order of motor was proposed; the run mode of motor was clarified. In order to provide a theoretical basis for the des ign of the new drive motor, the working principle and the electromagnetic characteristics of the motor was analyzed from the aspect of magnetic circuit.(3) The design calculation scheme of each structure was proposed for the motor. Electromagnetic properties and motion characteristics of CEBLDCM and the impact of different pole arc, gap, the core, the structure of stator space, coil excitation and others on dynamic performance of the motor operating mechanism was analyzed according to the method of the combination of technical indicators and dynamic simulation of high- voltage circuit breakers. In order to satisfy high-voltage circuit breaker operating mechanism of opening and closing requirements, the structure parameters were adjusted and optimized and the final design CEBLDCM operating mechanism was determined, thus, it provides the basis for intelligent operation of high voltage circuit breakers.(4) CEBLDCM prototype was produced and an experimental platform for motor operating mechanism was built. The control system applied to CEBLDCM was designed. The power converter design for CEBLDCM was proposed and each detector selection, design and application methods for CEBLDCM determined. Finally, the basic data of motor meet the design requirement of operating mechanism in the experiment of no- load test. This paper laid a good foundation for the future of intelligent control and high- voltage circuit breaker operating and other experiments.