| In order to meet the needs of the intelligent development of switching equipment,improve the reliability of switching equipment.The breakdown mechanism of high voltage vacuum circuit breaker is studied,and the method of controlling the speed of the contact by the motor operating mechanism is used to control the breakdown in the movement process of the circuit breaker is proposed in this paper.The safety operating performance of circuit breaker is improved.In order to improve the safety performance of high voltage circuit breaker,the intelligent control technology and operating system to meet the requirement of the high voltage circuit breaker is designed in the paper.The following work is carried out:(1)The structure and operating characteristics of the motor operating mechanism are studied,and the equivalent parameters of the actuator are calculated to the side of the motor.Taking the drive motor as the research object,the starting process of the drive motor is analyzed.Based on the motor armature equation,torque equation and mechanical dynamic equation,the mathematical model of motor operating mechanism is established,the mathematical relationship between parameters is analyzed.The method by adjusting the winding voltage of drive motor to control motor speed is effective.The numerical simulation method is used to build the mathematical model of the drive motor,and the simulation research is carried out.The result prove the correctness of using the pulse width modulation technique to control the motor speed.(2)The breakdown mechanism of vacuum switch is studied,and the calculation equation of contact recovery voltage is derived.The relationship between withstand voltage and voltage recovery of contact as the breakdown criterion,the equation contact distance about the time is established,the contact speed is acquired in the rigid phase by derivativing function equation.Regarding the switched capacitor bank in the peng-liu transmission line as operating condition,the equivalent circuit parameters are calculated,based on the contact speed formula,the velocity curve of the contact is calculated in the rigid phase.Combined with the speed index of the high voltage circuit breaker and adjusting speed equation of the motor,the velocity curve of the overshoot phase stage and the buffer stage are obtained.The three stage speed curves are combined,and the preset speed curve is obtained.(3)The generalized predictive control algorithm is studied.According to the motor parameter equation,the relationship between the input voltage and the output speed is established.Based on Laplace transformation,the transfer function is calculated.The amplitude frequency response is analyzed to determine the sampling frequency.Combined with diophantine equation,the transfer function of the drive motor is discretized,and the prediction model of the drive motor is established.According to the feedback correction of the model output error,the two time performance index is used to optimize.The closed loop simulation of the generalized predictive control of the motor operating mechanism is carried out in this paper.Compared with the conventional PID control,the generalized predictive control can achieve better tracking speed,and the maximum velocity deviation is 0.026m/s.The hardware control system of the motor operating mechanism is studied,and the working principle of the hardware unit is analyzed,and the control circuit is drawn in the printed circuit board,and the welding and debugging of the control circuit is completed.On the basis of CCS development platform,the drive motor control program is written,the design and debugging of the program is completed.(4)On the basis of the experimental platform of 126 kV vacuum circuit breaker motor operating mechanism,the online experiment is carried out.The variable structure experiment circuit of storage capacitor is built,the discharge experiments of series structure storage capacitor and parallel structure storage capacitor of motor actuator is completed.The result proves that the storage capacitor can improve the motor operating mechanism operating performance charging in parallel charge series discharge.Based on the generalized predictive control strategy and the hardware circuit,the speed tracking experiment is carried out,and the average maximum velocity deviation is 0.5m/s,which can effectively track the preset speed and verify the feasibility of the control algorithm. |
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