Research On Dynamic Characteristic Of Vacuum Circuit Breaker Influenced By Temperature

In power gird,accuracy and stability of circuit breaker operation is the premise to realize intelligent switching control.Ambient temperature is one of the factors that affect the accuracy of switch operation.The influence of ambient temperature on the operation characteristic of circuit breaker is obvious and difficult to control,in the case of higher requirement of time and accuracy of breaker operation,such as synchronous closing technique,the error due to temperature influence should be compensated.When the temperature changes,the parameters of the whole control operation system of the permanent magnetic actuator circuit breaker will be changed,respectively: internal capacitance,capacitance equivalent series resistance,coil resistance,permanent magnet parameters and motion damping.In this paper,a series of temperature tests were carried out to obtain the law of each parameter and the operation characteristic with temperature;it is found that,the law of these parameters except for motion damping are consistent with the theory;the closing time of the prototype decreases first and then increases with the increase of temperature,and the time is shorter at 20?;for the problem that the motion damping cannot be quantified,this paper propose a method of combining the prototype experiment and ANSYS simulation to analyze the motion damping;then,based on MATLAB fitting tool,get the formula of damping and movement,the relationship between temperature and formula ratio of motion damping and stroke conforms to the Gauss distribution.In order to represent the error between simulation and experiment caused by uncontrollable variables such as motion damping,the ratio of simulation closing time to prototype closing time is defined as the simulation integrated work efficiency,under the experimental conditions,the simulation integrated work efficiency is between 70%-90%,which increases first and then decreases with the increase of temperature,and it is the highest at 40?.To avoid the uniqueness of the experimental results of the single circuit breaker,a series of temperature experiments were carried out on three circuit breakers with same stroke,including the prototype temperature test and the simulation temperature test,compare and analysis the operating characteristics and simulation integrated work efficiency variation with temperature.Three circuit breakers are classified into two categories: same stroke same size,same stroke different size.The results show that the operating characteristics with the influence of temperature are consistent,the closing time decreases first and then increases with the increase of temperature,and the closing time of low temperature is slightly higher than that on high temperature.Based on MATLAB fitting tool,the relationship between the efficiency and the temperature of the simulation work of three circuit breakers are fitted,and the fitted formulas are basically consistent with the polynomial distribution.This paper puts forward a method of calculating the motion damping,and analysis of simulation integrated work efficiency changes with temperature,which can provide theoretical guidance for the simulation research and synchronous closing technology of the permanent magnet actuator considering the temperature,improve efficiency and reduce the manpower.