耦合电容法真空度检测中测量距离对场强影响的研究

摘要

真空断路器是电器设备的保护和控制的重要开关设备.灭弧室真空度会随着真空断路器运行时间而逐渐降低,影响断路器正常工作,所以需要精确观测其变化情况.耦合电容式作为主要的真空度在线监测方法之一,可以有效地测得灭弧室真空度变化.然而电场传感器的插入不可避免的会影响到灭弧室周边电场分布,加大真空度检测误差,从而对电力系统运行造成安全隐患.通过有限元分析软件ANSYS,对加入传感器后不同测量距离下的灭弧室周边电场进行仿真计算.仿真结果表明灭弧室与传感器安全距离范围为50-70mm之间时,对周边电场影响最小.并根据模拟数据分析结果,为消除耦合式电容电场传感器对真空度检测安全隐患,提供了理论依据.%The vacuum circuit breaker is the important switchgear for the protection and control of electrical equipment.The vacuum degree of arc chamber will gradually decrease with the service time of vacuum breaker,while affecting the normal working of the circuit breaker,so it is necessary to accurately observe the changes.Coupling capacitance as the primary one of the methods for the online monitoring of the vacuum degree,can effectively measure the changes in the vacuum degree of the interrupter.However,the insertion of electric field sensor will inevitably affect the surrounding electric field distribution of arc chamber,detection errors of the vacuum degree will increase,thus a safety hazard may be caused on power system operation.In this paper,the finite element analysis software ANSYS was applied on the simulation of surrounding electric field of the arc chamber under different measurement distances after adding the sensor.The simulation results showed that when the safe distance range of arc chamber and sensor is between 50mm-70mm,the impact on the surrounding electric field is the minimum.Based on the statistical analysis of the results,it provides a theoretical basis for the elimination of security risks when applying the coupling capacitor electric field sensor to detect the vacuum degree.