Research On The Detection Of Vacuum Pressure In Vacuum Circuit Breaker

In recent years, the vacuum switches are applied more increasingly in the field ofmedium voltage distribution due to its unique superiority. Vacuum arc extinguish chamberis the core component of the vacuum switch, vacuum pressure is one of the importantparameters of the vacuum arc extinguish chambers. The insulating ability of the vacuumarc extinguish chamber is related to its vacuum pressure, the performance of vacuumswitch can be guaranteed only when its vacuum pressure is in a certain range. Thedetection of the vacuum pressure of the vacuum arc extinguish chambers is generallydivided into offline detection and online detection, to carry out the vacuum pressure ofdetecting methods and online detection technology has important theoretical and practicalsignificance.This paper describes the current domestic and international vacuum degree of vacuuminterrupter test method.Firstly, in this paper the current domestic and international detecting methods aboutvacuum pressure of vacuum arc extinguish chambers are described.On this basis, this paper focuses on the principle of magnetron discharge method, andaccording to the principle the experimental hardware block diagram is designed, maincircuit is made up by high frequency high voltage module, the excitation coil rectifiermodule, data measurement acquisition module. High-frequency high-voltage modulethrough labor frequency signal by rectifying oscillation and resulted in high-voltagehigh-frequency signal is applied between the two contacts at both ends of the vacuum arcextinguish chambers, a strong electric field is formed between the contacts and the shield,axial magnetic field is applied by excitation coil in the arc chamber to make two contactsforming a discharge, discharge current is collected by signal acquisition module, multiple sets of data are compared and then comes to the relationship between the vacuum pressureof vacuum arc extinguish chambers and the discharge current.In order to solve the problem about the online monitoring of vacuum pressure ofvacuum circuit breaker in10kV ring network switch cabinet, a novel method based on thephased magnetic field is discussed. If the vacuum pressure of certain phase of VCBs incertain groups is increased, the flux density of adjacent center points change, and the fluxdensity difference between the other two center points also changes from a constant valueto the variation based on the function. By means of the difference, the vacuum circuitbreaker group that the vacuum pressure of certain phase of vacuum circuit breaker isincreased can be confirmed. Though simulating by ANSOFT MAXWELL the feasibility ofthe method is verified.