Study On The Interruption Capacity Of LTVS With Different Magnetic Fields

Nowadays,the pulsed power technology puts forward higher requirements for the trigger and interruption performance of switch facility,so it is imperative to develop a pulse power switch with better comprehensive performance.As a novel switch in pulsed power facilities,Laser triggered vacuum switch(LTVS)combines the features of TVS and LTGS,and generates the initial plasma to trigger the vacuum gap by the thermal interactions of the laser beam with target materials.With its superior performance such as shorter delay time,higher trigger reliability and longer lifetime,LTVS has been applied in electromagnetic launch,power system protection and other fields,and has shown great prospects.Since previous studies on LTVS mainly concern about the trigger characteristics and the improvement of trigger performance,there are few researches on its interruption performance.The paper firstly discusses the interruption mechanism of LTVS based on the interruption process of TVS,and respectively explains the mechanism of the electrode's self-generated magnetic field and external magnetic field on vacuum arc.The 3-D simulation models of AMF electrode and TMF electrode are built up through SolidWorks software,and the electromagnetic field simulation analysis is performed by Ansoft Maxwell software.Combined with the simulation results,the influence of the magnetic field on the LTVS interruption capacity is discussed and analyzed.Secondly,the interruption test platform of LTVS is established based on detachable vacuum chamber.The cup-shaped AMF electrode and the spiral-shaped TMF electrode are selected to investigate the effect of electrode spacing,current frequency and polarity configuration,and the triggering material on the interruption capacity of LTVS under different electrode self-generated magnetic fields.The test results prove that,the interruption capacity of LTVS from TMF electrodes is obviously better than that from AMF electrodes,and gradually decreases with the rise of electrode spacing,especially the TMF electrodes.Affected by the trigger material,when the LTVS with KCl+Ti is of positive polarity,the increase of current frequency seriously reduces the interruption capacity of LTVS,while the change of frequency has no significant influence on it under the negative polarity.Influence of polarity configuration on the interruption capacity of LTVS depends on the characteristics of target material.Under different polarity configurations,the charged particles released bythe active trigger materials at current-zero will affect the high-frequency interruption capacity of LTVS to varying degrees.Finally,a pulse magnetic field generator is developed to apply a pulsed magnetic field with adjustable strength,direction,and application time to LTVS under the AMF electrode.The interruption capacity of LTVS under different external magnetic fields is carried out,and a reasonable magnetic field control strategy is proposed to further improve its interruption capacity.The results show that a pulsed TMF with a certain magnetic field strength near the current-zero can improve the interruption capacity.