Experimental research on dynamic dielectric recovery characteristics for vacuum switch with double-break

Based on the equivalent model of vacuum switch with double-break, the dynamic dielectric recovery characteristics of the vacuum switch with double-break were analyzed; the experimental model of vacuum switch with double-break in series was set up, and the transient recovery voltage distribution property of experimental model was studied. The fault current was interrupted under the following cases: two breaks with or without parallel grading capacitors interrupt synchronously or asynchronously. The experimental results showed that the successful interruption of vacuum switch with double-break mostly due to the voltage sharing distribution of the two breaks in the dielectric recovery process. The voltage distribution of the two breaks is mainly decided by their arc resistances in the dynamic dielectric recovery process, whereas it is decided by their parallel capacitors after the dynamic dielectric recovery process. Therefore, applying a low dispersion actuator and selecting proper interrupter grading capacitors become key factors for double and multi-break vacuum switch to interrupt successfully.