SYNTHETIC SHORT-CIRCUIT TESTING METHOD OF BREAKER

PURPOSE:To lengthen an arc without using an arc extension circuit in a synthetic short-circuit test of a breaker. CONSTITUTION:Current is allowed to flow in a sample breaker SP through an auxiliary breaker Sh from a current source circuit 1 and voltage is applied to the sample breaker SP from a voltage source circuit 2. The voltage source circuit 2 and a protective capacitor are separated from a circuit of the current source circuit 1 to the sample breaker S. with switches SW1--SW3 till just after firstly received passage of a current-shorted zero point from just after the contact parting of the sample breaker SP very high transient recovery voltage wherein a short-circuit generator generates natural frequency of 30-50kHz and a bus-line has 500-1000kHz at a short-circuit current zero point is generated for the purpose of extension of an arc. After arc extension, the auxiliary breaker Sh is contact-parted, the switches SW1-SW3 are turned on and regular recovery voltage is generated at a second-time current zero point.