직류 피뢰기용 ZnO 소자의 전기적 특성

The Electrical Characteristics of ZnO varistor for d.c. Arrester

The electrical characteristics of $A{\sim}C's$ ZnO varistors fabricated according to variable sintering condition, which sintering temperature is $l130^{\circ}C$ and speeds of pusher are A: 2mm/min, B: 4mm/min, C: 6 mm/min, respectively, were investigated. The varistor voltage of $A{\sim}C's$ ZnO varistors sintered at $1130^{\circ}C$ increased in order A < B $A{\sim}C's$ ZnO varistors exhibited below 2mA at rated voltage. Lightning impulse residual voltage of A's ZnO varistor suited standard characteristics, which is 3.85kV at 2.5kA, 4.4kV at 5kA and 5.16kV at 10kA. After multi lightning impulse residual voltage test of A's ZnO varistor exhibited good discharge characteristics which ZnO varistor reveals no evidence of puncture, flashover, cracking in visual examination. After high current impulse test of A's ZnO varistor exhibited good discharge characteristics, which variation rate of residual voltage is 0.4% before and after test, and revealed no evidence.