Comparing direct and synthetic tests for interruption of line-charging capacitive current

Using a validated are model, this paper analyzes current distortion and vol tage waveforms during both direct and synthetic tests for interruption of l ine-charging capacitive current by power circuit breakers. Although the vol tage of the electric are drawn between breaker contacts may produce signifi cant current distortion, it is demonstrated that the most significant param eter affecting the breaking capacity of power circuit breakers in capacitiv e-current switching tests is the voltage Jump appearing across breaker cont acts immediately after current Interruption. It is essential to correctly d efine the supply circuit impedances and the associated voltage jump so as n ot to reduce or increase this test severity unduly.