Synthetic making/breaking-capacity test circuit for high-voltage alternating-current circuit-breakers

摘要

A high-voltage oscillating circuit (I) is connected in parallel with an auxiliary circuit-breaker (B_a) by firing a switching spark gap (SG_hv) and the oscillating current (i_hv) is superimposed on the high-current (i_hc) with opposite polarity just before the high-current zero crossing. The spark gap (SG_hc) is fired at the artificial current zero, causing: short-circuiting of the high-current source (a), series connection of the high-voltage oscillating circuit with the test circuit-breaker (B_t), oscillating current from the auxiliary circuit-breaker is transferred with constant parameters to the test circuit-breaker there—in following the eliminated high current. Transient high voltage follows the zero crossing of the synthetic current continuously.