FIELD: automatic protection of power lines against substation circuit breaker operation in response to shorted buses. SUBSTANCE: proposed method used for inhibiting closure of automatic load transfer center in response to steady double- or three-phase short circuit at substation buses in absence or presence of automatic reclosing device for lead-in circuit breaker includes recording of short-circuit current through power transformer bushing at the same time checking operating current through power transformer bushing between lead-in circuit breaker and automatic load transfer circuit breaker; recording of short-circuit current between lead-in circuit breaker and automatic load transfer circuit breaker upon its opening due to operation of protective gear; measurement of working current between lead-in circuit breaker and automatic load transfer breaker; if it equals zero, conclusion is made that steady short circuit has occurred at substation buses between lead-in circuit breaker and automatic load transfer circuit breaker in which case automatic load transfer inhibit signal is sent. EFFECT: enlarged functional capabilities and fields of application. 1 cl, 2 dwg
Authors
Dates
2003-12-10—Published
2002-02-13—Filed