【文章內(nèi)容簡介】
ng + Ferroresonance Loss of Coordination +Choice of Grounded Interconnection Transformer Primary Winding. CLEMSON UNIVERSITY DG CONFERENCE Typical 4Wire Distribution Feeder Circuit Poletop transformer rated for linetoneutral voltages example: KV ?3 ? KV DG CLEMSON UNIVERSITY DG CONFERENCE Ungrounded Interconnection Transformers Problems Advantages Can supply the feeder circuit from an underground source after substation breaker A trips causing overvoltage Provide no ground fault backfeed for fault at F1 amp。 F2. No ground current from breaker A for a fault at F3. Low Voltage (SEC.) High Voltage (PRI.) DG CLEMSON UNIVERSITY DG CONFERENCE Grounded Primary Interconnection Transformers Problems Advantages No ground current from breaker A for faults at F3( ). No overvoltage for ground fault at F1. No overvoltage for ground fault at F1. Low Voltage (SEC.) High Voltage (PRI.) Provides an unwanted ground current for supply circuit faults at F1 and F2. Allows source feeder relaying at A to respond to a secondary ground fault at F3( ). DG 2 3 CLEMSON UNIVERSITY DG CONFERENCE FERRORESONANCE NEW YORK FIELD TESTS –1989 FIELD TEST CIRCUIT CLEMSON UNIVERSITY DG CONFERENCE FERRORE