HV switch for large transformers - has series switch paths bridged by parallel resistor and by resistor and series secondary switch path

摘要

The HV switch has at least two series switch paths (6,7) one of which is bridged by a resistor (8) and the other being bridged by a resistor (10) in series with a secondary switch path (9). Pref. the secondary switch path is closed first, followed by closure of the first switch path (6) bridged only by the resistor (8) and finally closure of the second switch path (7).S The first switch path is pref. used for switching transformers, while the second switch path is used for switching short-circuit currents. The resistor (8) across the first switch path may comprise a voltage-dependant resistance. The switch is used for large transformers with the switch paths operated one after the other with intermediate delays of 10 ms.