Three-phase static var compensator arrangement

摘要

PCT No. PCT/GB96/02912 Sec. 371 Date Jul. 28, 1998 Sec. 102(e) Date Jul. 28, 1998 PCT Filed Nov. 27, 1996 PCT Pub. No. WO97/20374 PCT Pub. Date Jun. 5, 1997A polyphase thyristor-switched-capacitor static var compensator (SVC) arrangement employs a transformer circuit connected to the capacitors of the SVC and configured such that when the capacitors are switched out of circuit in sequence, a residual charge on the capacitors is reduced by the transfer of energy between the capacitor and an energy-dissipation circuit by way of the transformer circuit. The primaries of the transformer circuit are connected across respective capacitors, while the secondaries are connected in series in a delta configuration. Damping resistors may be connected in series with the primaries to help dissipate the capacitor energy. The transformer circuit may be saturable and may be constituted by individual transformers or one polyphase transformer. An alternative configuration applicable to a three-phase system employs a single-phase transformer having its primary connected across two series-connected capacitors of two of the phases, while its secondary is connected across the remaining capacitor.