Method and Apparatus for Transferring Power Between AC and DC Power Systems

摘要

In one aspect of the teachings herein, a self-commutated current source converter is operated in a manner that compensates for the reactive power consumption and/or harmonics generation of a line-commutated current source converter used in the transfer of electrical power between an AC power system and a DC power system. In this regard, the line-commutated current source converter is operated as a first converter in a hybrid converter apparatus and the self-commutated current source converter is operated as a second converter in the hybrid arrangement. According to one example, the first and second converters are stacked, such that each shares a portion of the DC voltage on the DC side of the hybrid converter apparatus, while in another example, the second converter is not used for power conversion and instead is used solely for compensation with respect to the first converter.

主权项

1. A hybrid converter apparatus configured for coupling to an AC power system on an AC side and to a DC power system on a DC side, said hybrid converter apparatus comprising:
a line-commutating current source converter referred to as a first converter and comprising a plurality of line-commutated bidirectional voltage-blocking switches coupled between first AC-side and DC-side connections and configured for transferring electrical power between the AC and DC power systems, based on converting AC voltage to DC voltage or vice versa; a self-commutating current source converter, referred to as a second converter and comprising a plurality of self-commutated bidirectional voltage-blocking switches coupled at least to the AC power system through second AC-side connections; and a control circuit configured to control commutation of the second converter to compensate for at least one of reactive power consumption and harmonics generation by the first converter on the AC side.