Interface arrangement between AC and DC systems using grounding switch

摘要

An interface arrangement for connection between an AC system and a DC system and to a method of disconnecting a DC system from an AC system are disclosed. The arrangement includes a converter for conversion between AC and DC having a DC side for connection to the DC system and an AC side for being coupled to the AC system, a set of circuit breakers coupled between the AC side of the converter and the AC system and a breaker assisting unit including a set of branches connected between the AC side of the converter and ground, where each branch includes a switch in series with an impedance element.

主权项

1. An interface arrangement for connection between an AC system and a DC system and comprising:
a voltage source converter for conversion between AC and DC, said converter having a DC side for connection to said DC system and an AC side for being coupled to said AC system; a set of circuit breakers coupled between the AC side of the converter and the AC system; and a breaker assisting unit comprising a set of branches connected between the AC side of the converter and ground, where each branch includes a switch in series with an impedance element, wherein the circuit breakers are closed and the switches are open in normal operation, and the interface arrangement further comprises a control unit configured to close the switches of the branches upon the occurrence of a fault for ensuring zero-crossings in currents flowing through the circuit breakers and to open the circuit breakers at such zero-crossings.