Methods for de-energizing a chain-link converter, controller, computer programs and computer program products

摘要

A method for de-energizing a chain-link converter including one or more phase legs each phase leg having a number of series-connected converter cells. The phase legs are connected to a respective charging resistor. The method includes the steps of: opening AC circuit breakers arranged between a power grid and the chain-link converter, opening charging resistors switches arranged in parallel with a respective one of charging resistors, and circulating a current within the chain-link converter through the charging resistors and each phase leg, whereby the DC capacitor are discharged. The invention also relates to a controller, computer program and computer program products.

主权项

1. A method for de-energizing a chain-link converter comprising one or more phase legs, each phase leg comprising a number of series-connected converter cells, each converter cell comprising four valves arranged in an H-bridge connection with a DC capacitor, and each valve in turn comprising a semiconductor switch in parallel with a diode, the phase legs being connected to a respective charging resistor, the method comprising the steps of:
opening AC circuit breakers arranged between a power grid and the chain-link converter, opening charging resistors switches arranged in parallel with a respective one of charging resistors, and circulating a current within the chain-link converter through the charging resistors and each phase leg, whereby the DC capacitor are discharged.