Verbesserungen an oder im zusammenhang mit ketten-link-modulen für spannungszwischenkreisumrichter

Abstract

In the field of chain-link modules for voltage source converters, there is a need for an improved chain-link module. A chain-link module (10), for connection in series with other chain-link modules to form a chain-link converter selectively operable to provide a stepped variable voltage source within a voltage source converter, comprises at least one pair (12) of series-connected switching elements (14) that are connected in parallel with a plurality of series-connected energy storage devices (18, 20). Each energy storage device (18, 20) has an auxiliary power supply unit (30, 32) connected in parallel therewith to source energy therefrom for supply to an auxiliary chain-link module control circuit (34). The chain-link module (10) also includes a modulation controller (36) which is interconnected between each auxiliary power supply unit (30, 32) and the auxiliary chain-link module control circuit (34). The modulation controller (36) is configured to modulate the proportion of energy supplied to the auxiliary chain-link module control circuit (34) by each auxiliary power supply unit (30, 32).