SEMICONDUCTOR SWITCHING STRING

摘要

A semiconductor switching string includes a plurality of series-connected semiconductor switching assemblies, each having a main semiconductor switching element that includes first and second connection terminals. The main semiconductor switching element also has an auxiliary semiconductor switching element electrically connected between the first and second connection terminals. Each semiconductor switching assembly also includes a control unit configured to switch on a respective auxiliary semiconductor switching element to selectively create an alternative current path between the first and second connection terminals whereby current is diverted to flow through the alternative current path to reduce the voltage across the corresponding main semiconductor switching element. The or each control unit is further configured to switch on the auxiliary semiconductor switching element when the voltage across the corresponding main semiconductor switching element differs from a voltage reference derived from the voltage across all of the main semiconductor switching elements.

主权项

1. A semiconductor switching string, for use in a HVDC power converter, comprising:
a plurality of series-connected semiconductor switching assemblies, each semiconductor switching assembly having a main semiconductor switching element including first and second connection terminals between which current flows from the first terminal to the second terminal when the main semiconductor switching element is switched on, the main semiconductor switching element having an auxiliary semiconductor switching element electrically connected between the first and second connection terminals thereof; and a control unit operatively connected with each auxiliary semiconductor switching element, the or each control unit being configured to switch on a respective auxiliary semiconductor switching element to selectively create an alternative current path between the first and second connection terminals associated therewith whereby current is diverted to flow through the alternative current path to reduce the voltage across the corresponding main semiconductor switching element, and the or each control unit being further configured to switch on the said respective auxiliary semiconductor switching element when the voltage across the corresponding main semiconductor switching element differs from a voltage reference derived from the voltage across all of the main semiconductor switching elements in the semiconductor switching string.