Protection control system for a multilevel power conversion circuit

摘要

Aspects of the invention are directed to a protection control system of the invention is a protection control system for a multilevel power conversion circuit of a flying capacitor type, the power conversion circuit including six semiconductor switches of first through sixth semiconductor switches sequentially connected in series from a positive terminal to a negative terminal of a DC power supply, a first capacitor connected between the connection point of the second and third semiconductor switches and the connection point of the fourth and fifth semiconductor switches and a second capacitor connected between the connection point of the first and second semiconductor switches and the connection point of the fifth and sixth semiconductor switches, wherein the protection control system of the invention turns ON the second semiconductor switch or maintains the second semiconductor switch in an ON state, in the case of short-circuit fault of the third semiconductor switch.

主权项

1. A protection control system for a multilevel power conversion circuit of a flying capacitor type for converting a DC power into an AC power or converting an AC power into a DC power, one phase portion of the power conversion circuit comprising:
six semiconductor switches of first through sixth semiconductor switches sequentially connected in series from a positive terminal to a negative terminal of a DC power supply circuit, each semiconductor switch having an antiparallel-connected diode; a gate driving circuit with an arm short-circuit protection circuit connected to a gate terminal of each semiconductor switch; a first capacitor connected between a connection point of the second and third semiconductor switches and a connection point of the fourth and fifth semiconductor switch; a second capacitor connected between a connection point of the first and second semiconductor switches and a connection point of the fifth and sixth semiconductor switches; and an AC terminal at a connection point of the third and fourth semiconductor switches; wherein the protection control system turns ON the second semiconductor switch or maintains the second semiconductor switch in an ON state, in a case of short-circuit fault of the third semiconductor switch.