Patent ID: 9136695
Filing Date: 2015-09-15
Classification: H02H,H02M

Abstract:
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.