| 摘要 |
PROBLEM TO BE SOLVED: To provide a power converter capable of conducting reduction in the generating loss of a switching element, proper measures against rapid decrease in system voltage, and prevention of effects on an AC power system caused by switching the pulse number of PWM. SOLUTION: If alternating current increases and an alternating current peak- to-peak from an alternating current peak-to-peak calculating unit 109 exceeds a prescribed value designated by a carrier wave switching commander 110, the carrier wave switching commander 110 issues a command to switch to the carrier waves of carrier generators 101-104 on a low pulse number side to carrier wave switches 115-118. As a result, self-excited power conversion units 1-4 to a single-pulse operation respectively. |
