| 摘要 |
PROBLEM TO BE SOLVED: To provide a control method for a direct power converter, capable of preventing commutation failures, without having to adopt a method of increasing the current rating of a semiconductor switch. SOLUTION: This control method of a direct power converter determines the magnitude relation of a three-phase AC voltage in the inside of the control device. When switching on/off a bidirectional switch S<SB>1</SB>is on/off switched, between the maximum voltage phase and one output phase and a bidirectional switch S<SB>2</SB>between the middle voltage phase and the output phase for commutation, a unidirectional switch S<SB>12</SB>for flowing a current from the output phase to the maximum voltage phase inside the bidirectional switch S<SB>1</SB>; and a unidirectional switch S<SB>22</SB>for making a current flow from the output phase to the intermediate voltage phase inside the bidirectional switch S<SB>2</SB>, are turned on, as well as, via a unidirectional switch S<SB>32</SB>, that makes a current flow from the minimum voltage phase to the output phase in the inside of the bidirectional switch S<SB>3</SB>between the minimum voltage phase and the output phase is turned on, and the bidirectional switches S<SB>1</SB>, S<SB>2</SB>are switched on/off. COPYRIGHT: (C)2008,JPO&INPIT
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