| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the following problem: in multilevel conversion equipment, a capacitor series circuit is used in a direct current portion and parts such as semiconductor switches and a reactor are added to the exterior so as to balance the voltages, but this leads to an increase in the size and cost of the equipment. <P>SOLUTION: Power conversion equipment is configured by connecting a capacitor series circuit in parallel with a direct-current power supply. The capacitor series circuit is used as direct-current input and the power conversion equipment outputs alternating-current voltage having three or more potentials in a half-cycle period. A neutral point of an alternating-current load and an intermediate connection point of the capacitor series circuit are directly connected. The voltage of each of the capacitors is detected, and a zero voltage vector obtained by setting each alternating-current output at the same potential is adjusted in accordance with a difference between the voltages. <P>COPYRIGHT: (C)2011,JPO&INPIT |
