| 摘要 |
PURPOSE: To reduce switching loss and also feed back the regenerated current with one current control by keeping one of the transistor of a phase, where the absolute value becomes maximum out of three-phase AC voltage, on, and PWM-controlling the transistor of the other phase, according to the DC current held as a sample. CONSTITUTION: In the case of converting AC into DC, it is converted into DC by the diodes d1 -d6 of a converter 1. On the other hand, in the case of regenerating the regenerative power from an inverter circuit to the side of AC power source, block data are made from three-phase AC voltage by a comparator 8, and the selection of transistor T21 -T26 corresponding to the block and the setting of switches 9 and 10 are performed, and ON/OFF control is performed by a PWM control circuit 5. Here, one transistor of the phase where the phase voltage becomes maximum out of the transistors T21 -T26 is kept on, and also Tr of the other phase is controlled, according to the DC current value obtained through a sample and hold circuit 2, so as to perform feedback control. |
