| 摘要 |
A power conversion system includes a capacitor 30 which stores direct current power; an inverter 40, a pair of direct current terminals of which are connected to two ends of the capacitor 30 and to the alternating current terminals of which an alternating current motor 50 acting as a load is connected; an upper and lower arm portion 90 of which the connection point of semiconductor switches 91 and 92 connected in series is connected to the neutral point of the motor 50; a direct current power source 10 connected in parallel to the upper and lower arm portion 90; and a switch 100 connected between one of the direct current terminals of the inverter 40 and one end of the upper and lower arm portion 90, wherein the other direct current terminal of the inverter 40 is connected to the other end of the upper and lower arm portion 90. In a condition in which the switch 100 is turned off, the inverter 40 is caused to operate as a zero-phase converter, and the upper and lower arm portion 90 is switched, thus carrying out a buck-boost of the voltage of the direct current power source 10 and a drive of the motor 50 by the inverter 40 at the same time. By so doing, the need for a boost reactor is eliminated to achieve a reduction in the size of the whole system and a loss reduction, thus enhancing the degree of freedom of the direct current voltage of the inverter 40. |
