| 摘要 |
An inverter apparatus comprises an inverter circuit using pairs of switching elements. The pseudo AC voltage of each phase of this inverter circuit is controlled by pulse modulation using pulses generated by a PWM generator, and the pseudo AC voltages are applied to a power supplied load. The average voltage of respective phases of the output voltages applied to the power supplied load is detected as a virtual neutral voltage corresponding to the neutral voltage of the power supplied load by detecting the voltage at a common node where the phases of a voltage detecting circuit provided between the inverter circuit and the power supplied load are connected. The detected virtual neutral voltage is fed back for controlling the output duty of each phase by the PWM generator. Thus the output voltage of each phase from the inverter circuit is controlled so as to become a target output voltage. The target output voltage can be accurately obtained stably at all times. |
