| 摘要 |
PURPOSE:To reduce the ratio of harmonic wave content of the 3-phase AC voltage waveform of an inverter device by always comparing the 3-phase AC voltage of the respective output terminals between the phases with a copy reference signal and feeding back the compared result to the switching control terminal of a main inverter circuit. CONSTITUTION:3-Phase AC voltages (the output waveforms of filters 7-9) between the output terminals U and V, V and W, W and U of the three phases are always compared with a copy reference signal, and the compared signal is fed back to a main circuit (such as BU2). Since the variation in the counterelectromotive force generated from a motor corresponds to the operation of a control circuit in this manner, the 3-phase AC voltage waveforms applied to the motor are stabilized to eliminate the occurrence of deformation in the waveform of the conventional device. Accordingly, the ratio of harmonic wave content of the 3-phase AC voltage waveforms can be reduced at the time of varying the counterelectromotive force generated from the motor. |
