AC current detecting device for inverter apparatus and AC current detecting method therefor

摘要

Establishing a current detection system good in accuracy allows implementation of a reduction in the size of an inverter apparatus good in current detection accuracy, even if the number of current sensors is reduced. A current sensor of a DC section and a current sensor corresponding to one phase of an output AC current are used, and means for determining switching patterns of DC main elements and determining a current component of Idc or means for detecting a maximum value of Idc is used, thereby determining an AC current value and a power factor angle.