Patent attributes
An inverter device includes a three-phase inverter, which has switching elements, and a controller, which is programmed to perform two-phase modulation control on switching of the switching elements between an ON state and an OFF state. The controller computes the power factor of a load. The controller determines whether or not the computed power factor is less than a preset threshold value. If the computed power factor is greater than or equal to the threshold value, the controller performs a phase shift to shift the central time point of an ON period or an OFF period for two phases other than a stop phase in the two-phase modulation control by 180 degrees, and if the computed power factor is less than the threshold value, the controller supplies the switching elements with ON and OFF control commands to perform the two-phase modulation control without performing the phase shift.