Patent ID: 7791911

Claim:
An inverter device comprising: a converter circuit that rectifies a first alternating current output from a power supply to generate a rectified current; a capacitor that stores therein the rectified current and outputs a direct current based on the rectified current; an inverter circuit that converts the direct current into a second alternating current for driving a load; a voltage control unit that, during a period when any one of an instantaneous power cut and an instantaneous voltage drop occurs in the power supply, generates and outputs a first current command based on a voltage of the capacitor and a q-axis voltage command; and a current control unit that generates and outputs, based on the first current command, the q-axis voltage command for controlling the inverter circuit to output the second alternating current, wherein the voltage control unit generates the first current command i q *: i q *=i dc *×V dc /V q * where V dc is the voltage of the capacitor, V q * is the q-axis voltage command, and i dc * is a current that should flow in the capacitor.