Electric motor drive device

Abstract

An electric motor drive device that includes an electric motor, a main circuit, a current sensor, and a control unit. The electric motor has a plurality of windings. The main circuit transforms power into AC power and supplies the AC power to each of the plurality of windings. The current sensor detects a load current flowing through each of the windings. The control unit controls the main circuit on the basis of a current value detected by the current sensor and controls an amount of power to be supplied from the main circuit to the electric motor on the basis of an amplitude of the load current associated with detection of an undervoltage state of the AC power supply in a state in which the main circuit uses conversion rule in which an index value for the amplitude of the load current flowing through the plurality of windings is defined.

Dependencies are inferred from the claim text.