Patent ID: 8866422

Claim:
An aircraft motor drive control apparatus for driving a motor mounted in an aircraft to drive a device installed in the aircraft, and controlling an operational status of the motor, comprising: an inverter that has a switching element and drives the motor; and a control unit that performs pulse width modulation control of the inverter, the control unit including: a command signal processing unit that outputs a PWM frequency control signal for controlling a PWM frequency, which is a switching frequency in the switching element, based on a signal from a controller that generates a PWM frequency command signal for specifying the PWM frequency; and a PWM frequency control unit that controls the PWM frequency based on the PWM frequency control signal, wherein the command signal processing unit receives, as the PWM frequency command signal, one of a first PWM frequency command signal and a second PWM frequency command signal, if the command signal processing unit has received the first PWM frequency command signal, the command signal processing unit outputs, as the PWM frequency control signal, a low PWM frequency command signal for causing the PWM frequency control unit to control the PWM frequency so that synchronous PWM control or asynchronous PWM control is performed at the PWM frequency in a predetermined frequency range, if the command signal processing unit has received the second PWM frequency command signal, and until a time period that has passed after the receipt of the second PWM frequency command signal reaches a predetermined time period without receipt of the first PWM frequency command signal, the command signal processing unit outputs, as the PWM frequency control signal, a high PWM frequency command signal for causing the PWM frequency control unit to control the PWM frequency so that synchronous PWM control or asynchronous PWM control is performed at the PWM frequency in a higher frequency range than the predetermined frequency range, and if the command signal processing unit has received the second PWM frequency command signal and the time period that has passed without receipt of the first PWM frequency command signal after the receipt of the second PWM frequency command signal has reached the predetermined time, the command signal processing unit outputs, as the PWM frequency control signal, the low PWM frequency command signal.