Patent ID: 9670917
Date: 2017-06-06
CPC Classifications: F04B,H02P

Claim:
1. An aircraft motor drive control apparatus for driving a three-phase motor mounted in an aircraft to drive a device installed in the aircraft, and controlling an operational status of the three-phase motor, comprising: a three-phase inverter circuit that has switching elements and drives the three-phase motor; and a controller that performs pulse width modulation control of the three-phase inverter circuit, the controller comprising: a three-phase modulation voltage command value generation unit that generates a three-phase modulation voltage command value as a voltage command value for specifying a voltage to be applied to the three-phase motor; a two-phase modulation voltage command value generation unit that generates, as the voltage command value, a two-phase modulation voltage command value for alternately fixing an on/off state of a switching element of one phase in the three-phase inverter circuit, and modulating on/off states of switching elements of the other two phases; a voltage command switching unit for configuring a setting so as to switch the voltage command value from one of the three-phase modulation voltage command value and the two-phase modulation voltage command value to the other, based on a determination value that is used in determination, which is one of a value of a rotational speed of the three-phase motor and a value of a torque current component of the three-phase motor; and a PWM signal output unit that generates a PWM signal for performing pulse width modulation control of the three-phase inverter circuit based on the voltage command value generated as the three-phase modulation voltage command value or the two-phase modulation voltage command value, and outputs the PWM signal to the three-phase inverter circuit, wherein the voltage command switching unit sets the voltage command value to the three-phase modulation voltage command value until the determination value first reaches a predetermined first threshold value after the three-phase motor starts to rotate, switches the voltage command value to the two-phase modulation voltage command value when the determination value becomes larger than or equal to the first threshold value, and switches the voltage command value to the three-phase modulation voltage command value when the determination value becomes smaller than a predetermined second threshold value, which is smaller than the first threshold value, and the voltage command switching unit switches the voltage command value from the three-phase modulation voltage command value to the two-phase modulation voltage command value at the time when a voltage difference between voltage command values for two of three phases in the three-phase modulation voltage command value becomes zero and when it is determined that a failure does not occur in the aircraft motor drive control apparatus and the three-phase motor, the failure being at least one of occurrence of overcurrent and an abnormal temperature increase.