Abstract: A motor controller includes an AC-to-DC converter that converts AC power from an AC power source into DC power and supplies the DC power to a DC bus line, an auxiliary power source that charges the DC bus line with the DC power and discharges the DC power from the DC bus line, and a first inverter that controls power supply to a motor using the DC power from the DC bus line. The auxiliary power source includes a rotating electrical machine, a flywheel connected to the machine, a second inverter that supplies power to the machine using the DC power on the DC bus line and regenerates the power from the machine into the DC power on the DC bus line, and control circuitry that controls the second inverter to cause rotational angle velocity of the flywheel to keep positive correlation with bus-to-bus voltage of the DC bus line.

Abstract: A motor control system includes a DC-to-DC converter including a semiconductor switch and a reactor that cooperates with the switch to convert input-side DC bus voltage across first and second input-side DC buses into predetermined output-side DC bus voltage across first and second output-side DC buses and to output the output-side voltage, control circuitry that controls duty factor of the switch and determine, based on input-side detection value of the input-side voltage and output-side detection value of the output-side voltage, whether there is failure in the system when the factor is 100 percent and reactor-current detection value of reactor current through the reactor is approximately zero, a smoothing capacitor connected to the output-side buses and disposed between the output-side buses, and an inverter that is connected to the capacitor through the output-side buses, converts DC power from the output-side buses into AC power and supplies the power to a motor.

Abstract: A motor control system includes a DC-to-DC converter including a semiconductor switch and a reactor that cooperates with the switch to convert input-side DC bus voltage across first and second input-side DC buses into predetermined output-side DC bus voltage across first and second output-side DC buses and to output the output-side voltage, control circuitry that controls duty factor of the switch and determine, based on input-side detection value of the input-side voltage and output-side detection value of the output-side voltage, whether there is failure in the system when the factor is 100 percent and reactor-current detection value of reactor current through the reactor is approximately zero, a smoothing capacitor connected to the output-side buses and disposed between the output-side buses, and an inverter that is connected to the capacitor through the output-side buses, converts DC power from the output-side buses into AC power and supplies the power to a motor.