A control device includes first and second input terminals to which a DC voltage for driving a motor is input, and a control unit. The control unit sets a rotation direction of the motor based on first input to the first input terminal or the second input terminal. A rotation speed of the motor is changed based on a subsequence input of the DC voltage.

A system includes a starter generator configured to provide power to a first bus and a first inverter, a second inverter coupled to the first inverter, a first switch configured to selectively couple the second inverter to the first bus and to a second bus, a second switch configured to selectively couple a first motor to the first bus and to the second bus, and a controller. The controller sets the first switch to a second position and the second switch to a second position, causes the second inverter to convert the power from the first inverter to a starting power for starting the first motor, causes the second inverter to increase the starting power to match the power provided to the first bus from the starter generator, and switches the second switch to the first position, when the starting power matches the power from the starter generator.

Methods and apparatus for open loop startup of a three-phase motor that reduces acoustic noise. During rotor alignment of the motor, there is a maximum level for a phase current to the motor. After the rotor alignment, open loop motor startup is performed during which the phase current has a first slope. At a selected time, such as when a frequency of the phase current reaches a first threshold, the phase current transitions to a second slope.

A system is for a machine having an alternating current (AC) power source with a first side and a second side, one or more windings, an AC polarity detector, a Hall effect device, two or more pairs of power switches, and a motor controller. The motor controller determines which of the power switches to open or close to obtain a direction of current flow through the one or more windings based on signals from the AC polarity detector and the Hall effect device.

A converter controller configured to control a firing phase of a converter includes an integral element integrating a deviation of DC current from a current command value and generates a voltage command value of output voltage of the converter by performing control calculation of the deviation. In a first mode of performing commutation of an inverter by intermittently setting DC current to zero, the converter controller sets DC current to zero for a predetermined pause time by narrowing a phase control angle simultaneously with a commutation command for the inverter. When the control calculation is resumed immediately after the pause time, the converter controller uses a control amount calculated in control calculation immediately before the pause time as a preset value of the integral element immediately after the pause time.

An input voltage control method includes: a power supply, a first rectifier circuit and a second rectifier circuit connected between the positive terminal and the negative terminal of the power supply. The first rectifier circuit and the second rectifier circuit are connected in parallel with each other, an output end of the first rectifier circuit is connected to the motor via a driver circuit. An output end of the second rectifier circuit is connected to a controller through a voltage detection circuit. The controller collects a bus current value and collects a bus voltage value. The controller stores a target duty cycle value and a target voltage value. The controller determines a corresponding target voltage value based on the collected bus current value and obtains an output control duty cycle to drive the motor.

A method is described for controlling an electric motor having a rotor. The method is carried out after a shutdown of the motor has been initiated. The method includes starting a timer in a motor controller, performing regenerative braking to recapture kinetic energy from the rotor as electrical energy, and using the recaptured electrical energy from the regenerative braking to power the motor controller. If the timer in the motor controller exceeds a predetermined timer value, a flag is set in memory in the motor controller to indicate that the motor has stopped.

A method is described for controlling an electric motor having a rotor. The method is carried out after a shutdown of the motor has been initiated. The method includes starting a timer in a motor controller, performing regenerative braking to recapture kinetic energy from the rotor as electrical energy, and using the recaptured electrical energy from the regenerative braking to power the motor controller. If the timer in the motor controller exceeds a predetermined timer value, a flag is set in memory in the motor controller to indicate that the motor has stopped.

A method for determining a stator current vector for starting a synchronous machine of a drive of a passenger transportation apparatus having a rotor and a stator with a stator winding may involve imposing different stator current vectors with different stator current vector directions on the stator winding over the course of a plurality of current application operations, determining from the different stator current vectors a minimum stator current vector with a minimum stator current vector direction at which a minimum driving torque acting on the rotor is generated in the synchronous machine, determining a starting stator current vector with a starting stator current vector direction from the minimum stator current vector, and imposing the starting stator current vector on the stator winding for starting the synchronous machine.

A heat pump device includes an inverter control unit outputting PWM signals to an inverter; a current detection unit detecting a current value flowing in the inverter and outputting the current value after reducing a current value having a first frequency or higher in detected current value; and a drive-signal stop unit that, when the current value output from the current detection unit is equal to or larger than an interruption level, stops output of PWM signals to the inverter. Particularly, the inverter control unit generates a voltage command value such that the voltage command value becomes a value equal to or larger than a lower limit determined according to the first frequency and generates PWM signals based on generated voltage command value and a carrier signal, thereby causing a voltage output time to the motor to be a predetermined time or longer.