A compressor driving apparatus and an air conditioner including the same, whereby the compressor driving apparatus includes a capacitor connected to a DC terminal, an inverter, including a plurality of three-phase switching devices, to convert DC power from the capacitor into AC power to drive a compressor motor, an output current detector to detect output current flowing in the motor, and a controller to output a switching control signal for controlling the inverter based on the output current, wherein the controller performs control such that some of the three-phase switching devices in the inverter are turned on or off in a compressor preheating mode.

A motor starting state recognition method and device, and a motor. The method includes sampling the counter electromotive forces of any two phases of a motor, and calculating a linear counter electromotive force of the motor according to the counter electromotive forces of the two phases, acquiring a polarity flag bit of the motor, and determining the starting state of the motor according to the polarity flag bit and the linear counter electromotive force. The state of a motor before starting can be recognized effectively using the method, so that the problem where a motor may not be started normally or the success rate of starting is low under the condition of a favorable/dead wind is effectively solved, and the problem where a motor becomes severely worn out and has a shorter service life after frequent starting due to starting failure is avoided. Moreover, the method is simple and highly accurate, and the success rate and reliability of system starting are effectively improved.

A device and method for detecting the number of revolutions of a sensorless electric park brake (EPB) motor. The device for detecting the number of revolutions of a sensorless motor includes: an actuator driving motor used to set and release a parking brake of an EPB system; an electronic control module for controlling the motor, a vehicle battery for supplying power to the motor and the electronic control module; and a main processing unit for receiving an output signal of the electronic control module and estimating the number of revolutions of the motor, wherein the electronic control module further includes a ripple measuring unit for receiving an output signal of the motor and measuring a ripple of the motor.

A method for determining a speed (nG) of a generator unit which has an electric machine (100) with a rotor winding (110) and a stator winding (120) and a rectifier (130) connected thereto, via which rectifier the electric machine (100) is connected to an electrical system (150) of a motor vehicle, the speed (nG) being determined depending on the plot of an excitation current (IE) flowing through the rotor winding (110) of the electric machine (100). In particular, the speed is determined from a known relationship between the speed, the frequency of the excitation current, the number of pole pairs and optionally the number of phases when there is an error that leads to a constant phase voltage being output.

A control device comprises a driving unit configured to drive a plurality of coils of a multiple-phase motor by pulse width modulation; a detection unit configured to detect currents flowing through the plurality of coils in a time-division manner; and a change unit configured to change, in accordance with a duty in the pulse width modulation, a sequence of detecting the currents flowing through the plurality of coils by the detection unit.

A drive control device for a motor includes an input terminal, an output terminal, an inverter circuit, a first switch unit, a capacitor, a diode, a rectifier circuit, a photo coupler, a second switch unit, and a voltage detector. The inverter circuit converts a direct current voltage into an alternating current voltage, and outputs the alternating current voltage to the output terminal. The first switch unit shorts the output terminal based on a control signal. The capacitor is connected to the input terminal, and is charged by a direct current voltage. The diode is connected between the input terminal and the capacitor. The diode limits a direction where a charge current for charging the capacitor flows. The rectifier circuit rectifies an induced voltage, which is generated in the motor, and outputs a rectified voltage. The photo coupler converts the rectified voltage into an optical signal, and thereafter, converts the optical signal into a converted signal. The second switch unit outputs the control signal based on the converted signal. The voltage detector detects whether the direct current voltage is input to the input terminal, and determines whether to negate the control signal.

A method for controlling switched reluctance machine (SRM) utilizing a SRM control system. The method allows for adaptive pulse positioning over a wide range of speeds and loads. An initial rotor position is provided for the SRM utilizing an initialization mechanism. A pinned point on a phase current waveform is defined during an initial current rise phase of the current waveform. A slope of the current rise is determined as the current waveform reaches the pinned point. The slope is then fed to the commutation module of the SRM control system. An error signal from calculated inductance or current slope is used as an input to a control loop in the SRM control system. The time determining module determines an optimum time signal to fire a next pulse. The optimum time signal is fed to the SRM for turning the plurality of SRM switches to on and off states.

In some examples, an apparatus includes a filter having first and second inputs, a current signal input, and an output. The apparatus also includes a speed observer having a voltage signal input, a current signal input, and an output, the output of the speed observer coupled to the second input of the filter. The apparatus also includes a ripple counter having an input and an output, the input of the ripple counter coupled to the output of the filter. The apparatus also includes a ripple processor having first and second inputs, and an output, the first input of the ripple processor coupled to the output of the ripple counter, the second input of the ripple processor coupled to the output of the speed observer, and the output of the ripple processor coupled to the first input of the filter.

Monitoring conditions of an electric motor using stator current and voltage signals from power supplied to the motor is disclosed herein. The stator voltage and current signals may be used to calculate instantaneous power values which may be used to calculate slip. The slip may be used to monitor for a locked rotor condition during startup of the motor. The slip value may be used to provide thermal protection to the electric motor.

A motor control circuit for controlling an electric motor may include at least one switching device configured to receive, from a pulse modulation device, a pulse modulated signal and output, based on the pulse modulated signal and to the electric motor, a current. In some examples, a frequency of the pulse modulated signal is below a threshold frequency. The motor control circuit may also include a transient detection circuit configured to detect a current transient, and responsive to detecting the current transient, output a pulse. The motor control circuit may further include a pulse counter configured to update, based on the pulse, a value indicative of a position of a rotor of the electric motor; and output the value indicative of the position of the rotor.