A method of controlling a brushless permanent-magnet motor having a phase winding and a rotor, includes applying voltages of first and second opposing polarities to the phase winding when the rotor is oscillating about a parking position, measuring a plurality of first times, each first time including a time taken for current flowing through the phase winding in response to an applied voltage of the first polarity to exceed a threshold and measuring a plurality of second times, each second time including a time taken for current flowing through the phase winding in response to an applied voltage of the second polarity to exceed the threshold. The method includes determining which of an average magnitude of the plurality of first times and an average magnitude of the plurality of second times has the smaller average magnitude, and determining an amplitude peak of the plurality of times having the smaller average magnitude. The method includes using the amplitude peak to calculate a time window, setting a timer corresponding to the time window at a subsequent determined amplitude peak, and applying a drive voltage to the phase winding during the time window.

The invention relates to a method for operating an asynchronous machine (1) comprising a rotor (3) and a stator (2), in which a torque of the asynchronous machine (1) is adjusted by specifying a desired magnetic flux of a surrounding magnetic field of the stator (2) and specifying a desired slip between a rotational speed of the rotor (3) and the rotational speed of the surrounding magnetic field. According to the invention, at least in the load condition and when a rotary frequency of the surrounding magnetic field of the stator is equal to zero, the desired magnetic flux and/or the desired slip with constant torque is changed in such a way that an actual rotary frequency of the surrounding magnetic field is not equal to zero.

Reduced is occurrence of hunting in which a power factor corrector continuously turns on and off alternately for a short period of time. A power factor correction controller turns on a power factor corrector if a parameter value for an input current into the power factor corrector is greater than or equal to a first threshold, and turns off the power factor corrector if the parameter value is smaller than or equal to a second threshold below the first threshold. Through a predetermined time period from a moment when the power factor corrector is switched either from on to off or from off to on, the power factor correction controller maintains a state of the switched power factor corrector, regardless of the parameter value.

The motor control apparatus includes: a setting unit configured to set a limit value of coil current flowing through a coil of a motor; a current supply unit configured to supply the motor with the coil current in a range not exceeding the limit value set by the setting unit; a detection unit configured to detect a current value of the coil current; and a comparison unit configured to compare an average value of the current value detected by the detection unit over a predetermined time period with a first threshold value. When the average value has exceeded the first threshold value, the setting unit updates the limit value in a decreasing manner.

A motor driving device and an air conditioner including the same are disclosed. The motor driving device includes a rectifier to rectify input AC power, a boost converter to boost power rectified by the rectifier, a capacitor to store a pulsating voltage from the boost converter, an inverter comprising a plurality of switching elements, the inverter transforming AC power, using a voltage across the capacitor, and outputting the transformed power to a motor, a regenerative power consuming unit arranged between the capacitor and the inverter, to consume regenerative power from the motor, and a switching driving unit to output a switching control signal to a switching element in the regenerative power consuming unit while outputting an operation control signal to an inverter controller when the voltage across the capacitor is equal to or higher than a predetermined voltage.

An electric motor controller system for modulating requested motor torque via oscillating the instantaneous torque, including a bi-stable torque controller; a proportional-integral (PI) velocity controller a proportional-integral-differential (PID) position controller; and sinusoidal zero-velocity table mapping.

A system is provided for controlling rotation of a rotor relative to a stator of a stepping motor, linear motor, or the like. A driver pulse generating electronic device outputs driver pulses to a driver of the motor for causing discrete steps of rotation or linear movement of the rotor relative to the stator to control rotation or linear movement, direction of rotation or linear movement, and speed of rotation or linear movement of the rotor relative to the stator. The driver pulse generating electronic device is configured such that a signal proportional to a difference between a command input signal provided by a controller and an encoder signal of actual rotor position of the motor is used to determine when a next driver pulse is output from the driver pulse generating electronic device. A method is also disclosed.

A converter for an air conditioning system includes a rectifier section configured to receive a multiphase, AC input voltage; a voltage regulator section coupled to the rectifier section, the voltage regulator section configured to control a DC output voltage across a positive DC bus and a negative DC bus; and a controller in communication with the rectifier section and the voltage regulator section, the controller configured to control the converter in a first mode or a second mode in response to a transient detected in the converter.