Disclosed is a drain pump driving apparatus and a laundry treatment machine including the same. The laundry treatment machine includes: a drain pump driving apparatus configured to drive a drain pump, wherein the drain pump driving apparatus includes: a motor to drive the drain pump; an inverter to convert a direct current (DC) power to an alternating current (AC) power by a switching operation, and output the converted AC power to the motor; an output current detector to detect an output current flowing to the motor; and a controller configured to control the inverter, wherein the controller is further configured to calculate a speed of the motor based on an output current, and calculate a lift, which is a difference between a water level of a water introduction part through which water flows into the drain pump and s water level of a water discharge part for discharging water from the drain pump, based on the calculated speed.

A motor control circuit with power factor correction capabilities that optimizes the voltage and current load applied to an electric motor for different motor speeds and torque levels. The preferred motor control circuit includes a power factor correction circuit and a step down conversion circuit through which current passes before it reaches the motor. A microprocessor preferably monitors the current supplied to the motor and the motor's speed. If the microprocessor determines that the current supplied to the motor is too high, it can reduce the level of current by either using a pulse width modulation (PWM) digital-to-analog control circuit to instruct the power factor correction circuit to reduce current or it can use a PWM digital control circuit to instruct the step down conversion circuit to reduce current. An output voltage limiter circuit can be used to detect the voltage of current supplied to the motor and turn off current to the motor if the voltage is above a predetermined level.

A drive circuit for driving an electronically commutated motor contains a DC voltage intermediate circuit, and an inverter which is connected to the latter and has a bridge circuit containing a plurality of transistors, to which the motor phases of a motor configuration containing the motor can be connected. For detecting an insulation fault in the motor configuration, a positive or negative transistor of the inverter is switched on, while all other transistors of the inverter are switched off before all transistors of the inverter are switched off. A motor phase voltage of a selected motor phase of the motor phases with respect to a reference potential is then captured, while all transistors of the inverter remain switched off in order to determine whether there is an insulation fault on the motor phase on a basis of a voltage profile of the motor phase voltage.

The disclosure relates to a method for reducing the torque ripple and noise evolution in an EC motor with single-phase feed by buffer-storing electrical energy in the EC motor, which is embodied with a power factor correction circuit (PFC) having a capacitor (Cz) at the power supply system input for a specific power supply system AC voltage UN, wherein the capacitance of the capacitor is dimensioned such that when the power supply system AC voltage UN is applied, a pulsating DC voltage is generated in a link circuit (Z), wherein the pulsating electrical energy generated as a result is stored by means of a primary regulation of the id current component as magnetic energy in the EC motor at least for a predefined time period.

Provided is a power conversion controller in which variation in reactive power among power conversion controllers can be inhibited while maintaining the running performance of vehicles. The power conversion controller includes a power factor setter that sets a power factor based on a detection value of an overhead line voltage, and a calculator that calculates a reactive current command value by multiplying an active current command value by a tangent of a power factor angle of the power factor. The power factor setter sets a reference value set in advance as the power factor if the detection value is within a reference range, sets a value smaller than the reference value as the power factor if the detection value is below the reference range, and sets a value larger than the reference value as the power factor if the detection value is beyond the reference range.

An electric motor assembly includes a stator, a rotor, a motor housing, a rotatable shaft, a radial fan, and an air scoop. The motor housing at least partly houses the stator and rotor and presents an exterior motor surface. The rotatable shaft is associated with the rotor for rotational movement therewith, with the rotatable shaft extending along a rotational axis. The radial fan is mounted on the rotatable shaft exteriorly of the motor housing and is rotatable with the shaft to direct airflow in a radially outward direction. The air scoop extends radially outwardly relative to the radial fan and axially to receive radial airflow from the radial fan and turn the airflow axially to flow along the exterior motor surface. The air scoop includes spaced apart axially extending airflow vanes to guide the airflow as the airflow is turned axially.

A power conversion device is configured to output on/off signals for switching on and off respective semiconductor switching elements of an inverter configured to invert a DC voltage output from a DC power supply into three-phase AC voltages so that, out of a plurality of voltage vectors defined so as to correspond to patterns of the on/off signals, the second closest voltage vector and the third closest voltage vector in phase to a current vector that is based on currents supplied as a result of output of the three-phase AC voltages from the inverter are formed.

A control apparatus includes a drive circuit unit to which regenerative electric power is input, a discharge resistance unit parallel-coupled to the drive circuit unit, to which the regenerative electric power is input from the drive circuit unit, and, when a voltage value of the regenerative electric power exceeds a threshold value, consuming electric power, a second converter circuit unit parallel-coupled to a first converter circuit unit and converting and outputting an alternating current into a direct current, a step-down circuit unit stepping down and outputting a voltage of the current output from the second converter circuit unit, an energization control circuit unit actuated by the direct current and controlling the drive circuit unit, and a regenerative electric power supply unit having a regenerative diode coupled to the discharge resistance unit and outputting a direct current of the regenerative electric power to the step-down circuit unit.

A direct-current power supply apparatus includes: a reactor having one end connected to an alternating-current power supply; a bridge circuit, connected to an opposite end of the reactor, converting an alternating-current first voltage output from the alternating-current power supply into a direct-current voltage; and a current detector detecting an alternating current flowing between the alternating-current power supply and the bridge circuit. The reactor reduces an inductance in accordance with an increase of the alternating current and, when the alternating current exceeds a first current, has an inductance lower than one third of an inductance at which a current does not flow in the reactor. The bridge circuit performs an active operation when the detection value of the alternating current is larger than or equal to the first current and performs a passive operation when the detection value of the alternating current is lower than the first current.

A power converting apparatus includes: a reactor that includes a first terminal and a second terminal, the first terminal being connected to an alternating-current power supply; a bridge circuit that is connected to the second terminal of the reactor, includes at least one or more switching elements, and converts an alternating-current voltage output from the alternating-current power supply into a direct-current voltage; a power-supply current detecting unit that detects a current from the alternating-current power supply; and a control unit that controls ON and OFF of the switching elements depending on a current value detected by the power-supply current detecting unit, in which two or more current thresholds for controlling ON and OFF of the switching elements are included.