Abstract: A power conversion apparatus includes: a line breaker that is connected in series to a direct-current power supply; a first capacitor that is connected in parallel to the direct-current power supply through the line breaker; a discharge circuit that includes a resistor and a first switching circuit connected in series and is connected in parallel to the first capacitor; a power converter for driving a synchronous machine; a second capacitor that is connected in parallel to a direct-current side of the power converter; a second switching circuit that is connected in series between the first capacitor and the second capacitor; and a control circuit for controlling the discharge circuit. The control circuit controls the discharge circuit on the basis of the voltage of the first capacitor and the voltage of the second capacitor.

Abstract: A vehicle includes a power storage device, a motor generator, a converter for stepping up an output voltage from the power storage device, an inverter for driving the motor generator, and an ECU. The inverter includes switching elements. The switching elements have a characteristic that the withstand voltage of the switching elements decreases as the temperature of the inverter decreases. The ECU sets the stepped-up voltage, based on a temperature characteristic of the power storage device and a temperature characteristic of the inverter, so that the stepped-up voltage is increased within a range in which the stepped-up voltage does not exceed the withstand voltage. In this way, at low temperatures, deterioration of the power performance can be suppressed while the switching elements are protected.

Abstract: An inverter device may include a converter unit configured to receive single phase AC power to output DC power; a capacitor unit configured to absorb the DC power; an inverter unit configured to synthesize the absorbed DC power to output the drive power of a load; and a converter controller configured to control the converter unit based on the AC power and the output DC power of the converter unit, wherein the converter controller includes a converter gate signal generator configured to control a plurality of gates contained in the converter unit; and an input line harmonic voltage generator configured to output converter additional power having a predetermined multiple of the frequency of the fundamental frequency component of the AC power with the same size as that of the fundamental frequency component of the AC power to an adder connected to the input side of the converter gate signal generator.

Abstract: A booster circuit of a motor drive apparatus has at least two sub-booster circuits connected in series. Each sub-booster circuit includes a booster coil, a boosting switching element, a reducing switching element and an output capacitor, and outputs, by boosting an input voltage, a boosted output voltage. The booster circuit 20 outputs from its final stage sub-booster circuit a booster output voltage, a total boosting ratio of which is a product of sub-boosting ratios of the series-connected sub-booster circuits. Thus, the booster output voltage supplied to a motor drive circuit is prevented from falling even when high power output is required.

Abstract: This disclosure relates to a variable speed drive for driving a motor having a starting circuit. The variable speed drive adaptively generates motor voltages to reduce the likelihood of starting circuit intrusions.

Abstract: Embodiments of the invention provide methods of controlling a motor, such as a servo motor. One method can include monitoring a current temperature of the motor and a power stage of the motor substantially continuously and substantially in real-time. This method can include determining optimum settings for a first time interval to remove power and the second time interval to provide power in order to deliver maximum output while remaining below the maximum rated temperature of the motor. One method can include pulsing power to the motor for a second time interval after a first time interval has elapsed and tailoring pulse shapes of the power provided to the motor for the second time interval. One method can include calculating a maximum phase current based on the rotor shaft torque for each real-time speed of the motor that correlates to the maximum allowable current draw from the power supply.

Abstract: A control apparatus for an AC motor that drives and controls the AC motor includes a damping control unit that calculates a damping manipulated variable that suppresses a fluctuation in the capacitor voltage, wherein the damping control unit calculates a fluctuation rate of the capacitor voltage, calculates the damping manipulated variable based on the fluctuation rate and a predetermined value that is set as a value in a predetermined range around a maximum torque of the AC motor, generates a torque command or a current command of the AC motor based on the damping manipulated variable, and controls an inverter so as to change a current flowing in the inverter in a fluctuation suppressing direction with respect to a fluctuation in the capacitor voltage based on the torque command or the current command.

Abstract: A circuit for activating an electric motor in a work apparatus includes a main circuit having an electric motor, a rechargeable-battery pack, and an operating switch for activating the motor, and also a parallel branch to the battery pack and the operating switch. A capacitor is arranged in the parallel branch. To lower the electrical contact load on the operating switch, provision is made to arrange an electronic switch, which is connected in series with the capacitor, in the parallel branch. The series circuit which includes the capacitor and the electronic switch has a first and a second end. The ends form the only electrical power connection of the capacitor to the main circuit. The electronic switch in the series circuit will apply a supply voltage, which is provided by the battery pack, to the capacitor only after a period of time following closing of the operating switch has elapsed.

Abstract: Provided is an inverter-integrated electric compressor having high heat resistance, which is capable of suppressing thermal interference among a plurality of power devices. Specifically provided is an inverter-integrated electric compressor which comprises a built-in motor and a substrate provided with a motor drive circuit including an inverter, an electric component including the substrate being affixed in a housing space surrounded by a compressor housing, wherein a plurality of power semiconductor elements which constitute the motor drive circuit are disposed radially around a drive shaft of the motor in a plane crossing the drive shaft. For example, the planar shape of the power semiconductor element is formed into a rectangle, and a gap having a sectorial planar shape is formed between the power semiconductor elements adjacent to each other.

Abstract: A circuit switching element is provided that switches a step-up/step-down bidirectional chopper circuit, arranged between a DC bus and a power storage element, to a first chopper circuit or to a second chopper circuit, whose step-up and step-down characteristics are in a complementary relation. The first and second chopper circuits are used together at a time of charge and discharge. Accordingly, an AC motor drive device having mounted therein a power storage system is obtained, in which the power storage system can perform charge and discharge to and from the power storage element, regardless of a bus voltage and can increase energy use efficiency.

Abstract: A control device performs voltage conversion control on a voltage conversion circuit between a power supply and motor control circuits which control a plurality of motors. The control device includes sampling units for sampling a DC voltage after voltage conversion, target voltage setting units for setting target voltages VHT1 and VHT2 of the plurality of motors, selection unit for selecting a target voltage VHT to be converted by the voltage conversion circuit from a plurality of target voltages VHT1 and VHT2, generating unit for generating a sampling timing TS on the basis of a gate signal GS1 or GS2 of one of the motors with the target voltage which has not been selected, and control unit for performing the voltage conversion control using the DC voltage sampled by the sampling units at the sampling timing TS in response to each sampling timing request DS in the voltage conversion control.

Abstract: A construction machine comprises an electric motor/generator; an engine; an epicyclic gearing for rotating the electric motor/generator reversely when speed of a rotation output to a drive wheel is zero during running of the engine; a transmission configured to switch between a forward driving gear position and a backward driving gear position; and a controller for controlling the engine, the electric motor/generator and the transmission, based on at least an accelerator opening, and a state of charge in an electric storage device; the controller being configured to switch the forward driving gear position or the backward driving gear position to a direction opposite to a direction in which the construction machine is moving, and cause the electric motor/generator to generate reverse torque in a power running mode, when the electric storage device is in a fully charged state and the accelerator has been pressed down by a driver.

Abstract: A control system for an electric machine, the control system including a position sensor and a drive controller. The drive controller generates one or more control signals for exciting a winding of the electric machine in response to edges of a signal output by the position sensor. Moreover, the drive controller generates control signals in response to an edge that occurs within a time window. The time window starts at a time when control signals are generated and has a length less than the electrical half-cycle period.

Abstract: Single-phase voltage operation techniques are provided for a three-phase drive system. A drive system may include a rectifier configured to couple to a three-phase AC voltage source. The rectifier may be configured to convert AC voltage from the three-phase AC voltage source to a direct current (DC) voltage. The drive system may also include a controller configured to send a plurality of switching signals to a plurality of switches in the rectifier such that the plurality of switching signals minimizes a current provided to the rectifier when only a single-phase of the three-phase AC voltage source is available.

Abstract: A boost converter control apparatus for controlling a motor drive system which is provided with a boost converter disposed between an electric power converter and a direct current power supply, the boost converter boosting a direct current voltage of the direct current power supply and supplying it to the electric power converter, is provided with: an operating device provided with a proportional element, an integral element and a derivative element, the derivative element being configured as a bandpass filter, the operating device calculating a PID controlled variable corresponding to an electric current command value of the boost converter for maintaining an output voltage of the boost converter at a command value of an inter-terminal voltage VH of a smoothing condenser; and a controlling device which is configured to control the output voltage of the boost converter on the basis of the calculated PID controlled variable.

Abstract: Motor control circuits and associated methods to control an electric motor provide an ability to synchronize a rotational speed of the electric motor with an external clock signal, resulting in reduced jitter in the rotational speed of the electric motor.

Abstract: A power supply system of a transport system includes: a direct-current intermediate circuit; a motor bridge connected to the direct-current intermediate circuit, for supplying power between the direct-current intermediate circuit and the motor that moves the transport appliance; and also an energy storage and a direct-current converter based on indirect power transmission connected between the energy storage and the direct-current intermediate circuit, for controlling the power supply between the energy storage and the direct-current intermediate circuit. The direct-current converter based on indirect power transmission includes: a controllable solid-state switch, for disconnecting the power supply occurring from the energy storage.

Abstract: An electric motor vehicle includes an inverter, an electric motor, a power supply circuit, and a controller. The power supply circuit converts alternating current that the electric motor serving as a generator generates into direct current. The controller is supplied with electric power from the power supply circuit and controls switching elements of an inverter. The power supply circuit includes a transformer and a voltage regulator. The transformer includes a primary coil and a secondary coil, and the primary coil is connected to the electric motor. The voltage regulator adjusts the output of the secondary coil of the transformer to a predetermined direct-current voltage.

Abstract: A control apparatus in a motor drive system includes a magnet temperature acquiring device and a step-up ratio determining device. The magnet temperature acquiring device is configured to estimate or detect a temperature of a permanent magnet provided in a rotor or a stator of a motor of the motor drive system. The motor drive system includes a power supplying device to output direct current voltage, and a voltage step-up device to increase, at a certain step-up ratio, the direct current voltage which is output from the power supplying device. The step-up ratio determining device is configured to determine the certain step-up ratio in accordance with the temperature of the permanent magnet estimated or detected by the magnet temperature acquiring device.

Abstract: A power converting device includes a rectifying circuit that rectifies voltage of an alternating-current power supply; smoothing means that smoothes output voltage from the rectifying circuit; short-circuiting means that is disposed more closely to the alternating-current power supply than the smoothing means and that short-circuits the alternating-current power supply and controls at least one of electric current and voltage; a reactor that is disposed more closely to the alternating-current power supply than the short-circuiting means; one or more backflow preventing elements that prevent electric current from flowing backward from a load side toward the alternating-current power supply; commutating means for performing a commutation operation for causing electric current to flow toward a different path that is connected in parallel with the one or more backflow preventing elements; malfunction detecting means for detecting a malfunction of the commutating means; and switching control means that performs op

Abstract: The power supply system for supplying electrical power to a load is capable of delivering an output voltage to the load from an input voltage coming from an electric power network. The power supply system includes: at least two input terminals and at least two output terminals, the input terminals being adapted to be connected to the electric power network and the output terminals being adapted to be connected to the load, a converter capable of converting the input voltage into the output voltage, the converter being connected between the input terminals and the output terminals, and a device for limiting the homopolar current that is likely to flow between the electric power network and the load. The device for limiting the homopolar current comprises a transformer connected in parallel with respect to the converter, between the input terminals and the output terminals, the transformer having a first electromagnetic coil and a second electromagnetic coil.

Abstract: A surge current protection circuit, has a control unit having an output end, a photoelectric coupling and driving circuit, a silicon symmetrical switch having a control end, and a current-limiting resistor. The current-limiting resistor and the silicon symmetrical switch are parallel connected altogether and then serially connected to a load and an AC input, and the control end of the silicon symmetrical switch is connected to the output end of the control unit via the photoelectric coupling and driving circuit. The invention features low production cost, high reliability and improved power efficiency, and is capable of effectively suppressing surge current.

Abstract: An inverter device, a motor driving device, a refrigerating air conditioner, and a power generation system, which can reduce the recovery loss thereof, are obtained. A plurality of arms that can conduct and block current are provided. At least one of the plurality of arms includes: a plurality of switching elements each having a parasitic diode and being connected in series with each other; and a reverse current diode connected in parallel with the plurality of switching elements.

Abstract: An electrical control system having a direct current to direct current regulator receiving a direct current supply input, wherein the regulator outputs a controlled voltage direct current inverter power feed. Included is an inverter in electrical communication with the regulator and receives the controlled voltage direct current inverter power feed, the inverter outputs an alternating current motor power feed to a permanent magnet brushless direct current motor that outputs a shaft rotational speed and a back electromotive force. Also, a control is provided for regulating the controlled voltage direct current inverter power feed based upon criteria utilizing the back electromotive force or an auxiliary motor stator wire loop signal in conjunction with an optional voltage look-up table to substantially make the controlled voltage result in a reduction of a pulse width modulation switching frequency to further smooth and reduce harmonic of the alternating current waveform to increase motor efficiency.

Abstract: A system is disclosed for driving a DC motor (15) under conditions of a controlled average current. An inductive element may be arranged for connection in series with the DC motor. A switch (14) is preferably coupled to the inductive element for connecting and disconnecting a terminal of the inductive element from the voltage source. A diode may be arranged for connection in parallel with a combination of the inductive element and the DC motor arranged in series, with appropriate polarity so that current circulating through the inductive element circulates through the diode when the switch disconnects the terminal from the voltage source. A capacitor is arranged for connection in parallel with the motor, for limiting a resulting voltage over the motor or for storing charge depending on the embodiment of the invention. A device for measuring a current through the motor is provided, and a device (13) for controlling operation of the switch dependent upon the measured current in the motor is also provided.

Abstract: A power tool includes a housing, a brushless DC motor housed inside the housing, a power supply, a control unit, and an input unit such as a trigger switch actuated by a user. The control unit controls the commutation of the motor through a series of power switches coupled to the power supply. The control unit initiates electronic braking of the motor after occurrence of a condition in the input unit, such as trigger release or reduced speed, indicative of the power tool shut-down. A mechanism is provided to power the control unit for a predetermined amount of time after the detection of the condition from the input unit in order to complete the electronic braking of the motor.

Abstract: A drive unit has a control power supply, a power source (1) producing direct current to one or more inverters (2), an energy storage (C) arranged at the power source (1) output, and a discharge circuit (8,10) for discharging the energy stored in the energy storage (C) and including a power resistor (8). Switches (5, 6) are arranged between the power source (1) and energy storage (C) and in default position when there is no control power in the drive unit. The power source (1) is disconnected and the energy storage (C) discharged through the power resistor (8) when the switches (5, 6) are in default position.

Abstract: A method is disclosed for adjusting a voltage of a DC-voltage intermediate circuit in a battery system having a battery and a drive system. The battery is configured to output one selectable output voltage from n+1 different output voltages. In a first step of the method, an actual value of the voltage of the DC-voltage intermediate circuit is determined, and is then compared with the various output voltages of the battery. A first selected output voltage of the battery, which is the highest voltage of those output voltages of the battery which are less than the actual value of the voltage of the DC-voltage intermediate circuit, and a second selected output voltage of the battery, which is the lowest voltage of those output voltages of the battery which are higher than the actual value of the voltage of the DC-voltage intermediate circuit, are then selected.

Abstract: An electronically commutated pump motor circuit comprises an input configured, to receive at least a first range of voltages, and a power conditioning circuit. The power conditioning circuit includes an active power factor correction circuit, coupled to the input. The power conditioning circuit is configured to receive the first range of voltages and automatically output to an electronically commutated motor (optionally a pump motor) a substantially constant DC voltage for input voltages within the first range of input voltages, boosted with respect to a voltage received at the input, to thereby maintain a substantially constant motor shaft speed for any voltage within the first range of voltages.

Abstract: A driving device is electrically connected with an AC power and a brushless DC motor for a fan. The driving device includes a rectifier unit, a filter unit, a switch power conversion unit and a control unit. The rectifier unit receives the AC power and rectifies the AC power. The filter unit, electrically connected with the rectifier unit, filters the rectified AC power and generates a DC power. The switch power conversion unit, electrically connected with the filter unit and the brushless DC motor, receives the DC power and outputs a driving power to the brushless DC motor. The control unit is electrically connected with the switch power conversion unit and the brushless DC motor.

Abstract: A blower motor assembly having a variable speed motor that is suitable for replacing a PSC motor in a residential HVAC (heating, ventilation, and air conditioning) system. The blower motor assembly includes a variable speed motor and motor controller; a first power input for receiving a plurality of AC power signals from a control device for use in determining an operating parameter for the motor; and a second power input for receiving AC power from an AC power source for powering the motor controller even when no AC power signals are received by the first power input.

Abstract: Example embodiments disclose an Interior Permanent Magnet (IPM) machine system including an IPM machine including a nominal operating direct current (dc) bus voltage, and a controller configured to detect an operating dc bus voltage of the IPM machine and to control the IPM machine based on the nominal operating dc bus voltage and the detected operating dc bus voltage.

Abstract: A motor control device detecting short-circuit and disconnection faults of a power relay includes: a drive circuit of a motor; the power relay having first and second switching elements; a capacitor; a voltage detector detecting a voltage of the first switching element; a charger charging the capacitor; and a controller detects a short-circuit fault of the first and second switching elements according to the detection voltage when the first and second switching elements turn off after the charger charges the capacitor, detects a disconnection fault of the second switching element according to the detection voltage when the first switching element turns off, and the second switching element turns on and detects a disconnection fault of the first switching element according to the detected voltage when the first switching element turns on, and the second switching element turns off.

Abstract: Disclosed is a control device which performs voltage conversion control for a voltage conversion circuit between motor control circuits which control a plurality of motors and a power supply. The control device includes sampling means for sampling a DC voltage after voltage conversion, target voltage setting means for setting target voltages of the plurality of motors, selection means for selecting a target voltage to be converted by the voltage conversion circuit from among the plurality of target voltages, generation means for generating a sampling timing on the basis of a carrier signal of one of the motors having the unselected target voltage, and control means for performing voltage conversion control using the DC voltage sampled by the sampling means in response to the sampling timing for each sampling timing request of voltage conversion control.

Abstract: Motor drive apparatus and methods are presented in which a standby controller uses at least one switching device to power an inverter in a normal mode and to remove power from the inverter and other motor drive components during a standby mode for improved energy efficiency.

Abstract: An in-vehicle power supply system includes a DC power source, a steering power converter, a steering drive control unit, a plurality of voltage-reducing devices, and a voltage-reducing control unit. The steering power converter converts electric power supplied from the DC power source, and provides the electric power converted to a steering assist motor. The steering drive control unit is supplied with electric power from the DC power source, and controls the steering power converter. The voltage-reducing devices are coupled in parallel to each other between the DC power source and the steering power converter. Each of the voltage-reducing devices reduces a power source voltage of the DC power source and generates a reduced voltage when being operated. The voltage-reducing control unit determines operation state or non-operation state of each of the voltage-reducing devices such that at least one of the voltage-reducing devices is in operation at a time.

Abstract: The present invention relates to an EC motor assembly (1) having an electronically commutated, permanent magnet-excited DC motor (M) with an upstream commutation electronic unit (2) that is supplied with a DC link voltage (UZK) via a DC link (8). The DC link (8) can be connected directly to a solar cell generator (12) via a first voltage input (10) on one hand, and on the other, to a grid voltage (UM) via a controllable power supply unit (14) and a second voltage input (16). The DC link voltage (UZK) is variably specified based on a respective available photovoltaic voltage (UPV) of the solar cell generator (12). The power supply unit (14) can be regulated with respect to the output voltage thereof to adapt to the respective DC link voltage (UZK).

Abstract: There are provided a command speed calculation means (101) for outputting a command speed (?r) from a base speed (?b) and a ratio gain (?), reference speed generation means (108) calculating a reference speed (?a) so as to follow the command speed (?r) based on the command speed (?r), control deviation calculation means (103) for outputting a control deviation (e) from a speed deviation (?e) and a speed deviation correction value (?ec), speed control means (104) for outputting a compensation torque (?m) for decreasing the control deviation (e), speed deviation correction means (105) for calculating the speed deviation correction value (?ec) from at least the compensation torque (?m), command torque calculation means (107) for outputting a command torque (?r) from at least the compensation torque (?m) and ratio calculation means (102) for calculating the ratio gain (?) from the speed deviation (?e).

Abstract: A power train for a transport vehicle is provided. The power train includes an electric motor comprising a shaft, a stator and a rotor, a power supply system receiving direct input voltage and delivering a polyphase voltage to the motor. The system has a modulation factor equal to the voltage amplitude of each phase of the motor divided by the direct input voltage, and includes a sensor for the rotational speed of the rotor.

Abstract: Embodiments of the present invention provide novel techniques for using a switched converter to provide for three-phase alternating current (AC) rectification, regenerative braking, and direct current (DC) voltage boosting. In particular, one of the three legs of the switched converter is controlled with a set of pulse width modulation (PWM) control signals so that the input AC phase having the highest voltage is rectified and one of the switches in the two other legs is turned on to allow for added voltage. This switching activity allows for voltage from multiple AC line mains to be combined, resulting in an overall boost of the DC voltage of the rectifier. The DC voltage boost can then be applied to the common DC bus in order to ameliorate voltage sags, help with motor starts, and increase the ride-through capability of the motor.

Abstract: A microCHP unit including at least one pump (20) and/or fan for circulating a cooling fluid or air through the microCHP unit in normal operation. The microCHP unit comprises an electric power source (32) that is independent from the mains power supply. It also comprises a voltage converter (42) or inverter (44) or both connected between the independent power source (32) and the cooling pump(s) (20) and/or fan(s) (28) of the microCHP unit for converting a supply voltage from the independent electric power source (32) to a different voltage for operating the pump(s) (20) and/or fan(s) (28). A controller (34) is provided to cause the cooling pump(s) 20 and/or fan(s) (28) to operate in the absence of mains power. A charging device (48) is provided to recharge the independent power source (32) when the mains power supply is available.

Abstract: An LED driver system including an input receiving a rectified AC conductive angle modulated voltage on a rectified node, a converter, a low-pass filter, and AC detector, and a driver network. The converter is to the rectified node and includes a power switching device coupled to a switching node, in which the power switching device is controlled to convert the rectified AC conductive angle modulated voltage to an output voltage and output current. The low-pass filter is configured to filter voltage of the switching node to provide a filtered voltage. The AC detector receives the filtered voltage and provides a current sense signal indicative thereof. The driver network controls duty cycle of the power switching device based on the current sense signal.

Abstract: A rectifier connected with an AC source through a reactor, a plurality of capacitors connected in series between output terminals of the rectifier, first switching means connected between one input terminal of the rectifier and a connection point of a plurality of capacitors, second switching means connected between the other input terminal of the rectifier and the connection point of a plurality of capacitors, and a plurality of diodes connected with the plurality of capacitors in inverse-parallel are provided.

Abstract: An adjustable frequency drive includes a base having a first portion and a second portion, and an active front end converter disposed on the base. The converter includes an input, an output, and a plurality of first electronic switches electrically connected between the input and the output. An inverter is disposed on the base and includes an input electrically connected to the output of the active front end converter, an output, a plurality of capacitors disposed on the first portion of the base and electrically connected to the input of the inverter, a plurality of second electronic switches disposed on the second portion of the base and electrically connected between the input and the output of the inverter, and a heat pipe assembly. The inverter is structured to provide a single, three-phase output structure.

Abstract: A control apparatus for an AC electric motor vehicle including a converter that converts an AC voltage input from an AC overhead wire via a transformer into a DC voltage, an inverter that converts the DC voltage into an AC voltage, and a motor that is driven and controlled by the inverter includes: torque-command calculating units that calculate a torque command value of the motor and output the torque command value to the inverter; and a static inverter that supplies electric power to a load mounted on the AC electric motor vehicle.

Abstract: A motor device may include a motor unit and a converter unit. The motor unit may include a brushless DC motor, an inverter circuit, and an inverter drive circuit. The inverter circuit may supply a drive current to the brushless DC motor. The inverter drive circuit may supply a drive pulse signal to the inverter circuit. The converter unit may be connected to the motor unit. The converter unit may include an AD/DC converter and a microcomputer. The AC/DC converter may convert an AC voltage to a DC voltage to be supplied to the motor unit. The microcomputer may receive a digital control signal and may output an analog control signal. The inverter drive circuit may receive the analog control signal outputted from the microcomputer and may output a drive pulse signal to be supplied to the inverter circuit.

Abstract: A fan delay control circuit includes a fan connector connected to a fan of an electronic device, a power supplying module connected to the fan connector, and a rotational speed controlling module connected to the power supplying module. The power supplying module is connected to a fan power source and a stand-by power source. The power supplying module may continue to supply power to the fan when the electronic device including the fan is powered off. The rotational speed controlling module includes a square wave generation circuit which generates a square wave signal to control a rotational speed of the fan even when the electronic device is powered off.

Abstract: Embodiments of controllers for electric motors, and methods of operation for the same are disclosed. More particularly, the controllers and methods of operation are for motors designed to operate so as to reduce Back EMF.

Abstract: An AC-AC power converter supplies AC power to an AC motor having a plurality of motor windings and a case connected to a ground. The AC-AC power converter architecture includes an asymmetric phase shift autotransformer/rectifier unit (ATRU) that converts an AC input to a DC output, wherein the asymmetric phase shift ATRU generates a common-mode AC voltage across the asymmetric phase shift ATRU. The common mode voltage is diverted to ground through motor case parasitic capacitance via a common-mode voltage pull-down circuit connected between each phase of the ATRU AC input and the ground.

Abstract: A circuit arrangement is provided for supplying an electric drive, to which at least two electric energy sources can be connected. At least one of the at least two electric energy sources supplies at least intermittently the electric drive by way of at least one actuating element. At least one electric energy source can be disconnected from the electric drive by way of a switch. Furthermore, a method for operating the circuit arrangement, as well as a motor vehicle including the circuit arrangement, are provided.