Abstract: A power supplied by an AC power supply is used as an input to a rectifying circuit, and an output of the rectifying circuit is used as an input to a smoothing capacitor having a capacitance of about 1/100 of the capacitance of conventionally used capacitance. The capacitor is provided between a positive electrode node and a negative electrode node located between bus lines of output of rectifying circuit. Diodes constituting a rectifying circuit are connected respectively with phase outputs of an inverter. The rectifying circuit is connected to the negative electrode node through a capacitor. The rectifying circuit is connected such that an electric current flows only in the direction from an output of the inverter to the capacitor. The load is connected in parallel with capacitor.

Abstract: A distributed-arrangement linear motor in which stators are arranged in a distributed manner and a method of controlling the distributed-arrangement linear motor are provided. The linear motor 1 is a linear motor in which a stator and a movable member are relatively movable, wherein the stator and the movable member respectively have periodic structures in which plural kinds of poles of the stator and the movable member (12a, 12b, 12c) (22a, 22b, 22c) which magnetically act each other and arranged periodically subsequently in an order according to the arrangement in a direction of the relative motion therebetween; a plurality of stators are arranged in a distributed manner in the direction of the relative motion; a distance D1, D2 between adjacent stators is not more than a length Lmv of the movable member; the pole of the stator is formed of a coil 11; and a current control unit that controls current to be supplied to the coil based on the distance between the stators is provided.

Abstract: Method and device for operating an asynchronous motor having increased efficiency. According to the invention, ranges for a motor size of the asynchronous motor are specified. In addition, a value of the motor size is calculated depending on at least one measurement value of a measurement parameter during the operation of the asynchronous motor, wherein the respective calculated value of the motor size is allocated to one of the ranges. Furthermore, a control parameter is changed depending on the range to which the calculated motor parameter is allocated to provide an optimised control parameter such that the control parameter is changed beginning from a starting value specified for the respective range of the motor size until a predetermined criterion for a specific motor size is reached. Furthermore, the optimised control parameter is stored as a support point of a continuous optimal characteristic curve for the control parameter depending on the range to which the calculated motor size is allocated.

Abstract: An electronic circuit comprises at least one semiconductor switch mounted with its switching path in series with an inductive load to be triggered, and at least one freewheeling element that interacts with the semiconductor switch during switching phases and is also mounted in series with the load. A control unit controls a control connection of the semiconductor switch with a variable control current as a function of the time profile of a voltage measured at the freewheeling element and/or as a function of the time profile of the voltage measured at the switching path. A method for triggering a semiconductor switch of such a circuit, triggered by a variable control current for switching, the control current predefined as a function of the time profile of a voltage measured at the freewheeling element and/or as a function of the time profile of the voltage measured at the switching path.

Abstract: Complete drive system, called motor-drive unit, for use in remote locations with limited radial space like downhole, narrow tunnels, pipelines and other applications with similar conditions. Given the spatial limitations the unit must have elongated shape. It includes a number of motors connected mechanically in series and a lower number of inverters, driving groups of the motors so that load is equally distributed along axis of the unit. Motors within each group can be electrically connected in series or in parallel. The motor-drive unit is supposed to be fed by DC voltage via a cable with length up to several km; therefore, it includes a buck converter for stabilization of voltage inside the unit and a power-line communication module to be controllable from the surface.

Abstract: A hybrid powertrain system has a high-voltage electric circuit including a high-voltage battery and a DC link coupled to first and second inverters electrically connected to first and second torque machines. A method for operating the hybrid powertrain system includes receiving a motor torque command for the second torque machine, determining a preferred DC link voltage for achieving the motor torque commanded from the second torque machine, selectively interrupting electric power flow between the high-voltage battery and the DC link to achieve the preferred DC link voltage.

Abstract: The present invention relates to a motor controller employing bootstrap-capacitor supplies and in particular to the situation where the bootstrap supplies have to be charged, while the motor controller is connected to a spinning and energized motor. The present invention introduces a method of recharging based on choosing a recharging sequence from a set of recharging sequences, where the choice depends on the state of the connected motor and in particular on the back-EMF voltages of the motor.

Abstract: According to one embodiment, four VVVF main circuit inverters for supplying electric power to drive a permanent-magnet synchronous motor are packaged into one unit. The four VVVF main circuit inverters are configured as a 4-in-1 inverter unit which shares a cooling mechanism for radiating heat generated due to power supply operation for the permanent-magnet synchronous motors to outside. A 2-in-1 semiconductor device package in which two semiconductor elements to convert electric power are packaged into one unit to be able to drive a permanent-magnet synchronous motor is contained in the 4-in-1 inverter unit. Thereby, individual control of inverters and reducing the size of the entire apparatus can be achieved for the electric-vehicle control apparatus.

Abstract: A method and arrangement in connection with an electric drive system are provided. The electric drive system includes an intermediate circuit with two or more supply units and two or more inverter units connected thereto, and an electric machine having two or more three-phase windings galvanically separated from each other. Two or more inverter units are connected to the three-phase windings. The arrangement also includes first main circuit switches to galvanically separate each supply unit from a supply, second main circuit switches to galvanically separate each supply unit from the intermediate circuit, first intermediate circuit switches to galvanically separate each inverter unit from the intermediate circuit, and second intermediate circuit switches to galvanically separate each inverter unit from the electric machine.

Abstract: A power converter and an air conditioner having the same, in which the power converter includes a rectifying unit configured to rectify an input AC current and an interleave converter that has a plurality of converters and that is configured to convert rectified output from the rectifying unit to DC power and output the converted DC power. The power converter also includes a capacitor connected to an output terminal of the interleave converter, and a converter controller configured to control the interleave converter. The converter controller controls the interleave converter by calculating a load level of both terminals of the capacitor and changing a number of operating converters in the plurality of converters of the interleave converter based on the determined load level of both terminals of the capacitor.

Abstract: Back electromotive force (BEMF) of a brushless DC (BLDC) motor may be determined when using continuous sinusoidal drive by computing the voltage to common (ground) of each phase (3) thereof when a phase current is substantially zero. These phase voltages may be computed from the DC supply voltage and the duty cycle of the pulse width modulation (PWM) drive to each of the motor phases. From the three phase voltages computed at a zero phase current occurrence, each coil voltage may be calculated. The BEMF of that coil is substantially equal to the coil voltage when at zero current. The phase voltages, when computed at a zero current instance, may be used in determining the BEMF. Once the BEMF is determined it may further be used to regulate the motor speed using a K factor of the BLDC motor.

Abstract: To provide a disk drive capable of inhibiting the occurrence of acoustic noise caused by a voltage pulse when the head is retracted using a speed control method using voltage obtained by rectifying a back electromotive force after the power source has been cut off from the rotation of a spindle motor. Retraction control circuit is used to control the on and off modes of transistors in accordance with the speed of VCM. The voltage across VCM becomes a voltage that can be regulated with VCM voltage control circuit. At this time, voltage is supplied to the terminals based on the voltage of ISO5V that is the rectified voltage of the back electromotive force of the spindle motor and the pulsating voltage is synchronized and produced at both terminals. As a result, the potential difference across VCM is such that the pulsating voltage is negated and acoustic noise is inhibited.

Abstract: Methods and systems for controlling an electric motor are provided herein. The system is configured to be coupled to a power supply. The electric motor system includes a rectifier, an electric motor, and a microcontroller. The rectifier is configured to convert an alternating current (AC) voltage input to a direct current (DC) voltage. The microcontroller is configured to extract power from a generator device.

Abstract: The present invention provides a motor drive control device provided with a shutoff circuit employing semiconductor relays and configured to drive a motor by a duty ratio control of an inverter, which stably drives the motor even in an operation state that drive duty ratio of phases are uneven. In the motor drive control device, output lines of three phases of the inverter circuit are connected to phases of the motor and further connected to a booster circuit, an output boosted by the booster circuit at a time of drive of the motor is distributed to semiconductor relays connected to respective phases of the motor, and furthermore, a switching circuit for stopping actuation of the booster circuit to shut off drive of the motor, is interposed in a line for supplying an electric power to the booster circuit.

Abstract: A combined battery charger and motor driver circuit assembly includes a rechargeable battery, a traction motor configured to accept a pulse-width-modulated (PWM) drive, a PNP transistor array, a charging source of chopped and rectified DC, and a control circuit configured to apply a discrete PWM drive signal to the gate of each transistor in the PNP transistor array.

Abstract: A circuit for controlling a load current through a coil is connected to an output port of a transistor H-bridge that includes two low side transistors and two high side transistors. A current sense circuit is coupled to the H-bridge and configured to provide a representation of the load current provided by the output port. A current regulator is configured to generate a modulated signal dependent on the representation of the load current and a current set-point. The modulated signal has a duty-cycle. A gate control logic drives the individual transistors of the H-bridge on and off in accordance with the modulated signal. A direction signal provides the load current to the coil. The direction signal determines the direction of the load current. An over current detection circuit is coupled to each individual transistor and is configured to signal an over-current by providing an active over-current failure signal when a transistor current through the respective transistor exceeds a respective maximum value.

Abstract: The invention discloses a reciprocal radial field electric machine based on the soft magnetic attraction principle, characterized by a plurality of active elements organized as a bi-dimensional cylindrical machine matrix and fed sequentially by an external power converter in order to derive a motoring or generation effect. The machine is comprised of a fixed stator matrix featuring salient poles and electrical coils, and a mobile rotor matrix featuring salient poles. The machine works on the principle of time integration of the discrete actions performed by its active elements. The bi-dimensional matrix organization of the active elements and the algorithms of their activation in both motoring and generation modes are key features for the functional cohesion of the machine. The design of this machine is based on a unique digital modeling method developed by the inventors, using exclusively the matrix calculus adapted to cylindrical matrices.

Abstract: Example embodiments disclose a drive system including a machine including a plurality of phases and configured to generate power based on a plurality of phase currents, each respectively associated with the plurality of phases and a direct current (DC) bus, operatively connected to the machine. The DC bus includes a high-side line, a low-side line, and an inverter including a plurality of switching systems, operatively connected between the high-side line and the low-side line, the plurality of switching systems, each configured to output a respective one of the plurality of phase currents. The drive system also includes a controller, operatively connected to the DC bus and the machine, the controller configured to determine if a failure exists in the drive system based on the plurality of phase currents and a DC bus voltage, the DC bus voltage being a voltage across the high-side line and the low-side line.

Abstract: The invention relates to a variable speed drive (1) connected upstream to an electric power grid (R) and downstream to an electric motor (M), the variable speed drive comprising notably a main casing comprising a base (14) and a main closure cover (15) closing on the base (14), a rectifier module (10), an inverter module (11), these modules being inserted inside the casing, and one or more bus capacitors (13). The main closure cover (15) comprises one or more openings (151) each traversed by a bus capacitor (13) and the variable speed drive comprises a secondary closure cover (17) fitting onto the main closure cover (15) and covering the said one or more bus capacitors (13).

Abstract: A polyphase electrical machine controlled by at least two parallel inverters, each including a number of branches equal to a number of phases of the machine and controlled by PWM. When detecting an inverter branch is faulty, the faulty branch is isolated and the phase in question is powered by each corresponding other inverter branch. The PWM is modified to make power switches of each other branch conductive in succession, without switching while absolute value of the current of the phase in question is greater than or equal to a threshold of 80% to 120% of (n?1)Imax/n, n is number of inverters and Imax is maximum magnitude of the phase current. It is thus possible to continue generating substantially sinusoidal voltages on each of the phases, while avoiding overdimensioning the power switches to ensure in event of a fault they can deliver currents of amplitude higher than in normal operation.

Abstract: A motor drive device has a driver circuit generating an output current for a motor and a control circuit controlling the drive circuit. The control circuit, when switching the driver circuit from a PWM-driving state to a linear-driving state, controls the timing of the switching such that the path of the output current does not change between before and after the switching, and in addition, in the middle of the switching, switches the driver circuit to a high-output-impedance state momentarily.

Abstract: A vehicle includes a polyphase, permanent magnet synchronous electric machine, DC and AC buses, a battery module, a traction power inverter module (TPIM), and a controller. The controller, which is in communication with the TPIM, executes a method to detect a fault condition, fixes the pulse width modulation (PWM) duty cycles of all phases of the electric machine to 50% such that all phases switch simultaneously, and applies a polyphase OPEN state to the AC bus in response to the detected fault condition. The controller then transitions to a polyphase SHORT state by automatically inserting an adjustable deadtime at each PWM switching transition of the TPIM over a calculated ramp duration, thereby transitioning from an initial deadtime to a minimum deadtime over the calculated ramp duration. The transition reduces peak overshoot of the negative d-axis current of the machine during the fault condition.

Abstract: A motor controller is provided that includes an inverter configured to drive an electric motor, a rectifier configured to rectify an alternating current (AC) input current and to output the rectified AC input current to the inverter, and a controller coupled to the inverter. The controller is configured to improve a power factor of the motor controller by controlling the AC input current based on a direct current (DC) link voltage measurement.

Abstract: A motor drive method of the invention is to drive a brushless motor having a rotor, a stator, and a hall element used as a position detecting sensor. While driving the brushless motor, when executing a correction process for a rotation speed of the rotor, the correction process is skipped for a predetermined number of times according to a position detection signal.

Abstract: An AC motor drive control device including: an inverter, having a plurality of switching elements subjected to on-off control, for converting a DC voltage to an AC voltage with a desired frequency to drive an AC motor; a motor opening contactor connected between the inverter and the AC motor; a switching operation beforehand detection unit for detecting a switching operation of the motor opening contactor prior to the contact or detach of main contacts and outputting a switching operation beforehand detection signal; and a control unit having an inverter control unit for performing the on-off control for the plurality of switching elements and switching control for the motor opening contactor, and controlling the inverter based on the switching operation beforehand detection signal.

Abstract: A motor drive apparatus includes an inverter which has an upper and lower arms each provided with a plurality of semiconductor switching devices and free-wheeling diodes connected in reverse parallel with respective ones of the plurality of semiconductor switching devices, wherein the semiconductor switching devices are controlled on and off to convert DC to AC, a short-circuiting unit which includes a selector switch between motor phase windings of a synchronous motor, the selector switch being opened and closed under the control of a command, and a dynamic braking control unit which, upon reception of a dynamic braking start command, performs control so as to turn on all of the semiconductor switching devices provided in either one of the upper and lower arms and to turn off all of the semiconductor switching devices provided in the other arm, and thereafter controls the short-circuiting unit so that the selector switch is closed.

Abstract: A motor control system includes: a power supply; a converter; an inverter; an alternating-current motor; and a control unit that drives the motor in any one of sinusoidal PWM control, overmodulation control and rectangular wave control through operation control of the converter and the inverter. The control unit starts step-up operation of the converter when a current vector of motor current of the motor on a d-q coordinate plane becomes a current phase corresponding to motor torque, at which a system loss is equal between before and after starting the step-up operation, while the control unit supplies the direct-current voltage, supplied from the power supply, to the inverter without stepping up the direct-current voltage by the converter and performs the rectangular wave control of the motor in a state where the current phase is an optimal current phase.

Abstract: An electric power steering apparatus includes an EPS actuator that applies assist force to a steering system, and an ECU that controls operation of the EPS actuator. The ECU includes an inverter device, a gate driver circuit, a gate driver power source, a microcomputer, and the like. The microcomputer switches assist control to assist stop control, based on an indication of a voltage decrease in the gate driver power source.

Abstract: Disclosed herein is an apparatus of a sensorless brush less direct current (BLDC) motor capable of rapidly driving the BLDC motor at a decreased speed.

Abstract: An switch array for use in a motor control circuit with a power source, controller and a motor includes a plurality of bidirectional switches positioned between the power source and the motor, wherein the bidirectional switches are PWM controlled by high speed control signals from the controller to provide power from the power source to the motor as desired, wherein the switch array is positioned substantially adjacent to the motor. The power source may be a three phase AC power source. The switches are preferably bidirectional gallium nitride (GaN) switches.

Abstract: A method serves for starting a polyphase electric motor which is operated in a star connection. The method conductively bridges at least one winding part of a phase of the motor and electrically disconnects the bridged winding part, in order in this manner, to supply a higher voltage to the remaining, electrically effective windings, and thus to increase the flow of current and thus the torque.

Abstract: In a motor drive apparatus for driving a three-phase AC motor, a first mounting part of a heat sink is formed along an end. A second mounting part is formed in a direction perpendicular to the first mounting part and includes a first column part and a second column part. Three motor relay FETs are mounted on the first mounting part. Six inverter FETs and two power relay FETs are mounted on the second mounting part. Leads of the FETs are electrically connected to an electric circuit substrate. Heat generated by the FETs is radiated to the heat sink through an insulating and heat radiating sheet. By thus arranging the FETs, the motor drive apparatus is reduced in size.

Abstract: In a motor control circuit, a switching element such as an FET for controlling a motor current and a current detection element for detecting the motor current are connected in series. One terminal of a temperature detection element is electrically connected to an electrical connecting section between the FET and the current detection element, and the other terminal of the temperature detection element is electrically connected to a temperature detection circuit.

Abstract: An inverter system for operating an electric motor includes an input port for providing an electrical voltage, a bridge inverter circuit connected downstream from the input port for generating an electrical alternating voltage for the electric motor based on the electrical voltage. The bridge inverter circuit has at least one half-bridge branch including switching elements configured to be open for transferring the electric motor into a freewheeling state, and a decoupling switching element designed for decoupling the at least one half-bridge branch in the freewheeling state of the electric motor from the input port, in order to suppress a reaction of the freewheeling electric motor on the input port.

Abstract: Proposed is a parallel inverter drive system including includes a plurality of inverter drives connected in parallel with each other, in which each inverter drive includes a switch; a PWM controller connected to the switch for controlling switching operations of the switch device according to a duty cycle signal; and a circulating current suppressor for collecting current information associated with the current of each inverter drive and a summation current, and generating an index according to the collected current information and the desired circulating current quantity. A zero-sequence voltage is generated for each phase of a three-phase voltage command according to the index and the voltage command and the operating mode of the inverter drive, thereby injecting the zero-sequence voltage into the voltage command with a feed-forward configuration so as to fix the voltage command. The PWM controller can generate the duty cycle signal according to the fixed voltage command.

Abstract: The present invention is directed to a method of estimating a motor rotation angle that does not affect precision of a detected angle of a crank angle sensor, which is an alternative sensor, when abnormality occurs in a resolver and a peripheral circuit, and performing a motor control without failure of an inverter or peripheral device. A vehicle system includes a motor, a resolver detecting a rotor rotation angle of the motor, a motor control circuit controlling the motor based on information on rotor rotation angle and torque command value, an engine connected to the motor through a crankshaft, and a crankshaft sensor detecting revolutions of the crankshaft, in which the motor control circuit estimates rotor rotation angle based on a variation rate of the number of revolutions of the crankshaft when abnormality of the resolver is detected, and performs a weak field control based on estimated rotor rotation angle.

Abstract: The invention relates to a brushless motor drive device that performs switching determination of energization modes of a three-phase brushless motor according to a sensorless method, and a drive method thereof. A pulse induced voltage induced in a non-energized phase of three phases by a pulse voltage is compared with a threshold to determine the switching timing of the energization modes. Here, by limiting a duty ratio of a voltage application to equal to or greater than a lower limit, a situation in which the pulse induced voltage is sampled while the pulse induced voltage is oscillating is avoided, and a situation in which the pulse induced voltage falls below a voltage detection resolution is avoided. As a result, determination of energization mode switching timing based on a pulse induced voltage can be performed more stably.

Abstract: A load control device to control current flow to an AC load includes a circuit having line-side switches and floating-neutral side switches, along with a controller connected to the circuit that is programmed to control the circuit so as to cause each of the line-side switches and each of the floating-neutral side switches to switch between an On condition or an Off condition to selectively operate the circuit in an active mode and a free-wheeling mode. A full phase voltage is provided to the AC load during the active mode and a zero voltage is provided to the AC load during the free-wheeling mode. The controller applies a modulating function to the circuit, so as to modulate a supply voltage to control a frequency and an average of a load voltage present across terminals of the AC load, thereby enabling variable frequency operation of the AC load.

Abstract: Exemplary embodiments are directed to a converter for an electrical system that is controlled in such that switching sequences for the converter, determined with respect to an optimization goal are modified such that by correcting a flux error resulting from assumptions on which the first optimization of the switching sequence is based.

Abstract: A voltage control operation unit receives, from a subtraction unit, a value obtained by subtracting a detection value of a voltage from a voltage command value, and performs a control operation for setting the voltage to be equal to the voltage command value. The voltage control operation unit outputs the calculated control amount as a current command value. A current control operation unit receives, from a subtraction unit, a value obtained by subtracting a detection value of a current from a current command value, and performs a control operation for setting the current to be equal to the current command value. A driving signal generation unit generates a signal for driving a boost converter based on a duty command value received from the current control operation unit.

Abstract: To prevent demagnetization of a permanent magnet synchronous rotating machine, a rotating machine control device according to the present invention is a rotating machine control device comprising: a power converter having a switch part on each of a positive side and a negative side for each phase; and short circuit detection unit for detecting a short circuit of the switch part, wherein a command to turn on positive-side switches and negative-side switches of a plurality of phases of the switch part is issued in the case where the short circuit detection unit detects the short circuit.

Abstract: A control apparatus is for use in a power conversion system including a DC/AC converter circuit connected to an electric rotating machine at output terminals thereof and to a DC power source at input terminals thereof through a switching means, a capacitor being connected across the input terminals of the DC/AC converter circuit. The control apparatus includes a current supply means configured to perform current supply control to supply a current to the electric rotating machine in order to discharge the capacitor by manipulating the DC/AC converter circuit in a state where the switching means is set open, and a speed lowering means configured to apply a brake force to a rotating shaft of the electric rotating machine to reduce a rotational speed of the electric rotating machine prior to the current supply control being performed by the current supply means if the rotational speed exceeds a specified speed.

Abstract: An actuator system having an actuator with an auxiliary switch. Make and break connection positions of the auxiliary switch relative to a rotative position of an output shaft coupling may be adjusted electronically according to an adjustment signal. The adjustment signal may be conveyed to the actuator from a computer or controller via a two-wire polarity insensitive bus. The adjustment signal may instead be provided an auxiliary potentiometer.

Abstract: Provided is an integrated-inverter electric compressor with suppressed self-noise interference in an inverter unit, simplified electrical connections between an inverter circuit and a filter circuit, and fewer welded positions. A housing (2) has, on the periphery thereof, an inverter box (5) accommodating the inverter circuit (21) and a junction box (6) communicating with the inverter box (5) and accommodating a plurality of high-voltage components constituting a noise-suppression filter circuit (27). The plurality of high-voltage components accommodated in the junction box (6) are electrically connected via a busbar (33). The busbar (33) includes branched busbars (34) branched off near connections with a high-voltage component installed close to the inverter circuit (21), and the branched busbars (34) are connected to P-N terminals (25) of the inverter circuit (21) in a communicating section (12) between the junction box (6) and the inverter box (5).

Abstract: There are provided a driving circuit, a driving module, a motor driving apparatus capable of adjusting a driving current driving a power semiconductor device, the driving circuit including a driving unit including a plurality of drivers and selecting a corresponding driver among the plurality of drivers according to a selection signal to determine a current level of a driving signal for driving a semiconductor device, a timing controlling unit detecting a phase shift time of the driving signal transferred to the semiconductor device and comparing the detected time with a preset reference time to control the phase shift time of the driving signal, and a driving controlling unit providing the selection signal for selecting a driver to be driven among the plurality of drivers of the driving unit according a control signal from the outside and a timing control signal of the timing controlling unit.

Abstract: A drive and control circuit for motor system and the method thereof are disclosed. The motor system could be applied in a cooling device, wherein the motor system comprises a rotor, a coil and a bridge circuit. The drive and control circuit comprises a control unit, a state detecting circuit, a load determining circuit, and a startup setting circuit. The startup setting circuit makes the motor run with the maximum torque, thus to make the motor system start up easily and quickly. The load determining circuit detects the load of the motor system, thus to generate a load determining signal to determine the speed of the motor system. The control unit could be realized with few components so as to save the costs.

Abstract: A device and method to determine the stopping rotor position of a washing machine motor includes an inverter, a permanent magnet synchronous motor, and an electronic motor controller. The controller determines the stopped rotor position of the motor by measuring induced currents in the stator field coils of the motor. While the motor is de-energized and slowly rotating, the controller directs the inverter to connect all of the stator field coils of the motor together. The stator field coils may be connected to a common D.C. rail, output from an A.C.-D.C. converter of the washing machine. In an embodiment, the controller determines the rotor position based on the polarities of current induced in the stator field coils. In another embodiment, the controller determines the rotor position based on the phase angle and angular frequency of the three phase currents, transformed into a stationary reference frame.

Abstract: A control circuit for a blender provides low-cost power conditioning through the use of a high resistance which provides temporary power for operation of low-voltage logic circuitry and low-voltage switches for a time sufficient to switch the motor on, and a lower resistance which provides sufficient power for maintaining the motor on state indefinitely as instructed by the low-voltage logic circuitry. Low average power dissipation is provided by powering the low-voltage logic circuitry and low-voltage switches using the high resistance in a standby mode and switching in the lower resistance only when the motor is activated.

Abstract: A motor for a synchronous electric machine includes a first inverter configured to provide alternating current power at a first plurality of phases. Also included is a second inverter configured to provide alternating current power at a second plurality of phases. Further included is a first stator winding and a second stator winding each in operable communication with the first inverter and the second inverter and configured to operate synchronously at a first phase, a second phase and a third phase. Yet further included is a first interphase transformer for receiving one of the first plurality of phases and one of the second plurality of phases for communicating a pair of simultaneous, matching voltage outputs to the first stator winding and the second stator winding for reducing a stress imposed on a rotor.

Abstract: A motor drive device includes an inverter circuit, a driver circuit for outputting a PWM signal to the inverter circuit, a booster circuit for boosting a power supply voltage supplied from a power supply circuit, a fail safe circuit arranged between the inverter circuit and the motor, and a fail safe drive unit for outputting a signal for turning ON/OFF a semiconductor switching element of the fail safe circuit. A boost voltage output from the booster circuit is supplied to the driver circuit and also supplied to the fail safe drive unit. The fail safe drive unit drives the semiconductor switching element of the fail safe circuit by such boost voltage.