Abstract: A current control method and a motor control circuit are provided. The motor control circuit includes a first rectification circuit and a second rectification circuit connected in parallel between a live wire and a natural wire of a power supply, a sampling resistor, and a controller connected to the second rectification circuit. The first rectification circuit is connected to the motor. The current control method include obtaining a periodic waveform signal of a bus voltage; collecting a bus current value through the sampling resistor; sampling the periodic waveform signal for a plurality of times; linearly fitting multiple voltage values obtained at a plurality of sampling time points to obtain multiple slopes; obtaining a power frequency according to the multiple slopes; calculating a compensation current value according to the power frequency; and generating a control signal according to the compensation current value and the bus current value.

Abstract: Methods, apparatus, systems, and computer program products for estimating error in an electric motor position sensor are disclosed. In a particular embodiment, an electronic control unit (ECU) for an electric motor receives, during a first state of operation of the electric motor, a first plurality of time samples of a first output signal from a position sensor, the first output signal indicative of a rotational position of the electric motor during the first state. The embodiment includes determining a first magnitude value for each of the first plurality of time samples of the first output signal, determining a first magnitude ripple value based upon the plurality of first magnitude values, and determining a first absolute angle error based on the first magnitude ripple value. The embodiment further includes determining an estimated error offset based on the first absolute angle error and storing the estimated error offset in a memory.

Abstract: A control circuit for an electric motor includes low and high voltage subcircuits, and an isolation barrier therebetween. The low voltage subcircuit comprises a current controller configured to generate a driving signal, and a feedback loop. The high voltage subcircuit comprises a power bridge configured to output a current that drives the motor, a current sensor configured to measure the current, an analog front-end and an analog-to-digital converter (ADC). The analog front-end is configured to apply as a function of the measured current. The isolation barrier comprises an isolator having: first and second channels to pass respectively a clock signal and a control signal from the low to high voltage subcircuit to select the gain; and third and fourth channels to pass respectively an output signal of the ADC and a replica of the clock signal from the high to low voltage subcircuit.

Abstract: An object of the present invention is to sufficiently suppress a vibration and noise generated in a motor. A motor control device includes a first inverter circuit and a second inverter circuit of a redundant system, the first inverter circuit and the second inverter circuit controlling a motor, and a control unit that controls the first inverter circuit and the second inverter circuit. The first inverter circuit converts the DC power into the AC power based on a PWM signal generated by using a first carrier signal. The second inverter circuit converts the DC power into the AC power based on a PWM signal generated by using a second carrier signal. The control unit shifts phases of the first carrier signal and the second carrier signal by using, as a reference, pulsation of an electromagnetic force caused by a magnetic circuit of the motor.

Abstract: A motor driving apparatus includes a first motor including first windings respectively corresponding to phases, a second motor including second windings respectively corresponding phases, a first inverter including first switching elements and connected to a first end of each of the first windings, a second inverter including second switching elements, a first changeover switch including third switching elements respectively connected to a second end of each of the first windings at one end and connected to each other at the other end, a second changeover switch including switches selectively connecting the second inverter with the second end of each of the first windings or the second inverter with a first end of each of the second windings, and a controller configured for controlling the states of the first switching elements, the second switching elements, the third switching elements and the switches based on preset conditions.

Abstract: According to one embodiment, a motor drive apparatus includes a first inverter, a second inverter, and a controller. This controller rotationally moves, at the time of startup of a motor, a rotor of the motor to an initial position by DC excitation of supplying DC exciting currents from the first and second inverters to the phase windings of the motor and, after this rotational movement, PWM-controls switching of the first and second inverters in such a manner that a rotational speed of the rotor becomes a target rotational speed. Then, the controller carries out the DC excitation fey which a zero-axis current in each of the phase windings becomes approximately zero.

Abstract: A switching method for six-step motor drive with an output inverter that provides commutation switching of power to the phase windings of a driven motor includes regulating the current to the output inverter and to the motor by a variable bus. switching six transistors of a three phase H-bridge and six associated freewheeling diodes of the output inverter by a pair of two transistors to commutate power to the phase windings conducting during conduction steps, and at each commutation step one off-going transistor is switched off and one on-going transistor is switched on the switching method further comprising monitoring of the back emf on two legs of the phase windings of the motor for determining commutation timing, and commutating the output inverter through non-simultaneous switching of the off-going transistor with switching of the on-going transistor.

Abstract: A power converter to supply power to each phase of a three-phase motor includes a booster circuit connected to a DC power supply to boost an input voltage input from the DC power supply in response to a pulse width modulation boosting signal, an inverter connected to the booster circuit and including a three-phase switching circuit including switches, and an output connected to the three-phase switching circuit to supply power to each phase of the three-phase motor, and a controller to output the pulse width modulation boosting signal to the booster circuit and output the pulse width modulation boosting signal to the booster circuit when detecting that the booster circuit is in a boosted state.

Abstract: Disclosed are a modulation strategy suitable for balancing losses of power switches in a bridge arm of a neutral point clamped three level inverter and an implementation method. The modulation strategy includes that an operation type of an inverter is determined and a corresponding modulation style is selected on the basis of a power factor (PF) angle; a corresponding modulation interval is selected according to the modulation style; and drive signals for various power switches are outputted, to balance switching losses of inner and outer sides of a bridge arm. The modulation strategy of the present disclosure enables the rational utilization of freewheeling paths to achieve a balanced distribution of losses between the inner and outer power switches of the inverter bridge within the entire PF range, thereby prolonging the service life of power electronic devices.

Abstract: An electrified vehicle having a first inverter having a DC terminal and a plurality of legs respectively connected to one end of each of a plurality of coils of a motor, a second inverter connected to the DC terminal, and including a plurality of legs connected to the other ends of the plurality of coils, respectively, a plurality of transfer switches respectively having one end connected to a neutral terminal for the plurality of coils and the other end connected to the other end of each coil, an overvoltage protection circuit including a clamping switch, a resistor, and a capacitor, and connected to the neutral terminal and the DC terminal, and a controller controlling a turned-on state of the plurality of transfer switches according to the motor driving mode. When the motor is driven, the controller controls a turned-on state of the clamping switch.

Abstract: A control device (8) for an inverter (2) that feeds an electric machine (3), wherein the control device (8) is configured to provide pulse-width modulated switching signals (15) for driving switching elements (12) of the inverter (2), wherein the control device (8) is configured to determine a modulation type by means of which the pulse-width modulated switching signals (15) are generated depending on operating point information that describes an operating point defined by at least one operating parameter, and to use a first modulation type in at least one first operating region (21, 28, 30, 31) and a second modulation type in another operating region (32, 32a, 32b).

Abstract: A motor drive device is proposed. The motor drive device is configured to drive a motor having a plurality of windings respectively corresponding to a plurality of phases, and includes: a first inverter including a plurality of first switching elements, and connected to a first end of each of the plurality of windings; a second inverter including a plurality of second switching elements, and connected to a second end of each of the plurality of windings; and a controller configured to generate phase voltage commands of the first inverter and phase voltage commands of the second inverter based on preset voltage commands of the motor so that the phase voltage commands of the first inverter and the phase voltage commands of the second inverter are respectively represented as vectors of different angles.

Abstract: A controller includes first and second setting sections. The first setting section sets a first duty-cycle, which is a percentage of a switch-on time period of a drive switch in one switching-cycle, by peak current-mode control to control a reactor current to be a current-command value generated based on an AC-voltage value. The second setting section sets a second duty-cycle, which is the percentage of the switch-on time period of the drive switch in one switching-cycle, by average-current-mode control to control an average value of the reactor current to be the current-command value. The controller operates the drive switch at the first duty-cycle when an absolute value of the AC-voltage value is equal to or more than a threshold less than an amplitude of the AC-voltage value, and operates the drive switch at the second duty-cycle when the absolute value of the AC-voltage value is less than the threshold.

Abstract: A method for operating a drive device for a motor vehicle is provided, wherein the drive device has an electric machine which is electrically connected to a DC power source via an inverter controlled by means of pulse width modulation. The pulse width modulation is performed depending on a predetermined duty cycle. When the duty cycle that is less than a threshold value, a continuous pulse width modulation is used to control the inverter. The pulse width modulation is switched to a discontinuous pulse width modulation when the threshold value is exceeded. A motor vehicle and a drive device for a motor vehicle are also provided.

Abstract: An object of the present invention is to provide a power conversion device capable of suppressing an increase in a current flowing through a motor even if a voltage command exceeds the amplitude of a carrier wave. In order to achieve the above object, the power conversion device controls the driving of a motor by converting a DC voltage into a voltage based on a voltage command by an operation of a switching circuit and includes: a modulated wave generator that generates a first modulated wave from the voltage command; and a control signal generator that generates a control signal for controlling the operation of the switching circuit from the first modulated wave and a carrier wave. The modulated wave generator generates a square wave based on a voltage command norm as the first modulated wave.

Abstract: An electric tool includes a motor and a motor control device. The motor control device is configured to update a command value of a speed of the motor based on a parameter relating to at least one of a voltage of a direct-current power supply for the motor or a magnitude of a load applied to the motor during rotation of the motor.

Abstract: An automatic control system for a phase angle of a motor is provided. A current detector circuit detects a current signal of the motor to output a current detected signal. A control circuit outputs a control signal according to the current detected signal indicating a time point at which the current signal reaches a zero value. A driver circuit outputs a driving signal according to the control signal. An output circuit operates to output a motor rotation adjusting signal to the motor to adjust a rotational state of the motor according to the driving signal.

Abstract: A power converter includes a converter circuit, an inverter circuit, a clamp circuit, a scrubber circuit, and an element including a resistive component. The converter circuit generates from an AC voltage source a DC voltage with AC components superimposed. The inverter circuit has an input connected with an output of the converter circuit. The inverter circuit is configured to convert the DC voltage into an AC voltage by switching, and output the AC voltage to an inductive load. The clamp circuit includes a first capacitor and a first diode connected in series. The clamp circuit is connected between a positive output and a negative output of the converter circuit. The snubber circuit includes a second capacitor and a second diode connected in series. The snubber circuit is connected between the positive output and the negative output of the converter circuit.

Abstract: An inverter controller is used to control an inverter circuit, which drives a vehicle on-board electric motor using a vehicle on-board electricity storage device. A rotation controlling unit of the inverter controller executes a process that derives two-phase voltage command values based on an external command value delivered from an external device and an actual rotation speed, and a process that derives three-phase voltage command values based on the two-phase voltage command values. In a case in which a voltage utilization factor is less than or equal to a utilization factor threshold, the rotation controlling unit derives, by switching at a switching period, sets of three-phase voltage command values of which the line voltages of the vehicle on-board electric motor are the same and the variation ranges are different.

Abstract: Systems and methods disclosed herein allow efficient reallocation of PoE when a PSU for a PSE fails. A PSE initially receives power from at least two PSUs and provides PoE to at least two PDs. When power from one of the PSUs becomes unavailable, the PSE refrains from providing PoE to a first PD, but continues providing PoE to a second PD. The PSE sends a communication to the second PD requesting that the second PD allow the PSE to allocate less power to the second. If the second PD confirms that allocating less power to the second PD is acceptable, the PSE reduces the amount of power allocated to the second PD and allocates at least some of the power saved by the reduction to the first PD.

Abstract: A drive system and method for controlling a synchronous motor having several phases, in which a method for controlling a drive system includes a synchronous motor having several phases comprises the steps: providing appropriate operating parameters for the synchronous motor by processing an input of the drive system; in case of a determination of a fault of one of the phases, calculating a zero sequence voltage for a neutral conductor based on motor parameters estimated by a parameter estimation algorithm based on detected operating parameters; and applying the calculated zero sequence voltage to the neutral conductor.

Abstract: A variable speed drive includes an output terminal for delivering a drive voltage; a power inverter for generating the drive voltage; a drive controller for controlling the generation of the drive voltage; and a current sensor for providing a drive current intensity signal to the drive controller. The drive controller includes a PWM generator; a control law module; and a state variable estimator estimating a state variable of the controlled AC electric motor.

Abstract: Described herein is a method of cooling a plurality of power devices, where the power devices are arranged as a plurality of switches used to generate a three-phase output AC voltage. Based on power device stress data, one or more switches (associated with one or more phase output AC voltages) may be identified as requiring more cooling than other of the switches. The switches are controlled to apply a common mode component voltage to each of the three phases for at least a portion of one or more output AC voltage segments. The common mode component voltage has a maximum amplitude that is sufficient to clamp the phase AC output voltage of the identified phase(s) to the positive supply rail voltage and/or negative rail supply voltage when the respective phase AC voltage is approaching respectively the positive supply rail voltage or negative supply rail voltage to cool the identified switch(es).

Abstract: A motor control apparatus includes an excitation unit and a control unit. The excitation unit includes switching elements connected to a power supply and to different motor coils. The excitation unit excites an excitation phase targeted for excitation among motor excitation phases by the control unit driving the switching elements. When the excitation phases are excited, the control unit drives, in a first time period and based on a first PWM signal, a first switching element connected to a first phase coil corresponding to a first phase of the excitation phase targeted for excitation and, in a second time period and based on a second PWM signal, drives a second switching element connected to a second phase coil corresponding to a second phase of the excitation phase. The control unit controls outputting a duty ratio of the second PWM signal to the second switching element in the second time period.

Abstract: A heating, ventilation, and air conditioning (HVAC) system includes a compressor having a discharge port and a suction port, a first sensor configured to provide feedback corresponding to a first temperature of the working fluid exiting the compressor proximate the discharge port, a second sensor configured to provide feedback corresponding to a second temperature of the working fluid entering the compressor proximate the suction port, and an automation controller storing data indicative of an operational envelope. The operational envelope defines compressor operation coordinates corresponding to a range of suction temperatures and a range of discharge temperatures inside and outside of a target region of the operational envelope, and the automation controller is configured to control a target range of compressor speeds based on a comparison of the target region to an operation coordinate defined by the feedback from the first sensor and the feedback from the second sensor.

Abstract: A plural-fans driving apparatus is provided to drive a first fan and a second fan, and the first fan and the second fan are three-phase fans. The plural-fans driving apparatus includes a controller, a first three-phase motor driver structure, a second three-phase motor driver structure, and a protection and input interface circuit. The protection and input interface circuit is coupled to the first three-phase motor driver structure and the second three-phase motor driver structure, and protects the first three-phase motor driver structure and the second three-phase motor driver structure. The controller controls the first three-phase motor driver structure to drive the first fan, and controls the second three-phase motor driver structure to drive the second fan.

Abstract: A pulse width-modulated (PWM) driving method is provided for a PWM motor control system with zero-crossing compensation. The PWM driving method includes controlling each carrier generator of first, second and third PWM generators to generate a carrier offset between each of first, second and third carrier signals, at least when a current flowing in a respective phase of an alternating current (AC) motor of the PWM motor control system is between +/?10 mA, such that a voltage between respective nodes and a reference point of respective half-bridges of the PWM motor control system are offset to obtain a variable common mode voltage each time respective PWM signals are in an off-state, at least when the respective current is crossing zero.

Abstract: A control method for a space conditioning system operable with a stages thermostat, the method including: powering a control module comprising including an output terminal, a first input terminal, a second input terminal, and control logic; detecting receipt of the first input signal at the first input terminal; responsive to detecting receipt of the first input signal, outputting a first value of the plurality of values, the first value corresponding to the first input signal; after outputting the first value, outputting one or more values of the plurality of values, the one or more values being larger than the first value; detecting receipt of the second input signal at the second input terminal; and responsive to detecting receipt of the second input signal, outputting a second value of the plurality of values, the second value corresponding to the second input signal.

Abstract: A motor driving system includes first and second motors including multiple first windings and second windings; a first inverter including a DC terminal connected to a DC voltage source and an AC terminal connected to the multiple first windings; a first switch part including a plurality of first mode change switches connected to the multiple first windings; a second inverter including a DC terminal connected to the DC voltage source and an AC terminal connected to the plurality of first mode change switches; a second switch part including a plurality of second mode change switches connected to the AC terminal of the second inverter and the multiple second windings; a third switch part including a plurality of third mode change switches connected to the multiple first windings; and a controller configured to control the short-circuited state or the open state of the multiple first mode, second and third mode change switches, based on whether the first and the second motors are driven.

Abstract: A controller includes a first processor for a first power inverter. Computer-readable media is configured to store computer-executable instructions configured to cause the first processor to: generate a first clock signal and a second clock signal; identify a pulse width modulation method of the first power inverter and a pulse width modulation method of a second power inverter; identify and compare a switching frequency of the first power inverter and a switching frequency of the second power inverter; determine an optimized phase shift between the first power inverter and the second power inverter responsive to the pulse width modulation method of the first power inverter and the pulse width modulation method of the second power inverter and the switching frequency of the first power inverter and the switching frequency of the second power inverter; and synchronize the optimized phase shift between the first power inverter and the second power inverter.

Abstract: To improve steering feeling felt by a driver, a motor control device includes a processor and a memory which stores a program for controlling an operation of the processor. According to the program, the processor executes: switching from n-phase (n is an integer of three or more) energization control to n?1 phase energization control in response to a switching signal; acquiring a torque command value, an electrical angle of a motor, and an actual current value of the motor; generating a pre-current command value on the basis of the torque command value, the electrical angle of the motor, and the actual current value of the motor which are acquired; generating a current command value by applying dither control to the pre-current command value in a dead point range of an electrical angle range from 0 to 2?; and performing the n?1 phase energization control on the basis of the current command value.

Abstract: A method of controlling a power converter is provided. The power converter generates a three-phase output power by switching an input power through a plurality of switches. The method includes steps of: acquiring a three-phase output command corresponding to the three-phase output power; comparing the three-phase output command with a control carrier to acquire a voltage phase angle corresponding to the three-phase output command; acquiring a three-phase current value of the three-phase output power; detecting the voltage phase angle and a positive/negative change of the three-phase current value to decide a zero-sequence voltage; composing the zero-sequence voltage and the three-phase output command to acquire a three-phase output expected value; comparing the three-phase expected values with the control carrier to acquire a turned-on time of each switch; and switching the input power to adjust the three-phase output power according to the turned-on time of each switch.

Abstract: This motor control device includes a vector control unit. The vector control unit includes: a current control unit that calculates a before-compensation d-axis voltage command value and a before-compensation q-axis voltage command value; a first non-interference control unit that calculates a first d-axis non-interference compensation value on the basis of a q-axis current command value to compensate for the before-compensation d-axis voltage command value and calculates a first q-axis non-interference compensation value on the basis of a d-axis current command value to compensate for the before-compensation q-axis voltage command value; and a second non-interference control unit that cancels out an interference component of a d-axis current generated in a specific rotation range of a motor with a q-axis current and an interference component of the q-axis current generated in the specific rotation range with the d-axis current by using a variable integral gain varying depending on a motor rotation speed.

Abstract: A parameterless and position-sensorless MTPA control of a permanent magnet synchronous motor including: using three rotating reference frames having different observation angles to parse the current vector; using a target current value and a preset current-rotor angle y that is between the current vector and the qr-axis of the (dr, qr) rotor reference frame to obtain the angles between the current vector, the voltage vector, and the rotor position; obtaining the target voltage value and the target voltage angle by using the obtained angles to obtain the target phase voltage values for regulation. The method is simple in controlling the motor, improves the control efficiency and reliability, and improves the control accuracy.

Abstract: A control apparatus includes: a data acquisition part that is configured to acquire torque data indicating a drive torque of an electric motor, rotation number data indicating a rotation number of the electric motor, and DC voltage data indicating a DC voltage supplied to an inverter which supplies an AC current to the electric motor; a determination basis derivation part that is configured to derive a determination basis based on a drive efficiency of the electric motor by using the torque data, the rotation number data, and the DC voltage data; and a control method determination part that is configured to determine, based on the determination basis, which one of a one-pulse control and a pulse-width modulation control is employed as a control method of the inverter.

Abstract: The present disclosure provides a motor driving device capable of inhibiting unstable driving of a motor even in the occurrence of a sudden fluctuation of a power supply voltage. The motor driving device includes a power supply voltage sudden fluctuation detector, a power supply voltage fluctuation width generator and a current limit value setting unit. The power supply voltage sudden fluctuation detector detects a sudden fluctuation in a direction in which the power supply voltage rises. The power supply voltage fluctuation width generator detects a fluctuation width of the power supply voltage. When the sudden fluctuation is detected by the power supply voltage sudden fluctuation detection unit, a current limit value of the current limit value setting unit is reduced from a normal value and corrected by the correction width corresponding to the fluctuation width of the detected power supply voltage.

Abstract: A programmable serial input-output controller is provided. A timer circuit performs a timing operation. An input pin is configured to receive an input signal from an external circuit. An output pin is configured to provide an output signal to the external circuit. In an output mode, the sequence controller provides an initial level to the output pin and controls the timer circuit to perform the timing operation. In response to a duration of the timer circuit performing the timing operation reaching first transmission time, the sequence controller inverts the level of the output pin and controls the timer circuit to re-perform the timing operation. In response to the duration of the timer circuit re-performing the timing operation reaching second transmission time, the sequence controller inverts the level of the output pin.

Abstract: A method for determining rectifier-stage output current and/or grid-side currents (iu, iv, iw) of a frequency converter (1) having a passive rectifier (3), an inverter (4), a DC-link with a DC-link inductor (Ldc) and a DC-link capacitor (Cdc) between the rectification stage (3) and the inverter stage (4) is described. In a frequency converter the current information for the grid-side currents (iu, iv, iw) should be obtained without a current sensor at the grid-side (2). To this end the method comprises the step of calculating a current in the DC-link (5) by using at least a voltage value (Urec) and characteristics of the rectifier (3) in the DC-link (5) and/or grid side currents to form a corrected current using the calculated current and a measured current or currents or a fraction of a measured current or currents, or a fraction of a measured current or currents.

Abstract: A heating ventilation and air conditioning (HVAC) control system. The HVAC control system includes a sensor that detects a refrigerant released from an HVAC system and emits a signal indicative of the detection. The HVAC control system also includes a switch that blocks a flow of electricity to an enclosed space and a controller that receives the signal from the sensor and activates the switch to block the flow of electricity in response to detection of the refrigerant.

Abstract: A mode of a rectifier may be changed between at least fully passive and fully synchronous based upon direct current (DC) output by the rectifier and/or direct current voltage output by the rectifier. This extends the range of direct current output by the rectifier for a given range of DC voltage output by the rectifier.

Abstract: The present disclosure provides techniques for predicting failure of power switches and taking action based on the predictions. In an example, a method can include controlling the at least two parallel-connected power switches via a first driver and a second driver, the first a second driver responsive to a single command signal, measuring a failure characteristic of a first power switch, and disabling a first driver of the first power switch when the first failure characteristic exceeds a failure precursor threshold.

Abstract: A power converter is configured to measure an output current and to determine a multi-phase voltage reference as a function of the output current. Within the same switching period the voltage reference is determined, a modulation routine determines a modulation index for each phase of the output voltage. In some instances, one or more phases must start modulation during the switching period before the new modulation index is determined. The modulation routine stores the value of the modulation index generated from the prior switching period and uses the stored value when a new value is not yet ready. An offset value for the phase voltage which used a modulation index from the prior switching period is determined in order to compensate the phase voltages of the other phases and to maintain a desired line-to-line voltage output from the power converter.

Abstract: An electrified vehicle electrical system includes, among other things, a contactor enclosure, and contactor contacts housed within the contactor enclosure. A resistor is housed within the contactor enclosure or is housed within a relay enclosure outside the contactor enclosure.

Abstract: A motor control apparatus includes control circuitry and rotation direction adjusting circuitry. The control circuitry is configured to output, in accordance with a phase sequence with respect to a motor, a drive command signal which is generated based on a motor rotation signal output from a motor rotation detector to control the motor. The rotation direction adjusting circuitry is configured to match the phase sequence with rotation direction information included in the motor rotation signal if a first trouble signal showing excessive motor current or excessive motor speed is input via an operation unit.

Abstract: An object of the present invention is to effectively reduce vibration or noise caused by a motor. An inverter circuit 300 generates an alternating current from a direct current supplied from a direct current power supply 10 by using a plurality of IGBTs 311 which are switching elements, supplies the generated alternating current to a motor 100, and drives the motor 100. This alternating current includes a fundamental harmonic current corresponding to a rotational speed of the motor 100, and a harmonic current of a switching operation of the IGBTs 311. A controller 200 controls a second phase such that a first phase and the second phase are not superimposed on each other at a predetermined motor rotational speed, the first phase being a phase of an excitation force cyclically produced in the motor 100 by the fundamental harmonic current, and the second phase being a phase of an excitation force cyclically produced in the motor 100 by the harmonic current.

Abstract: A first converter performs power conversion and outputs AC power. The AC power outputted from the first converter is supplied to a first coil. The first coil is magnetically coupled with a second coil, and the AC power is transmitted from the first coil to the second coil. A second converter is connected to the second coil, and converts the AC power transmitted to the second coil to DC power and supplies the DC power to a load. A first control unit controls the first converter so as to alternately switch between a first state of outputting rectangular wave voltage which cyclically changes and a second state of outputting constant reference voltage, on the basis of required power of the load.

Abstract: A fault detection device has a pair of power supply lines connected to a high voltage battery via power supply relays. Capacitors and inverters for driving a motor are disposed between the power supply lines. A controller in the fault detection device controls the inverters to discharge the capacitors at different times after the power supply from the battery to motor is stopped by switching OFF the power relays. The controller then determines whether the capacitor voltage has dropped after each capacitor is discharged. Based on the determination result of the voltage drop in each of the capacitors, the controller can determine whether the power supply relays or the capacitors are malfunctioning.

Abstract: An inverter system includes a level skip prevention control section. The level skip prevention control section is configured to: in response to an upward shift of an output voltage level of a first one of phases, set a counter for inhibiting upward shifting of the output voltage level of the first phase during a predetermined duration, and set a counter for inhibiting downward shifting of an output voltage level of a second one of the phases other than the first phase during a predetermined duration; and in response to a downward shift of the output voltage level of the first phase, set a counter for inhibiting downward shifting of the output voltage level of the first phase during a predetermined duration, and set a counter for inhibiting upward shifting of the output voltage level of the second phase during a predetermined duration.

Abstract: An inverter performs a power conversion operation for converting DC power into AC power, includes an arithmetic control device provided with a voltage command signal generation unit, a synthesis processing unit, and a carrier wave comparison unit. The voltage command signal generation unit has a plurality of control systems, and outputs the first voltage command signal generated based on the first control system among the plurality of control systems, and the second voltage command signal generated based on the second control system different from the first control system among the plurality of control systems. The synthesis processing unit generates a synthesized voltage command signal obtained by synthesizing the first voltage command signal and the second voltage command signal at a predetermined ratio. The carrier wave comparison unit generates a PWM signal which is a gate drive signal for controlling the power conversion operation based on the synthesized voltage command signal.

Abstract: In some examples, an electric submersible pump includes a pump, an electric motor to drive the pump, and a controller. The controller can monitor at one or more terminals of the electric motor a value relating to total harmonic distortion. The controller can also determine whether to de-rate the electric motor in response to the monitoring at the one or more terminals of the electric motor of the value relating to the total harmonic distortion.