Abstract: In a system comprising a fuel and a rotating electrical machine, damage of a switching element is prevented when the rotating electrical machine becomes a locked state. In a power controller, it is monitored whether the rotating electrical machine is in the locked state or not. When the rotating electrical machines is judged to be in the locked state, a command for dropping output voltage is given to the fuel cell. Thus, inverter input voltage can be dropped, loss power of the switching element in the rotating electrical machine is dropped and damage can be suppressed. The rotating electrical machine is monitored to cancel the locked state or not while dropping of inverter input voltage is controlled. When the locked state is judged to be canceled, control of the fuel cell is returned to a state of regular operation control.

Abstract: A power conversion device includes a power switching circuit that has a plurality of series circuits in each of which a switching element that operates as an upper arm and a switching element that operates as a lower arm are connected in series, and a control circuit that generates control signals for controlling the continuity or discontinuity of the switching elements, and, if the relationship between the state of a switching element in a control cycle and the state of the switching element in the next control cycle is a discontinuous relationship, that additionally performs control to make the switching element continuous or discontinuous on the basis of the state of the switching element in the control cycle and the state of the switching element in the next control cycle.

Abstract: A voltage command generation unit generates a voltage command value, based on a current deviation relative to a current command value. A dq-axis voltage filter generates a voltage command value subjected to a filtering process for smoothing a change of the voltage command value in a time axis direction. Then, the voltage command value subjected to the filter processing is subjected to a voltage amplitude correcting process and a dq inverse transformation coordinate converting process, so that a phase voltage command for an AC motor is generated. Thus, it is possible to prevent both an amplitude and a phase of the voltage command for the AC motor from being changed rapidly even at a time of control mode switchover.

Abstract: The position of a rotor of a motor is determined. The motor includes a stator having a plurality of coils. The rotor includes at least one rotating magnetic field device. When the rotor is moving below a threshold speed, the current in the coils is measured. A pre-programmed data structure is accessed. The data structure stores stator currents associated with predetermined rotor positions. A first absolute position of the rotor is determined from the data structure according to the measured current from each of the coils. When the rotor is moving above the threshold speed, one or more rising or falling edges of magnetic field strength associated with the at least one rotating magnetic field device are sensed. At least one timing aspect of the rising and falling edges of magnetic field strength are compared to determine a second absolute position of the rotor.

Abstract: The invention discloses a current direction detection module including a conversion unit, a bridge unit and an operation unit. The conversion unit has primary and secondary sides, wherein the secondary side has first and second ends. The bridge unit has first, second, third and fourth rectifying elements and first, second, third and fourth nodes. Each rectifying element has an anode and a cathode. The anode of the first rectifying element is coupled to the fourth rectifying element. The anode of the second rectifying element is coupled to the first rectifying element. The anode of the third rectifying element is coupled to the second rectifying element. The anode of the fourth rectifying element is coupled to the third rectifying element. The first and second nodes are coupled to the first and second ends. The operation unit amplifies two bridge voltages at the third and fourth nodes and outputs an operation voltage.

Abstract: In response to the determination or estimation of a back EMF zero crossing event for the phase, a time T1 is calculated, T1 being representative of the desired absolute maximum value of the phase current. Current samples are taken by the current sampling unit symmetrically centered around T1. The values of the samples CS[1] to CS[10] are then input into the error function to calculate an error function value. The calculated error function value is input to the lead angle control unit which calculates a value for lead_angle. The value of lead_angle is calculated to be the adjustment in phase angle of the driving voltage profile that will minimize the absolute value of the error function. In generating and adjusting the driving voltage profile the driving voltage generation unit takes into account both lead_angle and the output of the position and speed estimation unit.

Abstract: A control circuit includes a current sensing circuit, an analog digital converter (ADC), an amplifying circuit, a processor, and a switching circuit. The current sensing circuit senses current supplied to an electronic device by a power supply and outputs a first voltage signal. The amplifying circuit amplifies the first voltage signal output from the current sensing circuit to a second voltage signal. The ADC converts the second voltage signal to a digital signal. The processor outputs pulse width modulation (PWM) signals according to the digital signal. The switching circuit receives the PWM signals to control a fan of the electronic device according to the PWM signals.

Abstract: A DC to three-phase AC inverter system includes a three-phase motor, an inverter circuit, switching elements, a capacitor, a DC power source and a control circuit. The DC power source is connected to the three-phase motor at a neutral point thereof. The control circuit calculates voltage commands, first through third divided boost commands by dividing a boost command, and first through third drive signals based on the voltage commands and the first through third divided boost commands. The second and third divided boost commands are used when the PWM control is performed by turning on and off the switching elements for the second and third phases while the switching elements for the first phase continues to be on or off state is set larger than those used when the PWM control is performed by turning on and off the switching elements for the first through third phases.

Abstract: An inverter circuit for a motor outputs three-phase AC currents, which are outputted from common connection points to stator coils, based on output voltage of a DC power source and a power supply capacitor by a switching operation of transistors. An inverter control circuit determines that a system main relay is turned off, upon receiving a main relay-off signal from an electronic control unit. The inverter control circuit turns on the low-side transistors, while turning off the high-side transistors. A discharge current flows from the positive electrode to the negative electrode of the power supply capacitor through the stator coil and the low-side transistors, so that electric charge stored in the power supply capacitor is discharged.

Abstract: A miniaturizable, low-cost highly reliable inverter unit. A control circuit section for controlling operating timing of high breakdown voltage semiconductor elements included in an inverter circuit section and first and second drive and abnormality detection circuit sections for outputting drive signals for driving the high breakdown voltage semiconductor elements according to the operating timing and for feeding back an abnormality of the inverter circuit section to the control circuit section are formed on an SOI substrate as one integrated circuit chip. On the integrated circuit chip, circuit formation areas which differ in reference potential are separated from one another by dielectrics. A plurality of level shifters for transmitting signals exchanged between circuit formation areas separated by the dielectrics are formed.

Abstract: A power conversion device includes a first inverter circuit and a second inverter circuit, a capacitor, and a microcomputer. The microcomputer switches a control operation, according to the steering state of a steering wheel, between a first state where a first duty center value is shifted to be lower than an output center value and a second duty center value is shifted to be higher than the output center value, and a second state where the first duty center value is shifted to be higher than the output center value and the second duty center value is shifted to be lower than the output center value. This can reduce a difference in heat loss between FETs while reducing the ripple current of the capacitor.

Abstract: In a torque motor driving device for wire cut electrical discharge machines, a voltage waveform rectified by a full-wave rectifying circuit, not using a high-capacitance electrolytic capacitor, is applied as an AC voltage to a single-phase torque motor by a bridge circuit including semiconductor switches. A PWM signal whose duty is adjusted so that the current flowing through the torque motor matches an instructed value is generated and the generated PWM signal is used for the operation of the bridge circuit.

Abstract: A drive with heat dissipation and energy-saving function for supplying power to drive a motor. The drive includes a driving circuit having a rectification section. The rectification section serves to receive AC current generated when the motor abruptly accelerates/decelerates and convert the AC current into DC current and output the DC current. The drive further includes a cooling module electrically connected to an output end of the rectification section. The cooling module is drivable by the DC current output from the rectification section to conduct out and dissipate heat.

Abstract: A system for controlling operation of a motor drive during fast start-up of an induction motor is disclosed. The system includes an AC motor drive having a PWM inverter and a control system to generate a command signal to cause the PWM inverter to control an output of the AC motor drive. The control system includes a start-up modulator that is selectively operable during start-up acceleration of the AC motor, the start-up modulator programmed to determine a motor current applied to the AC motor and a voltage of a DC bus, generate a first frequency offset that causes a frequency reference of the command signal to be decreased when the motor current is greater than a reference current threshold, and generate a second frequency offset that causes the frequency reference of the command signal to be increased when the DC bus voltage is greater than a reference voltage threshold.

Abstract: An autonomous controller allows an AC induction motor to operate over a broad range of AC power supply frequencies by reducing the amount of current supplied to the motor at lower frequencies. The controller detects the frequency of the power supply and switches the supply current on and off during each AC cycle to limit the RMS current to a value that is related to the detected frequency. Alternatively, the controller switches capacitive reactance into the power supply circuit which reduces the current supplied to the motor at lower AC frequencies.

Abstract: A battery power system, adapted for driving a motor system of a power unit with respect to at least one power mode signal and at least one motor control signal generated from the motor system, which comprises: a battery pack, an electrolytic capacitor, a boost converter, a first contactor, a first switch, an ultracapacitor, a first diode, a second contactor, a second switch, a current limiting element, a plurality of measuring elements, and an electrical energy controller; wherein the electrical energy controller is enabled to analyze the electrical power level of the ultracapacitor according the power mode signal, the motor control signal and the voltage/current signals generated from the plural measuring elements while using the result of the analysis to control the current directions and conductivity of the boost converter, the first contactor, the second contactor, the first switch and the second switch so as to achieve a variety of control modes accordingly.

Abstract: A driving apparatus drives a brushless motor that includes a plurality of windings. The apparatus comprises a plurality of switch half-bridges connected to a power line and to the windings, a memory adapted to contain a plurality of signal profiles to be cyclically applied to the plurality of windings of the motor, a multiplier for multiplying the profile values of the signals from the memory by a scale factor, a control circuit adapted to generate PWM signals for the switches of the plurality of switch half-bridges according to values output by the multiplier, a polarity detector configured to detect the polarity of the current passing trough at least one winding of the motor and a scale factor controller configured to modify the scale factor according to the detected current polarity and so as to make each signal profile to be applied to each winding of the motor either higher than the back-electromotive force or equal to the back-electromotive force generated by the motor.

Abstract: An electric power supply system has a power bus for providing DC power, and a control unit for a source of power to supply the power bus. The power unit includes a damping algorithm to provide damping to power supplied on the power bus. A motor and a motor control include a compensation block for tapping power from the bus, and identifying a portion of a supplied signal due to the damping. The compensation block provides a signal to a summing block that addresses the damping on the power bus prior to the power being supplied to the motor. A method of utilizing such a system is also disclosed.

Abstract: The present invention provides an inverter circuit for a vehicle, which includes: a switching unit that includes a plurality of switching elements and switches a direct current into an alternating current; and a variable clamping unit that clamps an overshoot in case the overshoot is generated, and stops the operation of the switching unit in case a system voltage is greater than a clamping breakdown voltage. The circuit enables a voltage (DC input voltage) greater than a breakdown voltage of clamping unit to be used as a system voltage.

Abstract: The present invention discloses a controllable rectification comprising an inverter (10), a control panel (20) and a drive panel (30). The inverter (10) may comprise three switch element groups connected in parallel. Each switch element group may comprise at least two switch elements connected in parallel. Each switch element may comprise an upper bridge-arm switch and a lower bridge-arm. The control panel (20) may generate a PWM waveform. The drive panel (30) may generate a drive voltage according to the PWM waveform to drive the upper bridge-arm switch and the lower bridge-arm switch of each switch element to conduct or break respectively, and to make the upper bridge-arms of the same switch element group to conduct or break simultaneously, and to make the lower bridge-arms of the same switch element group to conduct or break simultaneously. The present invention further discloses an electric motor comprising the same.

Abstract: When a short-circuit failure of any of switch portions (13) including switch elements (11) and parallel-connected feedback diodes (12) of an inverter circuit (7) is detected during the operation of a motor (1), a switch portion (13) where the short-circuit failure has occurred is checked for whether it is on the positive polarity side or the negative polarity side. The switch elements (11) are so controlled that all the switch portions (13) on the same polarity side as where the short-circuit has occurred are brought into a conducted state and all the others are disconnected. This prevents a large electric current from flowing into each switch portion of the inverter circuit without requiring any switch to block the power distribution between a motor and the inverter circuit when a short-circuit failure of the switch portion of the inverter circuit occurs.

Abstract: During motor acceleration control period that starts at time T1, if power supply output or supply current exceeds a predetermined level at time T2, PWM control in a PWM converter is turned off until a deceleration control period of T3 to T4 ends. As a result, DC link voltage (voltage of a power storage device) at the start of the deceleration control at time T3 drops to provide space for storing regenerative power; since the PWM control in the PWM converter is off during the deceleration control period, the regenerative power can be stored into the power storage device and reused in the next control cycle.

Abstract: A miniaturizable, low-cost highly reliable inverter unit. A control circuit section for controlling operating timing of high breakdown voltage semiconductor elements included in an inverter circuit section and first and second drive and abnormality detection circuit sections for outputting drive signals for driving the high breakdown voltage semiconductor elements according to the operating timing and for feeding back an abnormality of the inverter circuit section to the control circuit section are formed on an SOI substrate as one integrated circuit chip. On the integrated circuit chip, circuit formation areas which differ in reference potential are separated from one another by dielectrics. A plurality of level shifters for transmitting signals exchanged between circuit formation areas separated by the dielectrics are formed.

Abstract: A method is disclosed for estimating a rotation speed of an electric motor supplied by an inverter, by determining a time derivative of a stator current vector of the electric motor during a zero vector state of the inverter; and determining an estimate of the rotation speed of the electric motor on the basis of the determined time derivative of the stator current vector.

Abstract: A motor including a stator, a rotor, and a current supply unit. The stator includes a stator core, which has a plurality of teeth, and a plurality of coils, which are wound around the teeth. The rotor includes a plurality of magnets, which function as first magnetic poles, and salient poles, which function as second magnetic poles. Each of the salient poles is arranged between adjacent magnets spaced apart by a clearance from the magnets. When P represents the number of poles in the rotor and S represents the number of coils, a ratio P/S of the pole number P and the coil number S is represented by (4n?2)/3m (where n and m are integers that are greater than or equal to 2). The plurality of coils includes a plurality of coil groups including coils for three phases. The current supply unit executes a different current control for each coil groups.

Abstract: An inverter for driving a motor includes one or more power stages for producing one or more power signals for energizing the motor, each power stage including first and second III-nitride based bi-directional switching devices connected in series between a DC voltage bus and ground.

Abstract: A conveyor system includes an electric motor to move a conveyor. A voltage determining device is coupled to an alternating-electricity source that supplies alternating electricity to the conveyor system. A power supply appliance supplies power between the electric motor and the alternating-electricity source. The power supply appliance includes an inverter and an inverter control. The inverter includes a rectifying bridge and a motor bridge. The rectifying bridge input is coupled to the alternating-electricity source and the rectifying bridge output is coupled to the motor bridge input. The motor bridge output is coupled to the electric motor. The inverter control is coupled between the voltage determining device and the motor bridge. The inverter control is responsive to frequency and phase of the determined voltage of the alternating-electricity source to adjust the frequency and phase of the motor bridge output voltage such that the motor bridge output voltage is made to be essentially constant.

Abstract: A multiphase motor driving device has an inverter circuit. The inverter circuit includes a pair of upper and lower switching elements, a shunt resistor for phase current detection, and a voltage for driving a multiphase motor. The device includes a determination unit for shifting a detection timing of the current flowing to the shunt resistor from the OFF period to the ON period of the switching element on the upper side in the phase. The determination unit determines whether or not ON failure occurs based on the current flowing to the shunt resistor of the phase in the ON period. The device has a current value estimation unit for estimating a current value of the phase in a case where the detection timing is shifted based on currents flowing to the shunt resistors of other phases.

Abstract: A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

Abstract: A motor driving apparatus comprises: an AC/DC converter which converts AC voltage supplied from an AC power source into DC voltage through PWM switching control of a power switching device; and a DC/AC converter which converts the DC voltage into variable-frequency AC voltage for driving a motor in a controlled manner. The AC/DC converter includes: a control unit which generates, based on an error between the DC voltage and a DC voltage command value, a PWM signal for the PWM switching control of the power switching device; and a frequency/gain varying unit which sets the frequency of the PWM signal to be generated by the control unit and a control gain in the control unit higher than their normal levels during a period in which a load in the DC/AC converter varies.

Abstract: Certain exemplary embodiments can provide a system, machine, device, manufacture, circuit, and/or user interface adapted for, and/or a method and/or machine-readable medium comprising machine-implementable instructions for, activities that can comprise, via a predetermined information device, for a predetermined excavating machine comprising a plurality of Active Front Ends, each Active Front End electrically coupled to an AC power supply network of said predetermined excavating machine, each Active Front End adapted to provide DC power to a DC bus, said DC bus electrically coupled to a plurality of inverters, each inverter adapted to supply AC power to at least one operating motor, independently controlling a reactive power produced by each Active Front End.

Abstract: An apparatus for generating electromagnetic torque in an N-phase electric machine, N being a positive integer, includes N lines, each of the N lines including an input terminal, an output terminal, and a pair of thyristors, or of one thyristor and one diode pair. The N lines are connected between a mains and the electric machine. An apparatus is provided for repeatedly or continuously determining at least the sign of a voltage over the thyristor or diode-thyristor pair in at least one of the N lines, means are provided for repeatedly or continuously determining at least one parameter related to the electromagnetic field in the electric machine, and a control device is provided for controlling the operation of the thyristor or diode-thyristor pair of the at least one of the N lines.

Abstract: A method for shutting down an electric machine having a pulse-controlled inverter in the event of a malfunction. Undesirable side effects during shut-down of the electric machine may be minimized and the regular machine operation may be maximized when the electric machine is first switched to a disconnect mode in which all switches of the pulse-controlled inverter are open and subsequently is switched to a short-circuit mode in which the switches connected to the high potential are open and the switches connected to the low potential are closed.

Abstract: A device for improving efficiency of an induction motor that soft-starts the motor by applying a voltage to the motor that is substantially less than the rated voltage then gradually increasing the voltage while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the voltage to the motor is increased/decreased by measuring the phase angle between the voltage and the current to the motor and increasing the voltage when the phase angle is less than a minimum phase angle (determined during soft-start) and decreasing the voltage when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.

Abstract: A motor control system for heating, ventilation, and air conditioning (HVAC) applications is described. The motor control system includes a thermostat and an electronically commutated motor (ECM) coupled to the thermostat. The ECM is configured to retrofit an existing non-ECM electric motor included in an HVAC application and to operate in one of a plurality of HVAC modes. The HVAC modes include at least one of a heating mode, a cooling mode, and a continuous fan mode. The HVAC mode is determined based at least partially on outputs provided by the thermostat.

Abstract: A motor drive system includes: a three-phase motor; a power conversion device that supplies power for driving the three-phase motor; and an output filter that is arranged between an output of the power conversion device and the three-phase motor and has a configuration in which a setting value of a filter resonance frequency is selectable and changeable.

Abstract: A phase current prediction method is disclosed. The phase current prediction method predicts current representative of a PWM period using a motor model which receives current measured through a single current sensor as an input, instead of the measured current, and determines the predicted current to be phase current.

Abstract: A chiller system is provided with a compressor, a condenser, and an evaporator connected in a closed refrigerant loop. A motor is connected to the compressor to power the compressor. A variable speed drive is connected to the motor. The variable speed drive is arranged to receive an input AC power at a fixed input AC voltage and a fixed input frequency and provide an output power at a variable voltage and variable frequency to the motor. The variable voltage has a maximum voltage greater in magnitude than the fixed input AC voltage and the variable frequency has a maximum frequency greater than the fixed input frequency. The variable speed drive includes a converter connected to an AC power source providing the input AC voltage, the converter is arranged to convert the input AC voltage to a DC voltage. A DC link is connected to the converter. The DC link is arranged to filter and store the DC voltage from the converter. An inverter is connected to the DC link.

Abstract: A torque limit section that applies limit to a torque instruction value of an electric motor such that a switching elements temperature is restricted to no more than an element upper limiting temperature includes a torque restriction section that finds a torque restriction value for restricting the torque of the electric motor in accordance with the said switching elements temperature; a torque restriction mitigation section that finds a torque restriction mitigation value for mitigating the torque limit value in accordance with the integrated value of the deviation of the element upper limiting temperature and the switching elements temperature; a first subtractor that finds a torque restriction value by subtracting the torque restriction mitigation value from the torque limit value; and a second subtractor that finds a limited torque instruction value obtained by subtracting the torque limit value from the torque instruction value and outputs this to the gate generating section.

Abstract: Generation voltage control or generation torque control is performed as suitable control based on an external command or a load of a generator motor, to thereby prevent a rapid change of a generation torque or excessive power generation. A power converter control apparatus includes: a power conversion unit including a bridge circuit for controlling energization of an armature winding and a field circuit for controlling energization of a field winding; and a control device including B-terminal voltage detection means, field current detection means, generation voltage control means, generation torque control means, and control selection means. The control selection means selects the one of the generation voltage control means and the generation torque control means based on one of a command from an outside and a load of the generator motor.

Abstract: Systems and methods are provided for monitoring current in an electric motor. An electrical system comprises a direct current (DC) interface, an electric motor, and an inverter module between the DC interface and the electric motor. A first current sensor is configured to measure a DC current flowing between the DC interface and the inverter module. A second current sensor is configured to measure a first phase current flowing through the first phase of the electric motor. A control module is coupled to the current sensors, and the control module is configured to determine an expected value for the first phase current based at least in part on the DC current measured by the first current sensor and take remedial action based on a difference between the expected value and the measured first phase current.

Abstract: An apparatus operable in a wet environment includes a voltage doubler circuit including a pair of diodes, a pair of direct current switching elements connected between the respective diodes and a common point, a controller, an interface connected to the controller for receiving external status signals, and a switching arrangement responsive to signals from the controller to select the full power mode or a controlled power mode. In the controlled power mode, the switching elements are switched in a predetermined sequence such that only one of the switching elements conducts current during any one half cycle of the AC output voltage applied to the motor.

Abstract: An electric motor control circuit includes an electric energy storage device electrically connected via DC power buses to an inverter circuit that connects via an alternating current circuit to an electric machine. A capacitive shunt circuit connects between the power buses. Current flow through the capacitive shunt circuit to the chassis ground is monitored. A fault is identified when the current flow through the capacitive shunt circuit to the chassis ground exceeds a threshold.

Abstract: The present invention relates to a method and a system for controlling a permanent magnet excited, brushless, electronically commutated, three-phase electric motor (2) wherein a single-phase main AC voltage (UN) having a mains frequency (fN) is rectified and supplied to an inverter (8) via a slender intermediate circuit (6) containing no, or minimum, intermediate circuit reactance as intermediate circuit voltage (Uz) pulsating at double the mains frequency (2fN) which is actuated for powering and commutating the electric motor (2). Control takes place by means of a field-oriented current-space vector regulator, wherein a q-current (iq) as torque-forming component of the current-space vector (i) is regulated perpendicularly to the permanent magnetic field and a d-current (id) can be regulated as a field-influencing component of the current-space vector (i) in the direction of the permanent magnet field.

Abstract: A control device that includes an AC voltage command determination section that determines an AC voltage command value, which is a command value of the AC voltage supplied from the DC/AC conversion section to the AC electric motor, on the basis of a target torque of the AC electric motor and a rotational speed of the AC electric motor; and a system voltage command determination section that determines a system voltage command value, which is a command value of the system voltage generated by the voltage conversion section, on the basis of the AC voltage command value and the system voltage.

Abstract: A method and an apparatus for the failsafe monitoring of an electromotive drive without additional sensors, including a drive having a three-phase control of an electric motor, detection of the current and voltage profiles of each of the three phases, as they are forwarded to the motor by drive electronics, determination of the load speed while using the detected current and voltage values, where the determination of the load speed takes place by calculating an observer model with reference to the detected current, to the detected voltage, to the frequency preset by the control and to the characteristic data of the motor and generation of a failsafe switch signal for the motor when the calculated load speed does not correspond to a preset desired speed within the framework of preset tolerances. The load torque can also be determined and monitored with reference to the observer model.

Abstract: An electric compressor control device includes: an inverter for electric compressor motor; a communication microcontroller arranged in a low-voltage region for transmission of an instruction signal via a high-speed communication bus; and a control microcontroller arranged in a high-voltage region and connected to the communication microcontroller via an insulation element for transmitting the instruction signal from the communication microcomputer as an inverter control signal to the inverter. The power voltage of the communication microcomputer is supplied from a low-voltage power source. The voltage from the low-voltage power source is transformed via a transformer and supplied as a power voltage of the control microcontroller.

Abstract: A pre-charge circuit limits in-rush currents on a direct current (DC) link that includes a first DC link bus and a second DC link bus. The pre-charge circuit includes a switching device connected in series with the first DC link bus. The switching device has an ON state in which power flow is enabled on the DC link and an OFF state in which power is disabled on the DC link. A controller selectively modulates the state of the switching device to limit in-rush currents on the DC link.

Abstract: An HVAC/R system is configured with a variable frequency drive power supply which provides power to both a three-phase motor and to a single-phase motor. In some embodiments, the three-phase motor is a compressor motor and the single-phase motor is a condenser fan motor.

Abstract: A machine tool a tool includes a supporting member relatively movable to a workpiece along a predetermined axis, a servo motor configured to drive the tool supporting member to the workpiece along the predetermined axis, a sizing sensor configured to measure a profile of the workpiece and to output a size deviation of measured values from a target profile, and a position detector configured to detect at least one of a relative position of the tool supporting member to the workpiece and a rotational position angle of the servo motor. The a servo driver is configured to drive the servo motor, and has a first feedback control having an output based on the size deviation, and a second feedback control based on an output of the position detector. The servo drives the servo motor by combining the outputs of the first and second feedback controls.