Abstract: Relays are inserted and connected between a battery and a boosting converter, and other relays are inserted and connected between another battery and another boosting converter. A controller outputs control signals that control opening/closing of the relays. When short-circuit of a switching element occurs in the boosting converters, the controller controls turning-off of the relays such that at least one of order and timing of turning off the relays is changed depending on which of the switching elements is short-circuited.

Abstract: Provided is a variable frequency drive and a rotation speed searching apparatus for an induction motor incorporated therein. The rotation speed searching apparatus is featured by scanning the rotor frequency of the induction motor and determining either the error between a detected DC-bus voltage and a set DC-bus voltage or the error between a detected output current and a set output current, so that the rotation speed of the induction motor can be searched out.

Abstract: An inverter includes a voltage command generator generating a voltage command value according to an externally specified voltage value, a PWM signal generator generating a PWM signal according to the voltage command value and frequency command value, and a switching unit generating a three-phase AC power according to the PWM signal. The voltage command generator decreases the voltage command value if the output current increases, to prevent the rotation speed of a prime move from suddenly changing. If the output current exceeds a preset upper current threshold, the voltage command value is clamped at a preset minimum output voltage, thereby securing the minimum output voltage for an increase in the output current.

Abstract: A multiphase electromagnetic machine may be controlled by controlling currents in one or more phases of the multiphase electromagnetic machine. A control system may be used to determine how much current to deliver to, or extract from, each phase. The control system may use an objective function, subject to one or more constraints, to determine the current. The control system may use position information to determine the objective function, constraints, or both.

Abstract: A control system for an AC motor determines a slope Ktl of a tangent TL at an operating point Pa corresponding to the current motor operating state and voltage phase (?0) on a torque characteristic curve that is plotted according to a torque equation representing an output torque characteristic with respect to the motor operating state and the voltage phase of the rectangular wave voltage. The control system further calculates a voltage phase change amount ?ff for use in feed-forward control, according to ?Ttl/Ktl obtained by dividing a torque compensation amount ?Ttl for feed-forward control by the slope Ktl.

Abstract: It is presented a control device for driving an electric motor, wherein a drive control signal for the electric motor is arranged to be determined using a calculated rotor flux. A direct quadrature, dq, coordinate system relating to a rotor of the electric motor is used. The control device comprises a flux estimator arranged to determine the calculated rotor flux using a quadrature axis voltage, a measured direct axis current, a measured quadrature axis current, an angular velocity, stator resistance and a direct axis inductance and an actual torque calculator arranged to obtain an actual torque estimation using the calculated rotor flux, the measured direct axis current and the measured quadrature axis current. A corresponding method is also presented.

Abstract: In order to cause the residual magnetic flux in an induction motor to decay in a short time without an excessive current flow, an induction motor control apparatus continues an operation in which an inverter apparatus is caused to output a zero voltage to the induction motor for a predetermined time before deactivating an operation of the inverter apparatus.

Abstract: A steering control apparatus includes a direct current power source, a three-phase alternating current motor, and a motor driving circuit. An emergency switching element is provided on at least two phases of a three-phase power supply line connected to the three-phase alternating current motor within the motor driving circuit, and the emergency switching element is turned off when an abnormality occurs such that the motor driving circuit is disconnected from the three-phase alternating current motor. The emergency switching element is a MOSFET, and the MOSFETs are provided in pairs in each of the two phases of the three-phase power supply line. Further, parasitic diodes of the pairs of MOSFETs are disposed in opposite orientations to each other.

Abstract: A motor driving control apparatus includes a motor driving unit which drives a motor and a driving control unit which supplies to the motor driving unit a command value for the motor driving unit to drive the motor. A power characteristic acquiring unit acquires a power characteristic of an AC power supply that supplies power to the motor. A control parameter determining unit determines based on a voltage characteristic of the AC power supply whether, during driving of the motor, the voltage of the AC power supply drops to a level that adversely affects the driving of the motor, and if positive, the control parameter determining unit sets a control parameter so that the voltage of the AC power supply does not drop below that level and supplies the control parameter to the driving control unit in order for the driving control unit to determine the command value.

Abstract: A power conversion device in which an inverter for controlling a load is connected to an alternating current power system, and arranged to perform an electric power assist by connecting a direct-current power assist device having a chopper and a charge device to a direct-current circuit of the inverter. The device including a setting section to set charge and discharge target values in accordance with a sensed value of the direct-current voltage of the inverter; a charge control section to perform a charge control based on the charge target value; a discharge control section to perform a discharge control based on the discharge target value; and an instantaneous-low high-speed-compensation section to estimate an electric power corresponding to a direct-current sensed voltage of the inverter, and to output a value to the discharge control section which is obtained by dividing the estimated value by the direct-current sensed voltage.

Abstract: Embodiments of the present invention relate to methods, systems and apparatus for controlling operation of a multi-phase machine in a vector controlled motor drive system when the multi-phase machine operates in an overmodulation region. The disclosed embodiments provide a mechanism for adjusting a duty cycle of PWM waveforms so that the correct phase voltage command signals are applied at the angle transitions. This can reduce variations/errors in the phase voltage command signals applied to the multi-phase machine so that phase current may be properly regulated thus reducing current/torque oscillation, which can in turn improve machine efficiency and performance, as well as utilization of the DC voltage source.

Abstract: Systems, methods and computer program products for reducing or removing current spikes generated during a current recirculation period associated with phase switching in a spindle motor are described. In some implementations, the duty cycle of the drive signals applied to the windings of the spindle motor can be adjusted to reduce or eliminate the current surge resulting from current recirculation. In some implementations, the duty cycle of the drive signals during spin-up can be reduced based on a current limit, and the reduced duty cycle can then be used to drive the spindle motor taking into account of current surges in the supply current.

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: An electric motor is driven with high output at the time of low-speed running, and a steering at a high resolution is enabled at the time of fast-speed running. An electric power steering device causes the electric motor to generate auxiliary torque in accordance with the largeness of steering wheel torque by the steering operation of a wheel made by a driver and reduces the steering wheel torque to the driver. A control device drives, based on a vehicle-speed signal (Vs) from a speed sensor, the electric motor with high output at the time of low-speed running, and enables steering at a high resolution at the time of fast-speed running without increasing an electric-motor output.

Abstract: A control device controls a switching operation of a switching element such that an AC voltage allowing an AC motor to output torque in accordance with a torque command value is applied to a coil winding of each phase. The control device sets a gate resistance variably between a first pulse voltage at the time of reversal of polarity of the AC voltage and a remaining pulse voltage, in a drive circuit for turning on/off the switching element in response to a switching control signal. By making longer a time period for the first pulse voltage at the time of reversal of polarity to rise, occurrence of partial discharge in a gap between coil windings of respective phases is suppressed.

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 fan drive apparatus includes a first fan, a second fan configured to form an air flow space, which has an intake side and an exhaust side, in cooperation with the first fan, a first drive circuit and a second drive circuit configured to output drive voltages to drive the first fan and the second fan respectively, a current detection unit configured to detect a drive current for the second drive circuit when the first fan and the second fan are driven, and a control unit configured to control the second drive circuit to change the drive voltage applied to the second fan, and determine a drive voltage so that a variation amount of the drive current detected by the current detection unit with respect to a change of the drive voltage is equal to or less than a predetermined value.

Abstract: A drive control signal is effectively obtained. An offset control circuit (32) adds an offset to a rotational state signal.

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: Systems, methods, and devices are disclosed, including an induction-motor controller having a phase path; a solid-state switch interposed on the phase path; and a controller coupled to the solid-state switch. In certain embodiments, the controller is configured to switch the solid-state switch so that the solid-state switch is conductive during a conduction angle of a cycle of an incoming AC power waveform conveyed by the phase path, calculate the conduction angle based on a generally sinusoidal reference value that has a frequency lower than a frequency of the incoming AC power waveform, and adjust the generally sinusoidal reference value based on a value indicative of flux in a load coupled to the phase path.

Abstract: The present invention relates generally to systems and methods for detecting ground faults (i.e., line-to-ground faults) in electrical power conversion systems. In particular, the embodiments described herein include a common mode voltage booster module configured to calculate a common mode voltage boost factor and a common mode voltage boost function based on a plurality of voltage commands for the system. The common mode voltage boost factor and/or the common mode voltage boost function may be applied to the voltage commands to generate boosted voltage commands which, when applied to an inverter or converter, source current indicative of ground faults in the system. More specifically, the common mode voltage boost factor may be multiplied by a common mode voltage calculated by a common mode voltage calculator and summed with the voltage commands.

Abstract: A controller for rotating electrical machines comprises a processing unit, to which a plurality of parameters are input, for generating a switching instruction to control a switching operation of a switching semiconductor device and outputting a signal corresponding to the switching instruction to a power converter. The processing unit includes at least a function to input thereto signals having been output from each of sensors such as a current sensor to detect current passed between the power converter and a winding of an armature, a temperature sensor to detect temperature of the winding of the armature, and a magnetic pole position sensor to detect magnetic pole position of a magnetic field system, and, based upon information on current, temperature, and rotation speed of the rotating electrical machines, having been obtained from those sensor signals, detects a magnetic flux that interlinks with the winding of the armature from a permanent magnet.

Abstract: A motor control method for an MDPS system makes it possible to provide smoother and easier steering operation at a low cost by improving the OHP performance while supplying appropriate controlling electric current to a motor, without changing the motor or a decelerator used in an MDPS system.

Abstract: A control apparatus for an alternating-current motor that is driven by an inverter includes a rectangular wave voltage control portion that generates a control command of the inverter such that rectangular wave voltage that has been phase-controlled to make the alternating-current motor operate according to a torque command value is applied to the alternating-current motor; and a phase change control portion that controls a change in the phase to maintain the center of a flux linkage vector locus indicative of a change in a flux linkage of the alternating-current motor before and after a change in the phase of the rectangular wave voltage.

Abstract: A ripple detection unit detects a ripple current width of a motor current controlled according to PWM control. A ripple reference setting unit sets a reference value of the ripple current width. A frequency adjusting unit sets a control signal indicating a carrier frequency of the PWM control according to a ripple current width deviation. A carrier generation unit generates a carrier of the frequency based on the control signal. Thus, it is possible to realize feedback control of the carrier frequency for maintaining the ripple current width at an appropriate level.

Abstract: An inverter controller comprising an AC motor as a load. A rectifying circuit converts AC power from an AC power source into DC power. A smoothing capacitor smoothens a DC voltage from the rectifying circuit. An inverter circuit converts DC power supplied via the smoothing capacitor into a desired frequency. A current detection circuit detects a output current of the inverter circuit. A voltage detection circuit detects a terminal voltage (Vpn) of the smoothing capacitor. A voltage command calculation circuit calculates a voltage command to the AC motor. A speed command calculation circuit calculates a speed command to be used when it is determined that the AC power source is in a power failure state or when the terminal voltage (Vpn) reaches a certain value.

Abstract: A control system for an AC motor determines a slope Ktl of a tangent TL at an operating point Pa corresponding to the current motor operating state and voltage phase (?0) on a torque characteristic curve that is plotted according to a torque equation representing an output torque characteristic with respect to the motor operating state and the voltage phase of the rectangular wave voltage. The control system further calculates a voltage phase change amount ?ff for use in feed-forward control, according to ?Ttl/Ktl obtained by dividing a torque compensation amount ?Ttl for feed-forward control by the slope Ktl.

Abstract: A controller is capable of executing direct couple control that directly couples a first power device and a second power device without causing a DC/DC converter to convert voltage. During the direct couple control, a drive signal that causes no voltage conversion is intermittently output to at least one of a plurality of switching devices.

Abstract: According to one disclosed embodiment, a gate driver circuit for sensorless speed detection and driving a switching stage includes high side and low side switches series connected across a DC bus and having a switching node between the series switches, the gate driver having a bootstrap power supply for powering a high side driver driving the high side switch of the switching stage and a low side driver power supply, and further includes a comparator circuit to periodically compare the voltage between the bootstrap and low side driver power supplies with a threshold and to output a first signal, wherein the first signal indicates current sign and frequency.

Abstract: A motor drive device (100) includes a boost converter (12) boosting a power supply voltage and outputting a boosted voltage; an inverter (14) receiving the boosted voltage from the boost converter (12) and driving a motor (M1); and a controller (30) giving a target value of the boosted voltage to the boost converter (12) and setting one of a rectangular-wave control and a non-rectangular-wave control as a control method of the inverter (14). The controller (30) is capable of selecting from a first operation mode for giving a first boosted target value and designating the non-rectangular-wave control as the control method and a second operation mode for giving a second boosted target value lower than the first boosted target value and designating the rectangular-wave control as the control method, in response to a same predetermined input signal indicating a torque request.

Abstract: A method of power control for an electrical motor using open-loop principles is disclosed. The method employs a desired control line function that determines hold-off time based on a detected phase lag of a motor drive signal. The motor to be controlled is driven with a motor drive signal at a given load for a first number of cycles to detect the phase lag of the motor drive signal. Controlling for phase lag for a second number of cycles is then accomplished by firing a thyristor according to the phase lag of the motor drive signal. Advantages include reduced power consumption of a motor controlled by an embodiment of the method or controller, and faster response time between the detection of load changes on the motor and the issuance of power control signals.

Abstract: A motor control device includes a motor current detector for detecting motor current flowing in a three-phase motor based on current flowing between an inverter driving the motor and a DC power supply, a specified voltage vector generating portion for generating a specified voltage vector indicating a voltage vector to which an applied voltage to the motor should follow based on a magnetic flux linkage of an armature winding of the motor, a specified voltage vector correcting portion for correcting the generated specified voltage vector, and a magnetic flux estimating portion for estimating the magnetic flux linkage based on the motor current and the specified voltage vector after the correction. The motor control device controls the motor via the inverter in accordance with the specified voltage vector after the correction.

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: An induction motor controller that may include three phase paths leading from a power input to a power output, a solid-state switching device interposed between the power input and the power output on each of the three phase paths, a voltage sensor coupled to two of the phase paths between the solid-state switching device and the power input, a current sensor on one of the phase paths, a processor communicatively coupled to the voltage sensor, the current sensor, and the solid state switching device; and a memory coupled to the processor. The processor may be configured to calculate a motor parameter based on a signal from the voltage sensor and a signal from the current sensor and store the calculated motor parameter in memory.

Abstract: A method for testing a motor having a rotor and a winding is provided. The method includes steps of (a) providing a power to rotate the rotor to a predetermined speed, (b) removing the power, (c) measuring a terminal voltage of the winding while a current within the winding is zero, (d) obtaining a back electromotive force in the winding by compensating the terminal voltage with a performance of the rotor, (e) selecting a characteristic of the back electromotive force and (f) determining a magnetization of the motor by comparing the characteristic with a predetermined parameter.

Abstract: An integrated circuit for controlling a DC motor is disclosed. The integrated circuit includes at least one digital position and speed circuit (DPS) for providing measurements of speed, position, and direction of the motor, the DPS being in signal communication with the motor for receiving a pair of signals having a quadrature relationship; and at least one programmable gain amplifier (PGA) electrically coupled to the motor, the PGA being configured to receive a feedback signal indicative of current flowing through the motor and to apply a second signal to the motor for adjusting the speed of the motor; and at least two analog-to-digital converters (A/D), one A/D being used to quantize the output of the PGA for an off-chip processor; and another A/D to provide motor reference position from an analog sensor, such as a potentiometer; and at least two digital-to-analog converters (D/A), one D/A used to set the motor voltage; and another D/A used to set the motor current limit.

Abstract: A voltage type inverter apparatus comprising a voltage correcting portion. The voltage correcting portion corrects a given voltage instruction based on a value generated by passing a direct current bus voltage detected value through a first degree delay filter. In decelerating a speed of the alternating current motor, the speed is decelerated in an overexcited state by multiplying the given voltage instruction by a set gain. Simultaneously, a time constant of the first degree delay filter is made larger than a time constant in a normal control state.

Abstract: A square wave voltage having an amplitude equal to an output voltage of a converter is applied to an AC motor by a square wave control block. Torque control of the AC motor is performed basically by changing the voltage phase of the square wave voltage according to the torque deviation. When the motor revolution is suddenly changed, a instruction value correction unit sets a voltage instruction value of the output voltage of the converter according to a change ratio of the motor revolutions. This improves control of the motor current by changing the voltage applied to the motor in accordance with the sudden change of the motor revolutions without waiting for torque feedback control having a low control response.

Abstract: A power accumulating unit of a power supply system includes a first switch section configured to achieve a first voltage output state in which an output voltage is substantially equal to a first motor driving voltage and a second switch section configured to achieve a second voltage output state in which the output voltage is substantially equal to a second motor driving voltage that is higher than the first motor driving voltage. A voltage switching control part is configured to perform a voltage switching control to switch between the first motor driving voltage and the second motor driving voltage by alternately operating the first and second switch sections to repeatedly switch between the first voltage output state and the second voltage output state.

Abstract: An induction motor controller that may include three phase paths leading from a power input to a power output, a solid-state switching device interposed between the power input and the power output on each of the three phase paths, a voltage sensor coupled to two of the phase paths between the solid-state switching device and the power output, a current sensor on one of the phase paths, a processor communicatively coupled to the voltage sensor, the current sensor, and the solid state switching device; and a memory coupled to the processor. The processor may be configured to calculate a motor parameter based on a signal from the voltage sensor and a signal from the current sensor and store the calculated motor parameter in memory.

Abstract: The present invention provides an induction motor controller which includes: a circuit for generating a d-axis current reference signal from a d-axis current command value and a periodically varying periodic signal; a d-axis current controller for controlling a d-axis motor current flowing through an induction motor to be controlled to match the d-axis current reference signal; parameter determining means for calculating and determining a motor parameter of the induction motor based on a deviation of the d-axis motor current from the d-axis current reference signal, and controlling a voltage applied to the induction motor using a compensation voltage calculated from the calculated and determined motor parameter, in which a control parameter for controlling the induction motor is set based on the calculated and determined motor parameter.

Abstract: Apparatus and methods for phase current detection used for driving a motor by supplying outputs from a pulse width modulation (PWM) converter to the motor. One method presented provides detecting a DC link current and a vector pattern, determining whether a voltage vector lengths exceeds a predetermined value, and adjusting the voltage vector by adding a positive or reversed voltage based upon the above determination and an integrated error value.

Abstract: An actuator drive circuit includes a counter starting counting of a frequency-divided clock obtained by dividing a frequency of a reference clock in response to an activation signal, a D/A converter providing a converted voltage increasing gradually and stepwise in response to an output of the counter, a coil current control amplifier comparing a coil current detection voltage corresponding to a value of a coil current of the actuator with the converted voltage immediately after activation, comparing the coil current detection voltage with a coil current limitation reference voltage corresponding to an upper limit value of the coil current after the converted voltage matches the coil current limitation reference voltage, and providing an amplified output voltage prepared by amplifying a difference between the compared voltages, and a drive current output circuit providing a drive current of the actuator according to the amplified output voltage of the coil current control amplifier.

Abstract: The invention concerns a motor starter circuit for an induction motor, particularly a single-phase AC induction motor, with a main winding (4) and an auxiliary winding (5) supplied with current, particularly AC, via current supply connections (24, 25), and with a starter switch arrangement (15), which serves the purpose of interrupting the current flow through the auxiliary winding (5) after the start of the motor, the starter switch arrangement (15) interacting with a measuring arrangement serving the purpose of measuring the voltage across the auxiliary winding (5).

Abstract: An elevator control device that drives a cage in a high-efficient speed pattern without using a load detector such as a conventional scale device. The elevator control device includes: a current detector for detecting a current that is supplied to a motor from an inverter; a speed detector for detecting a rotation speed of the motor; a speed pattern generator for generating an elevator speed pattern; a motor speed control device for controlling the speed so that a speed detection value follows a speed command value of the speed pattern; and a motor current control device for controlling a current that is supplied to the motor with respect to the inverter by using a current detection value and the speed detection value on the basis of the speed command value.

Abstract: Indirect rotor resistance estimation for an AC induction motor is achieved by successively stepping the quadrature command to zero and the direct current command to a predetermined value causing the quadrature stator voltage to decay as a representation of rotor current decay; defining, in response to the decaying stator voltage reaching two spaced thresholds, a voltage/time difference, and retrieving from a storage device the rotor resistance associated with the voltage/time difference.

Abstract: The invention relates to a three-phase asynchronous electric motor for domestic appliances, comprising power elements, such as triacs or relays, for charge control. The power elements other than the relays are controlled by at least one microcontroller with the aid of an optical insulation means, ensuring electronic programming and also control of the motor with the aid of a command. The microcontroller or microcontrollers are references to a zero potential of a recovery and filter block feeding the motor. The controller can be applied to a washing machine in order to control the electric motor which rotationally drives the drum.

Abstract: Methods and apparatus are provided for preventing a voltage overload condition of an alternating current (“AC”) motor electrically coupled to an inverter. In an embodiment, the system includes an oil pump, a motor in communication with the oil pump, an inverter module in electrical communication with the motor, the inverter module configured to generate a speed command, and a controller module. The controller module is in communication with the inverter module and the motor and is configured to determine an error, based, in part, on an estimated torque value of the motor and a predetermined maximum available torque value, to convert the error into a first value, to limit the first value between a negative value and zero, and to add the first value to the speed command from the inverter to thereby generate a final speed command for the motor.

Abstract: In a method for measuring motor speed and position by detecting the back-EMF generated during pole-pair interactions, fluctuations of a three-phase motor power supply that may affect back-EMF detection are reduced. One phase of the power supply is tristated for a certain interval preceding and during back-EMF detection. For a shorter interval during back-EMF detection, the voltage drop across the motor is reduced from the full power supply voltage. This preferably is accomplished either by pulling a first of the other two power supply phases low, while pulling a second of the other two power supply phases up to a regulated voltage below the power supply voltage, or by pulling the second of the other two phases up to the power supply voltage and pulling the first of the other two phases down to a regulated voltage above ground.

Abstract: In regenerative braking mode, an inverter converts, according to PWMC signal from a control unit, an AC voltage generated by a motor into a DC voltage to supply the converted DC voltage to an up-converter which down-converts the DC voltage to charge a DC power supply. The control unit receives voltage V2 from a voltage sensor to stop the up-converter if voltage V2 is higher than a predetermined value. The control unit further receives voltage Vf from a voltage sensor that is applied to a DC/DC converter and stops the up-converter if voltage Vf is higher than a predetermined value. Moreover, the control unit receives voltage V1 of the DC power supply from a voltage sensor to stop the up-converter if voltage V1 does not match voltage V2.