Abstract: A motor unit and a vehicle equipped with the unit according to the invention includes a control unit that selects a switching frequency, that is, a carrier frequency, in accordance with a rotation speed of the motor and a torque required from a motor. When an inverter temperature becomes high, the control unit limits the torque of the motor to suppress further increase in the inverter temperature. A limit value used in restricted operation is determined in accordance with the temperature and the carrier frequency of the inverter.

Abstract: A system and method for precharging a harmonic filter connected to a power supply line to receive AC power and deliver the AC power to the motor drive unit includes a control circuit. The control circuit is configured to monitor an operational state of the motor drive unit or the power supply line, and generate a first control signal upon a predetermined change in the operational state and a second control signal delayed from the first control signal. The system also includes a charging circuit having a first switch configured to actuate in response to the first control signal to provide a reduced power to at least a portion of the harmonic filter and a second switch configured to actuate in response to the second control signal to provide a non-reduced power to the at least a portion of the harmonic filter.

Abstract: A low cost switching system for an electrical motor, which is speed sensitive, direction of rotation insensitive, load insensitive and voltage fluctuation insensitive. The switch contains a power supply, a control circuit, a zero cross detector circuit, a triggering circuit and an electronic switch to provide the switching action. A time delay hysteresis inducement circuit is provided in the switching system to energized and deenergized the capacitor at a predetermined synchronous speed of the motor. The switching system first checks the speed of the motor before reenergizing the start capacitor, which increases the life of the motor. The switching system operates in high temperature range and regardless the value of the capacitor used.

Abstract: A control architecture for an electrical inverter includes a command limiter that is realized as a circular voltage limiter. The command limiter includes a Cartesian-to-polar converter coupled to a command source such as a synchronous frame current regulator. The Cartesian-to-polar converter provides magnitude and phase components for d-q command voltages. The command limiter further includes a magnitude limiter that limits the magnitude component to the maximum fundamental voltage component of the inverter, and a polar-to-Cartesian converter that converts the limited magnitude component and the phase component into modified d-q command voltages.

Abstract: A method and associated apparatus for operating an electrical machine includes providing a brushless excitation system including at least one rectifier having at least one diode. The method also includes providing at least one voltage amplitude limiter assembly including at least one resistor and at least one transient voltage suppressor (TVS) electrically coupled with the at least one resistor to form at least one voltage suppression unit. The method further includes transmitting an electrical signal having a current and a voltage to each voltage suppression unit, the voltage having an amplitude. The method also includes electrically coupling the at least one voltage amplitude limiter assembly to the at least one diode. The method further includes transmitting the electrical signal through the rectifier and the voltage suppression unit such that voltage amplitude excursions of the electrical signal are facilitated to be reduced.

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: There is provided a controller for a motor capable of changing the phase difference between two rotors that can prevent demagnetization of permanent magnets or the rotors. The motor has two rotors each having a permanent magnet and phase difference changing driving means for changing the phase difference between the rotors. The controller has a demagnetization determining means for determining whether or not demagnetization of the permanent magnets of the rotors occurs during operation of the motor, and rotor phase difference controlling means for controlling the phase difference changing driving means to change the phase difference between the rotors from a current phase difference to a phase difference that results in a higher strength of a composite field of the permanent magnets if the result of determination by the demagnetization determining means is positive.

Abstract: A method and apparatus to provide estimates of electrical parameters for line-connected induction motors during either steady-state or dynamic motor operations. The electrical parameters are calculated from the motor nameplate data and voltage and current measurements. No speed sensors or electronic injection circuits are needed. The method can be divided into 4 major steps. First, complex space vectors are synthesized from voltage and current measurements. Second, the instantaneous rotor speed is detected by calculating the rotational speed of a single rotor slot harmonic component with respect to the rotational speed of the fundamental frequency component. Third, the positive sequence fundamental frequency components are extracted from complex space vectors. Finally, least-squares estimates of the electrical parameters are determined from a dynamic induction motor equivalent circuit model.

Abstract: Method for operating a delta wound three-phase permanent magnet brushless motor. A transition speed is determined in a quadrant of a speed versus torque curve above which speed continues to increase while current/torque decreases wherein actual phase current can be controlled in a current control modification manner which reduces requested phase current. The modification manner is determined for a quadrant, wherein a controller can use the modification manner to reduce the requested phase current to control the actual phase current when the speed is above the transition speed. The motor is controlled in a quadrant wherein, when the motor has a speed above the transition speed, the controller reduces the requested phase current in the modification manner and the controller supplies the actual phase current to the motor using the reduced requested phase current and using measured phase current of the motor derived from using a single current sense resistor.

Abstract: A magnetizing motor having a permanent magnet body covering an outer circumferential surface of a rotor body, includes a speed detecting unit that detects a speed of the magnetizing motor; and a controlling unit that compares the speed detected by the speed detecting unit with a reference speed, and outputs a magnetizing control signal based on the result of the comparison.

Abstract: In a control apparatus for an electric vehicle, an input power operation quantity that reduces the difference between a target value of a system voltage and a detected value of the voltage is computed, and a duty ratio of a rectangular waveform applied to an inverter is set at a value that changes the input power of a MG unit by the input power operation quantity. The phase of the rectangular waveform is set at a value that suppresses torque variations caused by the duty ratio as variations of a torque generated by the AC motor. 3-phase voltage command signals are computed on the basis of the phase and the duty ratio and supplied to the inverter. In this way, variations in system voltage can be suppressed by controlling the input power of the AC motor, while sustaining the torque generated by the AC motor unchanged.

Abstract: The present invention relates to a control method for a synchronous electric motor with permanent-magnet rotor, particularly for fluid circulation pumps in conditioning systems and/or household appliances, wherein the application of predetermined voltage values to each of the windings (L1, L2) of the motor is provided, by means of a converter control circuit (10). The method provides a continuous measure of the amplitude of the bus (Vr) ripple and a comparison with a reference value, for example with respect to an average bus voltage level. According to the comparison result the motor is driven by means of a variation of the winding voltage having an sinusoidal wave form.

Abstract: A controller of a permanent magnet type rotary motor of the present invention includes: a current difference calculator decomposing a primary voltage difference which is a difference between a primary voltage of the permanent magnet type rotary motor and a maximum voltage corresponding to a source voltage, into a field-axis voltage difference component and a torque-axis voltage difference component in the rotatory magnetic flux coordinate by the use of a phase angle of the primary voltage, and calculating a field-axis current difference component and a torque-axis current difference component in the rotatory magnetic flux coordinate by the use of the voltage difference component, a field-axis inductance, and a torque-axis inductance; and a target current corrector correcting a field-axis target current and a torque-axis target current in the rotatory magnetic flux coordinate so that current difference components are zero.

Abstract: A controller for a brushless motor determines difference between target currents and detected currents in a dq coordinate system and determines a target voltage applied to an armature winding based on a feedback calculation, such as PI (Proportional Integral) calculation, P (Proportional) calculation, or PID (Proportional Integral Derivative) calculation, to decrease the differences.

Abstract: A vector control apparatus for a permanent magnet motor operated in the region of weak magnet field, wherein when the output voltages of the power converter saturate, the phase error command value represented by the difference between the angular position of the reference axis for control and the angular position of the motor magnetic flux axis is generated on the basis of the difference between the q-axis current command value and the detected value of the q-axis current, and the command values for the output voltages of the power converter are corrected by using the phase error command value, whereby a highly responsive torque control with high precision can be achieved.

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: A method and a system in connection with a speed and position sensorless permanent magnet synchronous machine equipped with an output filter and driven by an inverter, which method comprises the steps of forming a speed-adaptive full-order observer based on the dynamic model of the combination of the permanent magnet synchronous machine (PMSM) and the output filter, measuring the inverter output current (iA), estimating inverter output current (îA), determining the estimate for the electrical angular speed ({circumflex over (?)}m) using the estimated and measured inverter output currents (îA, iA) in an adaptation law, injecting a voltage signal (uc) into the inverter voltage reference (uA,ref 0) to obtain a modified voltage reference (uA,ref), detecting an error signal (?) from the measured inverter output current (iA), and calculating the speed correction term (??) used in the adaptation of the observer from the error signal (?).

Abstract: The invention relates to a control apparatus of an electric power steering apparatus structured such as to apply a steering assist force generated by a n-phase motor to a steering system of a vehicle, the control apparatus is provided with at least (n?1) numbers of current detecting means for detecting a current Im in each of phases of the motor, a current command value calculating means for outputting a current command value Imref in each of the phases, and n numbers of current control means, and the control apparatus executes a current control of each of the phases by the current control means having the current command value Imref in each of the phases and the current Im in each of the phases as an input.

Abstract: An object of the present invention is to provide a driver for an induction motor which performs an operation at an acceleration suitable for the magnitude of a load and is excellent in efficiency, without an acceleration failure. The driver for an induction motor includes a slip frequency estimate value arithmetic operation section 15 for arithmetically operating a slip frequency ?s^ of an induction motor 12, and a maximum torque generation slip arithmetic operation section 16 for arithmetically operating a slip frequency ?smax at which a maximum torque is generated. When the slip frequency ?s^ exceeds a predetermined value ?smaxTH (=0.9 ?smax, etc.) corresponding to the slip frequency ?smax at which the maximum torque is generated, a speed change rate arithmetic operation section 17 and a speed change rate correcting section 18 reduce a rate of increase in a speed command ?r*.

Abstract: The present invention relates to a parameterization method for a converter (1, 2) of the speed controller type, the said converter (1, 2) being connected to an electrical load (3) by means of an electrical cable (4) comprising at least two conductors, the method consisting in: generating common-mode current on the electrical cable (4) starting from a pulsed voltage comprising a first voltage edge (11, 13) and a second voltage edge (12, 14) delayed by a delay time (T) with respect to the first voltage edge (11, 13), measuring the common-mode current generated, making the delay time (T) between the two voltage edges (11, 12, 13, 14) generated vary, and determining an optimal delay time (T2) starting from a quantity (Ipeak, Ieff) representative of the common-mode current measured for the various values of the delay time (T).

Abstract: A control device for controlling a motor includes a sensing module, a modifying module and a driving module. The sensing module senses the motor to generate a sensing signal. The modifying module receives the sensing signal and generates a phase modifying signal according to the sensing signal. The driving module receives the phase modifying signal and generates a driving current to drive the motor according to the phase modifying signal.

Abstract: This invention relates to low loss power supply system comprising a rectifying bridge (3) supplying current to a motor, wherein the rectifying bridge including two AC power feed inputs PA, PB as well as at least one output for supplying power to said motor M, and wherein an YD transformer (2) is coupled between said inputs, said YD transformer, comprising a star and delta winding, and being adapted to provide an approximately 30° phase shift relative to the chosen fundamental frequency between said inputs.

Abstract: A method, computer-readable code, and controller are provided for controlling a cycle-skipping control system having two or more cycle skippers connected to a common multi-phase AC (alternating current) power source to drive a variable frequency load. A respective firing sequence is generated to be applied to a plurality of power switches in the two or more cycle skippers for implementing a desired mode of operation. A phase angle shift is provided between each respective firing sequence to be applied to the two or more cycle skippers over a firing cycle. This enables a non-concurrent firing for each cycle skipper over the firing cycle.

Abstract: A motor control device includes an estimator for estimating a rotor position of a motor having a salient pole by using a value corresponding to a q-axis inductance of the motor as an operation parameter where an estimated axes for the control corresponding to d-q axes are ?-? axes, and a controller for controlling the motor based on the estimated rotor position. The estimator generates a deviation between a d-axis and a ?-axis by performing the estimation of the rotor position based on a value between a real q-axis inductance and a real d-axis inductance of the motor adopted as the operation parameter. The controller controls the motor so that a ?-axis component of a motor current supplied to the motor is maintained to be a predetermined value of zero or close to zero regardless of a value of a ?-axis component of the motor current.

Abstract: A motor control apparatus 1 that controls a rotation speed of a motor driven according to a speed command includes an abnormal-rotation detector 21 which determines that the motor is in an abnormal-rotation state, such as a runaway, when a speed deviation Ver obtained by subtracting a detection speed TSA of a motor rotation from a speed command VCMD is equal to or larger than a threshold value, when a sign of a product of acceleration ?TSA obtained by subtracting a last detection speed from a detection speed this time that is detected in a predetermined cycle and a torque command Tc obtained by proportionally integrating the speed deviation is negative, and when an integration value VerSUM of the speed deviation Ver exceeds a predetermined value ALMlevel. With this arrangement, an abnormal rotation of the motor can be instantly detected even during acceleration or deceleration of the motor, thereby increasing the performance of protecting the motor.

Abstract: An electric drive control apparatus and method calculates a current command value based on an electric machine target torque that represents a target value of a torque of an electric machine; calculates a current deviation between the current command value and a current applied to the electric machine; calculates a first inductance and a second inductance that each have a different amount of change caused by a change in the current; calculates an interference term based on the first inductance; calculates a proportional term and an integral term based on the current deviation and the second inductance; and calculates a voltage command value based on the interference term, the proportional term and the integral term.

Abstract: A controller for a motor performs field weakening control by changing a phase difference between two rotors, which are concentrically disposed, and by accurately recognizing the phase difference.

Abstract: The drive circuit (10) includes a processing and control circuit (14) comprising a protection circuit (16), designed to generate at its output a logical inhibiting signal (C) starting from every zero crossing of the motor supply volts (V), the inhibiting signal (C) having a predetermined duration (t0) which is less than a quarter of the period of the supply voltage (V); and an enabling circuit (17), connected to a sensor of the position of the rotor (6) and designed to enable a first and a second controlled conduction device (12, 13) associated with the stator winding (4) to conduct current alternately, in synchronization with the signal (H) supplied by the position sensor (6). The enabling circuit (17) is connected to the protection circuit (16) in such a way that the conduction of current through the controlled conduction device (12, 13) enabled at any time is inhibited for the duration (t0) of the inhibiting (C).

Abstract: A clean engine for transportation, generators, and other applications. It comprises a series of alternating support wheel assemblies and magnet wheel assemblies that are propelled in a consistent pattern by battery powered electromagnets. The engine comprises at least one support wheel assembly and at least one magnet wheel assembly. The support wheel assemblies and magnet wheel assemblies are aligned in a specific pattern along a main shaft that is supported on each end by sealed bearings mounted in a nonmagnetic housing.

Abstract: A control method and a controller for an a.c. motor without using a speed sensor in which the speed estimated value or the magnetic flux estimated value of an all-dimensional magnetic flux speed observer can be made to correspond to that of an actual a.c. motor.

Abstract: An induction motor having a reverse-rotation preventing function, comprises: a stator provided with a winding coil generating flux by a current; an induction rotor provided with a cage and rotatably inserted in the stator, wherein a rotary shaft is coupled to its inside; a synchronous rotor provided with a permanent magnet and rotatably coupled between the stator and the induction rotor; an induction-force generating unit generating a force for moving the synchronous rotor in an axial direction; and a rotation preventing unit preventing a reverse rotation by fixing the synchronous rotor moved by the induction-force generating unit at the time of reverse rotation of the synchronous rotor.

Abstract: A control apparatus for an electric motor, in which a current controller giving multiphase voltage commands to a drive circuit for an inverter includes a normal-mode current controller for use in a normal mode, an abnormal-mode current controller for use in an abnormal mode, and an abnormality decision device. In a case of an abnormality occurring to one phase of an electric motor or the inverter, the controller is altered, and the abnormal-mode multiphase voltage commands which are generated by the abnormal-mode current controller are set as the multiphase voltage commands for the inverter drive circuit.

Abstract: The hybrid induction motor includes a housing; a stator installed in the housing and having a stator core portion and a stator coil portion; a rotor coupling body having a rotary shaft rotatably installed in at the housing, a cage rotor portion rotating integrally with the rotary shaft, and a permanent magnet rotor portion coupled to a circumference of the cage rotor portion with a certain air gap so as to rotate freely with respect to the rotary shaft; and a reverse rotation preventing switch, when the rotary shaft rotates reversibly, coming in contact with the permanent magnet rotor portion which is moved along the shaft by thrust generated by the rotor coupling body and cutting off power being supplied to the stator coil portion.

Abstract: A detailed architectural and operational characteristic of a pulse code width modulation (PCWM) motor drive system is presented. The system can drive a three phase permanent magnet AC (PMAC) motor sinusoidally without sensing its rotor position. The system employs an ultrasonic carrier frequency (e.g., of approximately 20 kHz) to avoid annoying acoustic noise problems. While keeping the hardware construction at a minimum, it can provide the highest possible motor performance by satisfying various motor operating requirements. The system may include an AC to DC converter, an application specific integrated circuit (ASIC), a DC to DC step-down chopper, and a gate drive and power transistor circuitry to drive a three phase AC motor.

Abstract: An object of the present invention is to provide an electric vehicle control device which is capable of detecting even a state in which only one phase of one induction motor is disconnected in a system where a plurality of induction motors are connected in parallel with each other and driven by one vector-controlled inverter device.

Abstract: A solar cell production system utilizes self-contained vacuum chucks that hold and cool solar cell wafers during transport on a conveyor between processing stations during a fabrication process. Each self-contained vacuum chuck includes its own local vacuum pump and a closed-loop cooling system. After each wafer is processed, it is removed from its vacuum chuck, and the vacuum chuck is returned to the start of the production line by a second conveyor belt. In one embodiment, each vacuum chuck includes an inductive power supply that is inductively coupled to an external source to drive that vacuum chuck's vacuum pump and cooling system. An optional battery is recharged by the inductive power supply, and is used to power the vacuum pump and cooling system during hand-off between adjacent processing stations.

Abstract: A control system for a hybrid powertrain which determines engine crank angle position based upon signal inputs from electric machines of the powertrain is provided. The hybrid powertrain comprises an internal combustion engine and electric machines and an electromechanical transmission selectively operative to transmit torque therebetween. The electric machines are rotatably fixedly coupled to the internal combustion engine via a transmission input shaft. Control modules are adapted to execute a control scheme to determine engine crank angle position. The control scheme comprises code to determine an input shaft angle based upon rotational positions of the electric machines. An offset angle of the input shaft and an angular twist between the engine and the transmission are determined. An engine crank angle offset is determined based upon the offset angle and the angular twist of the input shaft.

Abstract: A motor control module for a power tool includes a controller and a triac for controlling current to the given tool motor. The module includes a circuit within the controller for implementing a plurality of control methodologies related to synchronizing the module to the AC input signal, estimating average current flowing through the triac, compensating for amplifier offset to improve accuracy of current measurements in the module, and providing speed measurement and control for the tool motor using principles of hysteresis in a comparator of the controller. Additionally, the controller is configured to calibrate an oscillation calibration register therein.

Abstract: A normal map determines a carrier frequency used for switching control of an inverter controlling driving of a motor generator, in accordance with the state of operation of the motor generator in a normal operation. In a stall state in which the driver is pressing both the accelerator pedal and the brake pedal, the switching frequency is determined using an element protection map, in place of the normal map. When the element protection map is used, in the state of operation corresponding to the stall state, the carrier frequency is set to a protection frequency lower than a normal frequency. Therefore, in an electric vehicle having an electric motor (motor generator) as a driving source for the vehicle, it becomes possible to avoid temperature increase of a power semiconductor device forming an electric power converter for controlling driving of the electric motor.

Abstract: An electronic device is provided for controlling a motor having three phases driven by a motor driver. In one implementation, the electronic device includes a detection means and a control circuit. The detection means includes three high-gain differential amplifiers and three A/D converters. The detection means detects back EMF voltages induced by the rotation of the motor and applies corresponding signals to the control circuit. The control circuit computes and filters the position and/or the speed of the motor and then delivers the filtered values of the computed rotor position and/or speed to control the motor driver. The motor may thus be controlled even at near-zero rotational speed.

Abstract: A CPU calculates, based on a frequency command value for driving a motor and on a state quantity of the motor, an output-voltage command value in which only the phase advances while amplitude is constant in each calculation period, without reducing the calculation period. An ASIC reflects the output-voltage command value in a triangular wave signal in a time-series order to compare with each other, and outputs a PWM signal to a switching circuit. Thus, a waveform of an output voltage is made close to a sine wave irrespective of an output frequency being high or low, and a processing load of the CPU is reduced.

Abstract: In order to obtain an electromagnetic rotating machine of lightweight and high energy efficiency, which produces big torque for rotating a large-diameter fan, a coil A and coil B as excitation coils are disposed on an inner peripheral surface of a fan casing so as to face an outer circumference of the fan, and a coil M as an armature coil crosses at a central portion and is disposed on the outer circumference of the fan. The relationships |Iai|=|Iai+1| and Iai=?Iai+1, or |Ibi|=|Ibi+1| and Ibi=?Ibi+1 are obtained respectively for the coil A or coil B by a current control device (not shown). Moreover, the coil A and coil B are subjected to excitation control such that the direction of effective electromagnetic force, which is generated by an interaction between an effective magnetic field formed by the coil A and effective induced current applied to the coil M by the coil B, corresponds to the direction of rotation of the fan.

Abstract: A capacitor, inductor, and power line are arranged in a series parallel combination tank circuit that operates over four quarters of a complete cycle. During the first quarter cycle: power is applied to the tank circuit, current flows through the inductor to the capacitor, current is stored in the inductor, and the capacitor is charged. During the second quarter cycle; current is released from the inductor as the capacitor discharges current to another parallel inductor or resistive load. During a third quarter cycle: current flows in the capacitor from the opposite direction, the capacitor is charged, current pushes out from the capacitor to the incoming power line, and current is stored in the inductor. During the fourth quarter cycle: the capacitor discharges in the opposite direction, current parallel to another inductor or resistive load flows in the opposite direction, and the inductor releases current to incoming power line.

Abstract: A device for determining a constant of a rotating machine includes: a test number selector outputting a test number n, selected from 1 to N (N?2), and outputting a phase signal q determined by a predetermined condition that is previously set based on the test number n; a tester for supplying an alternating voltage to the rotating machine induction machine based on the test number n and the phase signal q and outputing a reference phase gain and a 90-degree-delay phase gain based on values of the phase signal q corresponding to 1 to N of the test number n; and a rotating machine constant calculator receiving the reference phase gain and the 90-degree-delay phase gain and then calculating a constant of the rotating machine using the reference phase gain and the 90-degree-delay phase gain.

Abstract: An integrated power and attitude control system and method for a vehicle efficiently supplies electrical power to both low voltage and high voltage loads, and does not rely on relatively heavy batteries to supply power during the vehicle initialization process. The system includes an energy storage flywheel, and a solar array that is movable between a stowed position and a deployed position. The energy storage flywheel is spun up, using electrical power supplied from a low voltage power source, to a rotational speed sufficient to provide attitude control. Then, after the solar array is moved to its deployed position, the energy storage flywheel is spun up, using electrical power supplied from a second power source, to a rotational speed sufficient to provide both attitude control and energy storage.

Abstract: A rise in the power supply voltage as a result of a sudden speed reducing command causing the motor current to flow to the power supply is prevented. The motor drive device has a drive signal generating unit for generating a drive signal by an energizing control unit, PWM control unit, and oscillation unit; a drive unit for producing drive power to drive the motor based on the drive signal; a torque control signal generating unit for generating a torque control signal specifying the motor torque; a speed detection unit for detecting the rotational speed of the motor and generating a rotational speed signal denoting motor speed information; and a decision unit for generating a speed difference detection signal denoting the difference between the torque control signal and the rotational speed signal. The drive signal generating unit is controlled based on the speed difference detection signal.

Abstract: A motor includes: a stator (12) having coils; a rotor (11), which is disposed inside the stator and has a plurality of magnets; and a magnetic path switching part (18), which is provided in the rotor (11) and switches a magnetic path of the rotor (11) to select intense field control as a forward salient-pole structure or weak field control as an inverse salient-pole structure. The magnetic path switching part (18) is formed by use of a member having magnetic anisotropy, which is arranged on a magnetic path connecting magnets (13) of the same pole and a magnetic path connecting magnets (13) of different poles in the rotor (11). By changing the magnetic anisotropy of the member, the forward salient-pole structure and the inverse salient-pole structure are switched therebetween.

Abstract: A vector controller of an induction motor capable of correcting the set value of mutual inductance so as to match it to an actual value by additional processing on software without adding any special device. The vector controller (1) of an induction motor comprises a section (3) for determining the correction value of mutual inductance of an induction motor (15) based on the error between a torque operation value calculated using a measurement of the primary current of the induction motor (15) and a torque command value for the induction motor (15) generated at a torque command generating section, and a vector control section (2) for controlling the induction motor such that the generation torque of the induction motor (15) matches the torque command value by using the circuit constants of the induction motor (15) including the correction value of mutual inductance.

Abstract: A motor controller system includes solid state switches for connection between an AC line and motor terminals for controlling application of AC power to a motor. Voltage sensors sense voltage across each of the solid state switches and AC line voltage. A control circuit controls operation of the solid state switches. The control circuit compares the sensed voltages across each of the solid state switches with the AC line voltage in a non-run mode to determine if there is a shorted solid state switch.

Abstract: A method and apparatus control a power converter (20) of a motor drive system. The power converter (20) is controlled during a first operating mode by applying a current control scheme, which sets power converter commands to control active and reactive current components flowing from the power converter (20) to the motor (30) to achieve desired motor speed; and a fault protection scheme is executed during a second operating mode. The fault protection scheme generates power converter commands to reduce the active current component flowing from the power converter (20) to the motor (30) is substantially zero. The first operating mode will be resumed upon receiving the restart command if the motor speed is above a pre-set shutdown threshold.