Abstract: A direct-current to three-phase alternating-current inverter system includes a three-phase motor, a plurality of switching elements, an inverter circuit for the three-phase motor, a capacitor, a direct-current power source and a control circuit. The switching elements arranged in the inverter circuit serve as upper and lower arms for the respective three phases of the three-phase motor, respectively. The capacitor is connected in parallel to the respective pairs of the upper and lower arms. The direct-current power source is arranged between the neutral-point of the three-phase motor and the respective lower arms or the respective upper arms. The control circuit controls the switching elements such that at least the switching frequency of one pair of the switching elements for one phase through which the current having the greatest value flows is lower than the switching frequencies of the other pairs of the switching elements for the other phases.

Abstract: A power converting apparatus including a power converter that converts a DC voltage into an AC voltage and applies the AC voltage to an AC rotating machine and a control unit that controls the power converter based on an operation command from the outside is provided. The power converting apparatus includes: a first calculating unit that calculates and outputs, from a d-axis current detection value and a q-axis current detection value detected by the AC rotating machine and current command values based on the operation command, first voltage command values to the power converter, magnetic fluxes of the AC rotating machine, and an angular frequency; and a second calculating unit that sets, as an initial value, at least one of the magnetic fluxes and the angular frequency input from the first calculating unit and calculates and outputs second voltage command value to the power converter and an angular frequency.

Abstract: A method for estimating a frequency of a harmonic in an AC current passing to/from an AC machine. The method includes observing an AC current passing to/from an AC machine that includes a stator and a rotor; measuring phase fluctuations in the observed AC current; and using the measured phase fluctuations to estimate a frequency of a harmonic in the AC current. The method includes using the estimated frequency of the harmonic in the observed AC current to estimate a speed of the rotor of the AC machine. The method may be implemented by a controller, which may include a PC and/or a DSP.

Abstract: To provide an upper limit of a generated voltage or generated torque, to thereby prevent the occurrence of an overvoltage or excessive torque during power generation, a control selection section (308) chooses and outputs a minimum value between a control output of a generated voltage control section (306) for controlling a field current so that a B-terminal voltage of a polyphase AC generator-motor coincides with a generated voltage command and a control output of a generated torque control section (307) for controlling, based on the B-terminal voltage and a rotation speed, the field current so that generated torque of the polyphase AC generator-motor coincides with a generated torque command.

Abstract: A controller for a brushless motor that includes an input for receiving an analog signal, an analog-to-digital converter (ADC) for sampling the analog signal, and a processor. The processor starts the ADC during a first electrical half-cycle and reads the ADC during a second electrical half-cycle of the motor. Additionally, a motor system that includes the controller.

Abstract: A system for computing machine parameters of an induction machine includes a relation providing module and a circuit parameter computing module. The relation providing module is operable to provide a relationship between slip rates and primary side resistances of the induction machine and a relationship between the slip rates and primary side reactances of the induction machine. The circuit parameter computing module is operable to perform a parameter computing process according to the relationships obtained from the relation providing module. The parameter computing process includes the steps of: a) generating a set of initial values of equivalent circuit parameters of the induction machine; b) updating the initial values; c) calculating a cumulative resistance error and a cumulative reactance error; and d) repeating steps b) and c) until the cumulative resistance error and the cumulative reactance error are smaller than first and second error thresholds, respectively.

Abstract: A drive for providing high dynamics for a machine, such as a production machine, includes a short-stroke motor, and a pulse-decoupling device for decoupling pulses of the short-stroke motor from the machine using closed-loop control. The pulse-decoupling device has at least one component for use as a working-point adjustment device for adjusting a working point of the short-stroke motor. The pulse-decoupling device is thus able to assume the function of pulse decoupling and in addition, at least partially, the function of working point adjustment.

Abstract: Provided is a drive device for an alternating current motor which performs vector control on sensorless driving of the alternating current motor in an extremely low speed region without applying a harmonic voltage intentionally while maintaining an ideal PWM waveform. A current and a current change rate of the alternating current motor are detected, and a magnetic flux position inside of the alternating current motor is estimated and calculated in consideration of an output voltage of an inverter which causes this current change. The current change rate is generated on the basis of a pulse waveform of the inverter, and hence the magnetic flux position inside of the alternating current motor can be estimated and calculated without applying a harmonic wave intentionally.

Abstract: An object of the present invention is providing permissible values of start currents with sufficiently high start torque ensuring the possibility of the start of a loaded motor, the smoothness of the motor's start, without spikes and fluctuations of the currents, voltages and torques. The other objects of the proposed device are simplicity, reliability and economic efficiency. The proposed method of an induction motor start includes an acquisition of two components of the voltage, feeding the motor. The both components have the different controlled frequencies and root mean square values. The proposed device for an induction motor start comprises two channels forming signals, which create two corresponding components of the motor's feeding voltage.

Abstract: A drive device has a break circuit. The break circuit inputs phase-current values transferred from phase-current sensors mounted on an electrical path of a motor generator. A power switching element is equipped with a freewheel diode connected in parallel with each other. An inverter has pairs of the power switching elements. In each pair, the power switching element in a high voltage side and the power switching element in a low voltage side are connected in series. It is detected for the freewheel diode to be in a freewheel mode when a forward current flows in the freewheel diode. The break circuit detects the freewheel mode where the current flows in the freewheel diode in a lower arm when the phase-current value is not less than a predetermined threshold value. The break circuit detects the freewheel mode where the current flows in the freewheel diode in an upper arm when the phase-current value is not more than the threshold current value.

Abstract: An apparatus for improving machine drive performance. The apparatus includes a controller configured to control an impedance of a converter. The converter is configured to be electrically coupled to a plurality of first ends of a plurality of windings of a machine. A plurality of second ends of the plurality of windings of the machine are configured to be electrically coupled to a power source.

Abstract: A method for controlling operation of a multi-phase induction motor may include transmitting a high-speed operation signal by a master computer for high-speed operation of the motor; receiving the signal by a control signal board, and in response to the signal, the control signal board may sense that the master computer is not simultaneously transmitting a low-speed operation signal, and in response to receiving the high-speed operation signal and not simultaneously receiving the low-speed operation signal, closing delta-to-wye contactors and closing contactors in a power section to transmit power to the motor for high-speed operation, whereby the motor is connected to a source of multi-phase power and operates at high-speed; and the control signal board transmitting a first feedback signal to the master computer that the motor is connected to the source of multi-phase power and is running at high speed.

Abstract: A device for improving efficiency of an induction motor soft-starts the motor by applying a power to the motor that is substantially less than the rated power of the motor then gradually increasing the power 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 phase angle between the voltage and the current to the motor is measured and power to the motor is increasing when the phase angle is less than a minimum phase angle (determined during soft-start) and power to the motor is decreased 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: The present invention relates to an alternating-current electric motor of a combined electric device for powering and charging, the said electric motor being formed by a stator connected to an electricity network of which the number of phases is lower than the number of phases of the said motor, the said charging current of the said network being injected via a connection point dividing each phase of the said stator connected to a phase of the said network into two half-windings, the said motor being characterized in that each half-winding of a phase comprises a plurality of coils wired together so as to reduce the magnetic linkage of each half-winding at the said connection point so that there exists an apparent non-zero inductance at the said connection point in charging mode of the said device.

Abstract: A torque measurement system that includes a rotor device and a stator device can perform automatic tuning to improve the initial tuning performed during design and assembly. The stator device can include a variable capacitive element and a micro-controller configured to adjust a capacitance value of the variable capacitive element. Additionally or alternatively, the rotor device can include a variable capacitive element and a micro-controller configured to adjust a capacitance value of the variable capacitive element. The adjustment of the capacitive elements can be based on the quality of signal detected at either the rotor device or stator device.

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 method for the identification without shaft encoder of magnetomechanical characteristic quantities of a three-phase asynchronous comprising: —constant voltage impression U1? in ? axial direction in order to generate a constant magnetic flux; —test signal voltage supply U1? in ? axial direction of the asynchronous motor, whereby the ? axial direction remains supplied with constant current; —measuring signal current measurement I1? in ? stator axial direction of the asynchronous motor; —identification of mechanical characteristic quantities of the asynchronous motor based on the test signal voltage U1? and on the measuring signal current I1?, whereby the rotor can execute deflection movements. Method can also be used for control of electrical drives. An identification apparatus for the determination of mechanical characteristic quantities of an asynchronous motor and for motor control, whereby the identified characteristic quantities can be used to determine, optimize and monitor a motor control.

Abstract: Identification of electrical equivalent circuit parameters (15) of a three-phase asynchronous motor (09) without a shaft encoder. The method comprises—Assumption of a standstill position of the rotor (11);—Equidirectional test signal infeed U1?, U1? in ? and ? in the stator axis direction of the asynchronous motor (09);—Measuring of a measuring signal I1?, I1? of the ? and ? axial direction of the asynchronous motor (09); and—Identification of equivalent circuit parameters of the asynchronous motor (09) on the basis of the test signal voltages U1?, U1? and of the measuring signal currents I1?, I1?; whereby the test signal feed allows the rotor (11) to remain torque-free. Determination of equivalent circuit parameters (15) of an asynchronous motor (09) as well relates to a motor control device (35), whereby the identified equivalent circuit parameters (15) can be used for the determination, optimization and monitoring of a motor control and for control of electrical drives.

Abstract: A drive control device which estimates an engine torque during traveling in a fixed gear ratio mode is disclosed. The drive control device includes the engagement mechanism including the revolution component revolved by the torque of the engine and the fixed component that engages with the revolution component, the torque applying unit which applies torque to the revolution component and the first transmitting control unit which engages the engagement mechanism to make the engagement mechanism receive the reaction force of the torque. The torque estimating control unit executes control of torque applied to the revolution component by the torque applying unit during executing the control by the first transmitting control unit to detect the phase change between the revolution component and the fixed component and estimates the torque of the engine based on the phase change and torque applied by the torque applying unit.

Abstract: A method and apparatus to drive a load using a pulse-width modulated (PWM) signal and spread a spectrum of the PWM signal across a plurality of frequencies while maintaining a constant duty cycle for the load.

Abstract: A mechanism for a motor controller for engaging a spinning motor is provided. A power section is configured to provide power to the motor. A control is configured to control the power section. The control is configured to search for a motor frequency of the motor by applying a small excitation voltage to the motor, and the excitation voltage is initially applied at a voltage frequency which is a maximum frequency. The control is configured to track the motor frequency until the motor frequency is below an equivalent speed command and engage the motor by applying a higher voltage to the motor.

Abstract: A method of operating an electrical machine is provided. The method includes the steps of providing a brushless excitation system including a diode rectifier having at least one diode, sensing heat energy generated by at least one resistor connected in parallel with the at least one diode, wirelessly transmitting a signal representative of the heat energy, detecting a deviation of generated heat energy from the at least one resistor, and generating a signal indicating an error if the deviation in generated heat energy exceeds a predetermined threshold.

Abstract: A controller for an AC rotary machine which performs a smooth drive from a low-speed region including zero speed to a high-speed region, and which can attain, even if an initial value error is present in an estimated phase, desired characteristics by promptly converging the error.

Abstract: A rotation detecting apparatus for detecting a rotational state of a direct-current motor includes a driving device, a control device, an energization detecting device, an alternating-current component detecting device, and a rotational state detecting device. An impedance between brushes of the motor changes periodically in accordance with rotation of the motor. The alternating-current component detecting device detects change of an alternating-current component of electric current that is supplied to the motor based on an electrical quantity. The change of the alternating-current component is caused by change of the impedance caused in accordance with the rotation. The rotational state detecting device detects at least one of a rotation angle, a rotational direction, and a rotational speed of the motor based on a detection result of the alternating-current component detecting device.

Abstract: A controller outputting a voltage instruction for drive control to a electric rotating machine includes a drive voltage instruction calculation section calculating drive voltage instructions for driving the electric rotating machine, a position estimation voltage generator generating position estimation voltage instructions for position estimation about the electric rotating machine, a noise reduction voltage generator generating noise reduction voltage instructions for reducing noise occurring from the electric rotating machine along with input of the position estimation voltage instructions to the electric rotating machine, and adders outputting, to a voltage application means, a voltage instruction obtained by adding the position estimation voltage instructions and the noise reduction voltage instructions to the drive voltage instructions.

Abstract: The subject matter disclosed herein describes a system for controlling torque in a soft starter. In particular, torque ripple is reduced when transitioning between two different operating modes of a soft starter. A soft starter may include a first operating mode, designed for improved performance during low-speed operation of a motor, and a second operating mode, designed for improved performance during high-speed operation of the motor. However, transitioning between two different operating modes may result in significant transient currents in the motor, which, in turn, produce torque in the motor. The system described herein reduces this transient torque production in the motor.

Abstract: A device for improving efficiency of an induction motor soft-starts the motor by applying a power to the motor that is substantially less than the rated power of the motor then gradually increasing the power 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 phase angle between the voltage and the current to the motor is measured and power to the motor is increasing when the phase angle is less than a minimum phase angle (determined during soft-start) and power to the motor is decreased 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: When instructed to switch control modes between overmodulation PWM control and sinusoidal wave PWM control, control device corrects the amplitude of a voltage command signal based on a state of power conversion operation performed by an inverter, so as to suppress a change in an influence of dead time over a voltage applied to an alternating-current motor upon switching the control modes. The state of the power conversion operation performed by the inverter includes at least one of a present value of a carrier frequency in a control mode currently employed, an estimated value of the carrier frequency to be obtained when switching the control modes, the length of the dead time, a power factor of alternating-current power exchanged between the inverter and the alternating-current motor, and a driving state of the alternating-current motor.

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: An apparatus for controlling an electric motor is provided. A plurality of switches is provided for controlling a direction of current through motor coils of the electric motor. A brushless motor control circuit is connected to each of the plurality of switches. Responsive to a request to adjust one of an angular velocity and an angular acceleration of the electric motor, the plurality of switches are activated to place the motor coils in a predetermined configuration to maximize torque or reduce a total back electromotive force (BEMF) from the motor coils.

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 electric machine including a housing and a stator arranged within the housing. The stator includes a plurality of stator windings that define a number of phases. A switch module is mounted at the housing. The switch module includes a plurality of switch members that are operatively connected to the plurality of stator windings. The plurality of switch members are configured and disposed to selectively establish one of a first electrical connection configuration and a second electrical connection configuration of the plurality of stator windings.

Abstract: A method and an arrangement are disclosed for identifying one or more parameters of an induction machine when the induction machine is connected to the output phases of a voltage source inverter and the induction machine is in standstill state. The method can include a first phase for magnetizing the machine by providing a first DC magnetization current until the induction machine reaches steady state, the current reference of the inverter having a first value (idc—ref1). A first maximum value (imz—max) of the stator current (isd) is measured during a zero voltage vector. In a second phase, the machine is magnetized by providing a second DC magnetization current, the current reference having a second value (idc—ref2) which is higher than the first reference (idc—ref1). A second maximum value of (isdz—max) the stator current is measured during a zero voltage vector, and a parameter of the induction machine is estimated when the measured first and second maximum values are equal.

Abstract: A digital PWM demodulator includes a first set of delay cells to receive a PWM signal and to propagate the PWM signal in a forward direction for a first interval. Delayed signals obtained at the end of the first interval are propagated in the reverse direction through the delay cells for a second interval. A logic zero feeds into the last cell at the start of the second interval. The output of a last cell in the delay cells at the end of the second interval is indicative of a data value modulated on the PWM signal. The digital PWM demodulator includes a second set of delay cells designed to operate identical to the first set of delay cells. The first set of delay cells and the second set of delay cells in conjunction with additional digital circuitry demodulate alternate periods of the PWM signal.

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: A motor drive controller includes a position detector that detects and outputs positional signals representing rotational positions of the magnetic rotor at first resolution, a position change detector that detects and outputs position change signals representing rotational positions of the magnetic rotor at second resolution higher than the first resolution, a phase synchronizing circuit that generates and outputs low resolution absolute phase information based on the positional and position change signals. The phase synchronizing circuit generates and outputs high-resolution absolute phase information based on the position change signals. A drive voltage signal outputting device outputs a drive voltage signal causing the current to flow through the coils in accordance with the absolute phase information.

Abstract: A controller (100) for controlling a salient-pole machine (200) is disclosed. The controller (100) is adapted to determine at least one operational parameter of the salient-pole machine (200), such as for example a rotor position, a rotor angle or a steady-state voltage. The controller (100) comprises a calculating unit for calculating test pulse properties for test pulses for supply to phase inputs of the salient-pole machine. The test pulse properties thereby comprise a pulse width and the calculating unit (110) is adapted for determining the pulse width in an adaptive manner.

Abstract: A method for controlling an induction machine having a rotor includes the steps of obtaining a torque command, calculating an estimated squared value of resistance of the rotor using the torque command, determining an offset for the resistance of the rotor, and generating an updated measure of rotor resistance using the estimated squared value and the offset.

Abstract: A system and process includes continuously determining an applied armature voltage supplied to a polyphase synchronous machine for which a maximum mechanical load is characterized by a pull-out torque. The armature voltage is supplied from a power source via one of many taps of a regulating transformer. The armature voltage being supplied from the power source to the machine is changed by selecting one of the voltage levels from the taps of the regulating transformer. The tap voltage levels are selected based on the determined applied armature voltage to minimize power consumption of the machine while ensuring based on a predetermined confidence level that the pull-out torque of the machine will not be exceeded.

Abstract: A control circuit for a single-phase AC motor of a dryer, including at least an electronic starting circuit including at least a starting control unit, a first drive circuit, and a bidirectional triode thyristor, a second drive circuit, and a mechanical switch K. The bidirectional triode thyristor is serially connected to a starting winding and a starting capacitor of the motor, and connected to an AC input. The starting control unit is connected to a control end of the bidirectional triode thyristor via the first drive circuit. The mechanical switch K is serially connected to an electrical heating wire, and is connected to the AC input. The starting control unit is connected to a control end of the mechanical switch K via the second drive circuit. The first drive circuit and the second drive circuit are interlocked with each other.

Abstract: Systems and methods are provided for an automotive drive system using an absolute position sensor for field-oriented control of an induction motor. An automotive drive system comprises an induction motor having a rotor, and a position sensor coupled to the induction motor. The position sensor is configured to sense an absolute angular position of the rotor. A processor may be coupled to the position sensor and configured to determine a relative angular position of the rotor based on a difference between the absolute angular position and an initial angular position obtained when the induction motor is started. A controller may be coupled to the induction motor and the processor and configured to provide field-oriented control of the induction motor based on the relative angular position of the rotor.

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 magnetic-pole-position estimating apparatus includes a command voltage output device and a current detector. A model-current calculator is configured to calculate a model current corresponding to a voltage equation for a predetermined model of a motor based on a command voltage and an actual current. A current-difference calculator is configured to calculate a current difference between the model current and the actual current. Each of first and second magnetic-pole-position-difference calculators is configured to calculate a magnetic-pole-position difference between an actual magnetic-pole position of the motor and an estimated or designated magnetic-pole position based on the current difference depending on whether or not a rotation speed of the motor is lower than a predetermined value.

Abstract: A motor start circuit for an induction motor includes a start switch device serving the purpose of interrupting the current or voltage flow through the start winding after the start of the motor. The motor includes a main winding and a start winding, which are supplied with alternating current or voltage from a mains power supply.

Abstract: A device for controlling an alternating-current motor includes a resolver for detecting a rotational position of an alternating-current motor; and a rectangular wave voltage control unit for performing control based on an output of the resolver to provide a rectangular wave voltage to each phase of the alternating-current motor. The control unit causes an amount of change ?? in a voltage phase of the rectangular wave voltage of each phase from a switching reference phase of each phase to increase or decrease equally for each switching in one cycle of an electrical angle determined based on the output of the resolver. In this way, a device for controlling an alternating-current motor is provided to restrain occurrence of an offset current upon rectangular wave voltage control.

Abstract: In various embodiments, the present disclosure provides a speed control system for a motor that includes a fixed speed control portion and a variable speed control portion. The fixed speed control portion is operable to control a speed of a motor in a fixed speed mode wherein the motor is operated at a preselected fixed speed below a predetermined fixed speed mode threshold speed. The variable speed control portion is operable to control the motor in a variable speed mode wherein the motor is operated such that a speed of the motor can be selectively varied within a range between the fixed speed mode threshold speed and a maximum motor speed. The system additionally includes a switching device structured and operable to selectively switch the speed control system between the fixed speed mode and the variable speed mode.

Abstract: Methods and devices are presented herein for estimating induction motor inductance parameters based on instantaneous reactive power. The induction motor inductance parameters, e.g., the stator inductance and the total leakage factor, can be estimated from motor nameplate data and instantaneous reactive power without involving speed sensors or electronic injection circuits.

Abstract: A method for operating a synchronous motor wherein a magnetic field is generated by a first motor component in a predetermined orientation, the method including generating a relative movement between the first and a second motor component limited to a predetermined value, and determining a direction of the relative movement, wherein the generating and determining are repeated until a change in the direction of the relative movement occurs, wherein a magnetic field having a changed orientation with regard to a previously generated magnetic field is generated by the first motor component, and wherein the orientation of the magnetic field with the changed orientation is changed by a predetermined orientation section and depending on the determined direction of the relative movement. The invention encompasses an amplifier for operating a synchronous motor and a system including an amplifier and a synchronous motor.

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 of detecting a phase winding fault in a multi-phase electric machine is executable via a motor controller, and includes measuring feedback signals of the machine, including each phase current, and generating reference phase voltages for each phase. The method includes calculating a predetermined voltage value using the feedback signals and reference phase voltages, and comparing the voltage value to a corresponding threshold to determine the fault. A control action is executed when the voltage value exceeds the corresponding threshold. The voltage value is one or more of: a ratio of a normalized negative sequence voltage to a modulation index, an RMS voltage for each phase, and total harmonic distortion of each phase current. An apparatus detects the fault, and includes a motor controller and an algorithm as set forth above. The apparatus may include a voltage inverter for generating a multi-phase alternating current output for powering the machine.