Abstract: An apparatus for detecting a position of a rotor of a DC motor with N phases having a plurality of windings. The apparatus includes circuitry to couple at least two of the windings between a supply voltage and a reference voltage according to a first current path and allow the current stored in the two windings to be discharged through a second current path. The circuitry is configured to force the at least two windings at a short circuit condition in the second current path. The apparatus also includes a measurement circuit configured to measure the time period of discharging the current stored in the two windings and a rotor position detector for detecting the rotor position based on the measured time period.

Abstract: A method for determining a direction of rotation for an electronically commutated motor (ECM) is described. The motor is configured to rotate a blower and the method comprises rotating the blower using the ECM and determining if the resulting blower rotation is indicative of the desired direction of rotation for the blower.

Abstract: The invention discloses a driving method for single-phase DC brushless motor using sensor only in start-up, comprising: power-up to activate a motor control circuit of a motor; confirming whether the motor is in a rotating state before activation of an excitation? If not, executing a static start-up procedure of using a sensor to detect magnetic poles of the rotor; calculating slope of the BEMF signal to determine the rotation direction of the motor; determining whether the rotation direction of the motor conforming to a predetermined direction; if yes, executing a normal driving procedure; otherwise, executing the static start-up procedure of using a sensor to detect magnetic poles of the rotor. The invention utilizes the present invention utilizes an asymmetric magnetic field caused by a mechanism between a rotor and a stator of a motor to induce a back electromotive force signal and a sensor detection to control rotation direction.

Abstract: Implementations of methods for sensing rotor positions of a motor may include coupling a controller with a PMSM and applying, using the controller, a plurality of vectors to the PMSM, the plurality of vectors including a plurality of dummy vectors and a plurality of measured vectors, wherein at least one measured vector is applied quadrature to a dummy vector from the plurality of dummy vectors immediately preceding each measured vector. The method may also include measuring, with a measurement circuit, a plurality of values from a three-phase inverter coupled with the PMSM, each value of the plurality of values corresponding with one of the plurality of measured vectors, and calculating, with one or more logic elements coupled with the PMSM, based on the plurality of values and using one or more position algorithms, a position of a rotor of the PMSM relative to a stator of the PMSM.

Abstract: Techniques are disclosed for facilitating control of electric motors. A system includes a brushless direct current (BLDC) electric motor that includes a rotor and windings, where the rotor is configured to rotate with an adjustable angular speed. The system further includes a plurality of switching regulators. Each switching regulator is configured to generate an electrical drive signal based on to a torque control signal, where the angular speed of the rotor is based on the electrical drive signals. The system further includes a commutation logic circuit configured to selectively provide the electrical drive signals of the switching regulators to the windings based on a position of the rotor. To selectively provide the electrical drive signals, the commutation logic circuit may be configured to provide routing control signals provided as six-step commutation signals or motor phase control signals provided as sinusoidal commutation signals. Related systems, devices, and methods are also disclosed.

Abstract: An electric motor includes a stator, a rotor provided to be rotatable with respect to the stator, and a driving circuit board including a power IC applying a driving voltage to the stator, a Hall IC detecting a rotation position of the rotor, and a control IC adjusting a phase of the driving voltage in accordance with a magnetic-pole-position signal from the Hall IC and rotation speed information calculated on the basis of the magnetic-pole-position signal. The Hall IC is provided at a position at which an advance angle is larger than zero when a rotation speed of the rotor is zero.

Abstract: A motor driving controller, comprising a rotary position detection device generating a position detection signal corresponding to a rotary position of a rotor of a motor; a control circuit selecting a first driving control signal for performing rectangular wave driving or a second driving control signal for performing driving with an overlapped energization period longer than an overlapped energization period in the rectangular wave driving, based on the position detection signal, thereby to output a driving control signal; and a motor driver outputting a driving signal to a stator coil of the motor based on the driving control signal, wherein the control circuit outputs the first driving control signal at time of starting, and the control circuit outputs the second driving control signal when a rotary state is detected on the basis of the position detection signal.

Abstract: An electrical motor system and a method for operating the electrical motor system are disclosed. The electrical motor system comprises a direct current (DC) source, a filter connected in parallel with the DC source and an electric motor with at least two sets of windings. A voltage signal is provided from the DC source to the inverter circuit where the signal is modulated. The modulated signal is then supplied from the inverter circuit to each set of windings with a respective time offset between each set of windings respectively, providing a very efficient DC bus ripple reduction. Hereby, it is e.g. possible to use small filter capacitors/capacitor banks in electrical motor systems.

Abstract: A control apparatus includes a first determination section determining whether a power-supply voltage has decreased below a first threshold value, an interruption section interrupting a current flow to an inverter if the voltage has decreased below the first threshold value, a second determination section that determining whether the power-supply voltage has increased above a second threshold value, an interruption releasing section releasing the interruption based on the fact that the voltage has increased above the second threshold value, a count section counting the number of interruptions, a limiting section determining whether the decrease in the power-supply voltage is caused by a first factor of an electric rotating machine or a second factor, and limits the counting if the decrease in the power-supply voltage is caused by the second factor, and a third determination section determining whether the interruption is allowed to be released based on the number of interruptions.

Abstract: In one embodiment, a generator includes a rotor configured to rotate in cooperation with a stator to generate electrical power. An exciter of the generator includes at least one circuit board, a stationary exciter stator, and a control circuit. The circuit board is mechanically coupled to a rotor of the generator and includes at least one coil of an electrical conductor. The stationary exciter stator is configured to induce a current in the at least one coil of the at least one circuit board. The control circuit is configured to modify the current from the at least one coil and provide the modified current to a field of the generator.

Abstract: A three-phase switched reluctance motor torque ripple three-level suppression method. A first set of torque thresholds (th1low, th1zero, th1up) is set in rotor position interval [0°, ?r/3]. A second set of torque thresholds (th2low, th2zero, th2up) is set in rotor position interval [?r/3, ?r/2]. Power is supplied to adjacent phase A and phase B for excitation. The power supplied for excitation to phase A leads the power supplied for excitation to phase B by ?r/3. At this moment, phase A is turned off, phase B is turned on and three-level suppression of torque ripple of three-phase switched reluctance motor is realized by dividing the commutation process from phase A to phase B into two sections.

Abstract: An operating method of a synchronous machine is provided, the operating method including: generating an MTPA (Maximum Torque Per Ampere) curve, based on a current limiting circle depending on a rated current of an inverter or a motor and a torque curve depending on a torque command; generating a voltage limiting ellipse, based on a DC-link voltage; displaying, on an X-Y plane, the current limiting circle, the torque curve, the MTPA curve, and the voltage limiting ellipse; and computing a d-axis current and a q-axis current, based on an intersection point between at least two of the current limiting circle, the torque curve, the MTPA curve, and the voltage limiting ellipse, displayed on the X-Y plane.

Abstract: A motor drive controller includes: a motor drive unit; and a lock energization control circuit configured to control the motor drive unit to cause a lock current for holding the rotor at a predetermined lock position to flow from the motor drive unit to the drive coils for lock energization duration before rotation of the motor is started. The lock energization control circuit includes: a first lock energization unit that controls the motor drive unit such that a magnitude of the lock current becomes a first predetermined value when first predetermined duration has elapsed after the lock energization duration is started; and a second lock energization unit that controls the motor drive unit such that the magnitude of the lock current becomes a second predetermined value smaller than the first predetermined value when the lock energization duration is terminated after the first predetermined duration has elapsed.

Abstract: A motor controller that controls a motor in a first control method based on a first current command value and a second control method based on a second current command value. The motor controller includes an analog-to-digital converter to generate the second current command value based on a reference signal externally input to the motor controller and a current limit generator to generate an upper limit value of the first current command value based on the second current command value.

Abstract: An apparatus for controlling an inverter is disclosed. The apparatus for controlling the inverter contained in an inverter system configured to drive a motor determines a slip frequency to be used for compensation of a frequency of a first reference voltage, not only using a first reference voltage (including an amplitude and frequency) of the first reference voltage applied to the inverter, but also using an output current of the motor or a rotor speed of the motor. The apparatus determines not only a frequency of a second reference voltage obtained by compensation of the slip frequency, but also an amplitude of the second reference voltage corresponding to the frequency of the second reference voltage.

Abstract: An inductor motor includes a rotor with teeth and no windings and a stator including teeth, three phase windings, and at least one field winding. A three phase rectifier has an input connected to the phase windings and an output connected to the field winding.

Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; and estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.

Abstract: A motor drive circuit including a back electromotive force detecting module and a processing module is disclosed herein. The back electromotive force detecting module is electrically connected to a single phase DC motor and is configured to detect a back electromotive force of the single phase DC motor and to output a detecting signal correspondingly. The processing module is electrically connected to the back electromotive force detecting module and the single phase DC motor. The processing module is configured to determine the rotation direction of the single phase DC motor according to the detecting signal and a hall signal outputted by a hall element located in the single phase DC motor, and is configured to control the single phase DC motor.

Abstract: A single phase motor drive circuit for driving a single phase motor, comprising: a timer unit for receiving a sensor signal indicative of an angular position of a rotor, and for providing a timing signal in phase with the sensor signal; a waveform generator for generating a waveform for energizing the motor, the waveform generator being adapted for receiving the timing signal and a configurable setting, and for generating the waveform based thereon; a configuration unit for receiving an input signal indicative of a desired motor speed, the configuration unit being adapted for generating the configurable setting as a function of the input signal, and for providing the setting to the waveform generator to dynamically configure the waveform generator. A method, an assembly and a cooling system includes the single phase motor driver circuit.

Abstract: An electric drive system of an electrified vehicle has a power converter with phase leg switching devices controlled by pulse-width modulation to supply multi-phase AC to an electric traction motor. Dead-time intervals are inserted into gate drive signals for the switching devices without introducing any significant distortion in the output of the converter. A direction of current flow between a phase leg and the motor is detected. When the current direction is positive, lower gate signals for a lower switching device in the phase leg have a delayed rising edge and an advanced falling edge while upper gate signals are unmodified. When the current direction is negative, upper gate signals for an upper switching device in the phase leg have a delayed rising edge and an advanced falling edge while lower gate signals are unmodified.

Abstract: A method of normalizing phase measurements for a motor using a normalizing phase measurements (NPM) algorithm that a processor implements to cause a motor controller coupled to stator terminals of the phases to execute forcing a set of input current or voltage vectors (set of input vectors) including repeating the forcing after rotating the rotor through a full mechanical cycle to generate resulting current or voltage samples (resulting samples) of non-normalized phase A and phase B waveforms. The magnitude of the input vectors are sufficiently small to not move the rotor. A maximum value (x_max) and a minimum value (x_min) are determined for each of the non-normalized phase A and phase B waveforms. An offset value and normalization scale factor (NSF) are determined from the max and min values. The offsets and NSFs are applied to the non-normalized phase waveforms to generate normalized phase A and phase B waveforms.

Abstract: In one embodiment, a control circuit for a linear vibration motor may be configured to drive the linear vibration motor to vibrate using a closed loop run mode or an open loop run mode, and may be configured to control the linear vibration motor to stop vibrating using an anti-drive signal wherein the frequency is adjusted to be near to an estimated value of the natural frequency of the linear vibration motor.

Abstract: A three-phase switched reluctance motor torque ripple two-level suppression method. A first set of torque thresholds at rotor position interval [0°, ?r/3]. A second set of torque thresholds at rotor position interval [?r/3, ?r/2]. Power is supplied for excitation. The power supplied for excitation to phase A leads the power supplied for excitation to phase B by ?r/3. Phase A is turned off, while phase B is turned on. An entire commutation process from phase A to phase B is divided. In rotor position interval [0°, ?1], phase A uses the second set of torque thresholds while phase B uses the first set. Critical position ?1 automatically appears in the commutation process. Total torque is controlled. In rotor position interval [?1, ?r/3], phase A uses the second set of torque thresholds, phase B uses the first set, and the total torque is controlled, suppressing torque ripples of a three-phase switched reluctance motor.

Abstract: Systems and methods are provided that may be implemented to provide a power supply with automatic overcurrent protection (OCP) point calibration and/or current sense resistor (Rsense) verification. The provided systems and methods may implement auto-calibration techniques on the secondary side of a power supply to achieve a more precise OCP point than is possible with conventional adapter technology, and in one example may implement auto trimming for OCP voltage threshold value.

Abstract: A motor driving apparatus including a motor including a stator and a rotor rotating in the stator, an inverter configured to supply a driving voltage to a stator coil wound on the stator so as to rotate the rotor, and a control unit configured to, when a target command value is received, change a predetermined reference start-up time point to a start-up time point corresponding to an electrical angle position of the rotor in correspondence with the target command value per rotation of the rotor and to control the inverter to supply the driving voltage at the start-up time point.

Abstract: Implementations of a system for sensing rotor position of a PMSM may include: a controller which may be coupled with the PMSM. The controller may be configured to apply a plurality of voltage vectors to the PMSM to generate a plurality of sensing signals from a stator of the PMSM in response. A comparator may be coupled to the PMSM configured to receive and to compare each one of the plurality of sensing signals with a threshold voltage. A rise time measurement circuit may calculate a plurality of rise times using the plurality of sensing signals in response to receiving a signal from the comparator. The rotor-angle estimation circuit may be configured to identify from the plurality of rise times a shortest rise time and a voltage vector corresponding with the shortest rise time and thereby identify the position of the rotor of the PMSM.

Abstract: A method of synchronizing a synchronous reluctance electric machine wherein the machine has no speed and/or residual magnetization voltage sensor and includes power terminals and rotating masses whose mechanical rotation frequency is subjected to speed transients caused by power cut-off conditions. The method includes at least one step of applying a control voltage with predetermined amplitude and duration to the terminals after the transients, and one step of detecting the electric current induced by the control voltage, the current induced by the voltage having a harmonic spectrum variable according to the frequency differential between the frequency of the control voltage and the mechanical rotation frequency of the rotating masses, to restore power and synchronous rotation control of the machine.

Abstract: A four-phase switched reluctance motor torque ripple two-level suppression method in which power is supplied to adjacent phase A and phase B for excitation. The power supplied for excitation to phase A leads the power supplied for excitation to phase B by ?r/4. An entire commutation process from phase A to phase B is divided into two intervals, phase A which uses the second set of torque thresholds while phase B uses the first set of torque thresholds. Critical position ?1 automatically appears in the commutation process, thus obviating the need for additional calculations. Total torque is controlled between [Te+th2low and Te+th2up]. In rotor position interval [?1, ?r/4], phase A continues to use the second set of torque thresholds, phase B continues to use the first set of torque thresholds, and the total torque is controlled between [Te+th1low and Te+th1up].

Abstract: In accordance with an embodiment, a method for driving a motor includes determining a position of a first pole of a rotor of the motor relative to a position of a Hall sensor. A drive signal is generated in response to the position of the first pole of the rotor of the motor, the drive signal having a duty in accordance with the duty control signal or a second duty control signal. In accordance with another embodiment, a drive circuit for a motor includes a state controller connected to a rotational state generation unit, a pulse width modulation detection circuit, and a duty control controller. An align duty set circuit is connected to the duty control controller.

Abstract: The invention relates to a power supply system of an electric motor (1) comprising a power circuit (3), the input terminals of which are connected to a DC voltage source, and an electronic circuit (4) for controlling the electric motor (1) based on a control signal representative of the set speed of the motor. According to the invention, the system comprises a means (6) capable of reducing the DC voltage value received by the power circuit (3) during the starting of the electric motor (1) and/or during operating phases in which the set speed of the electric motor (1) is below a threshold speed.

Abstract: An integrated circuit for controlling operation of a motor of a fan assembly. The fan assembly includes a housing and a fan. The motor is in the housing. The housing is void of sensors. The motor is configured to rotate the fan. The integrated circuit includes a detection module and a first control module. The detection module is separate from the fan assembly. The detection module is configured to detect a voltage induced in a first coil of the motor or a back electromotive force received from the first coil of the motor. The first control module is configured to receive a control signal from a second control module and control the operation of the fan based on (a) the control signal, and (b) the voltage induced in the first coil of the motor or the back electromotive force. The second control module is separate from the integrated circuit.

Abstract: A motor controller for use in a motor system includes a mode select circuit, a fault detection circuit, a protection logic circuit, and a motor control circuit. The mode select circuit sets the motor controller in one of an internal protection mode and an external protection mode. The fault detection circuit detects whether the motor system is operating in a normal operation state or a fault state. If the motor system is operating in the fault state, the protection logic circuit outputs a protection signal in the internal protection mode, and keeps the protection signal inactive while activating an external diagnostic signal in the external protection mode. The motor control circuit controls a motor of the motor system in response to a speed control signal when the protection signal is inactive, and in response to the protection signal when the protection signal is active.

Abstract: One exemplary embodiment is method of operating an electrically excited synchronous machine (EESM) system. The system includes a converter operatively coupled with one or more stator windings, an exciter operatively coupled with one or more field windings, a controller operatively coupled with the converter and the exciter, and a power supply operatively coupled with the converter and the exciter. The controller determines whether a power supply fault condition exists and whether EESM system is operating in a motor mode or a generator mode. If the power supply fault condition exists and the EESM system is operating in the motor mode, entering one of a motor ride through control mode and a motor controlled braking control mode If the power supply fault condition exists and the EESM system is operating in the generator mode, entering one of a generator ride through control mode and a generator controlled braking control mode.

Abstract: A motor control device according to the present invention is a device for controlling a motor driving an air blower. The motor control device includes: an air flow rate calculator configured to calculate an air flow rate supplied by the air blower; and a torque command generator configured to multiply a motor torque by a square of a ratio of a target air flow rate to the air flow rate or multiply a previously outputted torque command by the square of the ratio of the target air flow rate to the air flow rate, and generate a result of the multiplication as a torque command.

Abstract: A method for operating a brushless, rotating electrical machine, including at least three phase windings, each of which has a first phase winding terminal and a second phase winding terminal. The phase windings are connected to each other, in particular the particular second phase winding terminals are connected to a shared star point, and phase-width-modulated voltage signals being applied separately to each individual phase winding, and at least one selected phase winding being at least temporarily connected to a constant electrical potential. To minimize switching operations and to reduce the alternating current component of the current source, the pulses of the pulse-width-modulated signals applied to the remaining phase windings are at least temporarily phase-shifted with respect to each other during the period in which the selected phase winding is connected to a constant electrical potential.

Abstract: A motor control device capable of executing a start mode that takes into consideration both the start performance with respect to a residual load and the life of a drive circuit is provided. A motor control device for executing a start mode in which a rotor is rotated by forced commutation control: stores a current value at the time when a stop command to a synchronous motor is issued; and decides, when a start command to the synchronous motor is issued after the issuance of the stop command, a target current value based on the stored current value in the start mode in response to the start command.

Abstract: A brushless motor includes a rotor, a plurality of sets of stator windings, a position detection assembly, a MOSFET assembly, an inductance detection module and a main control module that controls them. The position detection assembly has a plurality of detection elements for detecting a position of the rotor and a position detection module for receiving signals fed back from the detection elements with the position detection module being electrically connected to the main control module and feeding back the positional information of the rotor thereto. The main control module alternatively switches between the position detection assembly and the inductance detection module to detect the position of the rotor.

Abstract: A motor drive device drives a multi-phase synchronous motor in an electric compressor. The multi-phase synchronous motor includes a rotor that is provided with a permanent magnet and a stator having coils of different phases. The motor drive device includes an inverter that supplies current to the coils and a control unit that controls the inverter. The control unit executes an initial angular position calculation processing of detecting a d-axis and a q-axis as an initial angular position of the rotor, a rotating processing of rotating the d-axis and the q-axis in a direction opposite to rotation of the rotor, an acceleration processing of accelerating the rotation of the rotor, and a sensorless control processing of controlling the rotation of the rotor.

Abstract: The purpose of the present invention is to reduce noise by controlling vibration due to rotation fluctuation, and to consume only current required for maintaining the rotation by bringing the current for driving a motor closer to a state of synchronization. A drive means drives a sensorless brushless DC motor by switching an energization pattern at a constant frequency to determine the rotation position of the rotor of the sensorless brushless DC motor. A detection means detects a zero-cross signal representing the switching of the phase of the rotor. A calculation means calculates a synchronization determination rate representing a percentage of the number of detected zero-cross signals. A pulse width control means controls the pulse width of a PWM drive duty in the drive means so that the calculated synchronization determination rate falls within a target range.

Abstract: Circuits and methods for driving ERM motors are disclosed herein. An embodiment of the circuit includes an input, wherein an input signal is receivable at the input and a back EMF signal. The circuit operates in a closed loop mode when the back EMF signal is less than a lower threshold value and the difference between the value of the input signal and the back EMF signal indicates that the velocity of the motor needs to increase. The circuit operates in an open loop mode when the back EMF signal is greater than a high threshold value and the difference between the value of the input signal and the back EMF signal indicates that the velocity of the motor needs to increase.

Abstract: The present invention is intended to reduce noise and vibration of a motor. A first duty correction circuit generates a first corrected duty instruction value which changes with an increment same as an increment of a duty instruction value and in which an offset value as a constant is reflected. A second duty correction circuit generates a second corrected duty instruction value which changes with an increment different from an increment of the duty instruction value. A selector outputs, as the corrected duty instruction value, either one of the first corrected duty instruction value and the second corrected duty instruction value in accordance with a magnitude relation between the duty instruction value and a duty reference value.

Abstract: A method for determining a reserve torque in an electronically-switched drive mechanism, specifically a pulse motor for a headlamp beam adjustment system, based upon a parameter in an essentially linear relationship to a back electromotive force of the drive mechanism. Whereby, for the determination of the back electromotive force-related parameter, the variation in the drive current is determined in relation to a change interval.

Abstract: An isolated power management system includes at least one electronic power generator with a stationary side and a rotational side. The stationary side has an exciter field stator winding, a main field stator winding, and an isolator stator winding. The rotational side rotates with respect to the stationary side and includes a rotor power converting unit. At least one digital engine microcontroller generates a first electrical excitation current and excites the exciter field stator winding to generate a first electromagnetic field. The rotor power converting unit generates a second electromagnetic field in response to being energized by the first electromagnetic field. The main field stator winding and the isolator stator winding output first and second power signals, respectively, in response to being energized by the second electromagnetic field, where the second power signal is independent and isolated from the first power signal.

Abstract: A method for determining the position of the rotor of an electric machine having multiple phases in relation to the stator. The change ?? in the time derivative ? of the current I flowing through at least one of the power inputs is determined. The change ?? is caused by a change ?U in the potential U on at least one of the power inputs of the electric machine. A measurement signal that is representative of a position of the rotor is determined from multiple simultaneously or successively determined changes ??.

Abstract: A motor drive control device uses a rotor position sensorless control scheme to drive a motor. The motor drive control device includes a rotational speed deriving component, a startup component and a changing component. The rotational speed deriving component derives rotational speed of the motor just before startup of the motor. The startup component starts up the motor by outputting to the motor a drive signal based on at least one of a direct-current excitation scheme that fixes the rotor position in a predetermined position by performing direct-current energization, and a forced drive scheme that accelerates the motor to a predetermined rotational speed by performing forced energization that applies a predetermined voltage and frequency. The changing component changes the drive signal based on at least one of the direct-current excitation scheme and the forced drive scheme in accordance with the rotational speed of the motor derived.

Abstract: A method of controlling a brushless permanent-magnet motor. The method includes commutating a winding of the motor at times that are retarded relative to zero-crossings of back EMF in the winding.

Abstract: Various embodiments of an electric motor and electronic control for an electric motor are disclosed. An exemplary electric motor comprises a single-phase brushless permanent magnet electric motor. In exemplary embodiments, the electronic motor control is configured to commutate an electric motor at a frequency other than line frequency, perform pulse width modulation, and drive the electric motor with a drive waveform that approximates the counter-electromotive force of the motor.

Abstract: A cordless electric power tool comprises a motor that drives a tool, a battery that supply electric power to the motor and a motor drive circuit that is disposed between the motor and the battery. The motor is a three-phase brushless motor, and the battery has a nominal voltage of 18 volts. An overall electric efficiency of the cordless electric power tool becomes at least 70 percent when a value of current passing through the motor becomes at least 35 amperes but no more than 45 amperes and the cordless electric power tool outputs power of at least 450 watts but no more than 550 watts.

Abstract: A mobile working machine includes an energy source, a storage circuit for storing electrical energy, a first electronic power converter stage between the storage circuit and the energy source, an electrical machine for driving actuators, a second electronic power converter stage between the storage circuit and the electrical machine, and a control system for controlling the first electronic power converter stage responsive to the power taken by the second electronic power converter stage from the storage circuit, the control system providing a control signal path from the storage circuit to the first electronic power converter stage. The signal processing properties of the control signal path are dependent on the electrical energy stored by the storage circuit in order to allow the electrical energy to vary, but within desired limits, so as to reduce the peak power taken from the energy source.

Abstract: A position sensorless step-wise freewheeling control method for a switched reluctance motor having dual switched-mode power converters for each phase doesn't require any additional external hardware, any rotor-position sensor, or storage of flux linkage data of the motor. After the upper and lower tubes of the main switch are switched off, and the phase of the switched reluctance motor enters into a negative voltage forced freewheeling state, the phase current is detected. When the phase current falls to a preset threshold, one of the upper or lower tubes is switched on and the phase enters into a zero voltage natural freewheeling state. When the phase current reaches a peak value, the rotor position becomes the start position of the minimum phase inductance and the rotor position is used as the switch-on position of the main switch. The upper and lower tubes are then switched on.