Abstract: A motor drive device is provided which allows control to be performed depending on a position of magnetic poles of a rotor even when a motor rotor angle sensor malfunctions. The device controls a motor for driving a wheel of an electric vehicle, depending on the position of the magnetic poles by using an angle sensed by the angle sensor provided at the motor. The device includes an estimator estimating an angle of a rotor of the motor without using a rotation sensor; a sensor malfunction determiner determining a malfunction of the angle sensor; and a switcher causing control to be performed using a angle estimated by the estimator instead of the angle sensed by the angle sensor once the determiner determines that the angle sensor malfunctions.

Abstract: A system and method for determining the start position of a motor. According to an embodiment, a voltage pulse signal may be generated across a pair of windings in a motor. A current response signal will be generated and based upon the position of the motor, the response signal will be greater in one pulse signal polarity as opposed to an opposite pulse signal polarity. The response signal may be compared for s specific duration of time or until a specific integration threshold has been reached. Further, the response signal may be converted into a digital signal such that a sigma-delta circuit may smooth out glitches more easily. In this manner, the position of the motor may be determined to within 60 electrical degrees during a startup.

Abstract: Disclosed is a current source inverter device which controls the power factor in an arbitrarily configurable manner without a magnetic pole position detector. The device is provided with a current source inverter; a motor supplied with alternating current power from the current source inverter; and a control means which detects the terminal voltage of the motor, calculates the motor's internal induced voltage and the motor current that flows in the motor based on the detected terminal voltage, and controls the current source inverter. The control means calculates the phase difference (?c) between the terminal voltage and the motor current, the phase difference (?x) between the motor current and the internal induced voltage, and the phase difference (?v) between the terminal voltage and the internal induced voltage.

Abstract: To achieve peak acoustic and power performance, the coil or applied current should be in phase or substantially aligned with the back electromotive force (back-EMF) voltage. However, there are generally phase differences between the applied current and back-EMF voltage that are induced by the impedance of the brushless DC motor (which can vary based on conditions, such as temperature and motor speed). Traditionally, compensation for these phase differences was provided manually and on an as-needed basis. Here, however, a system and method are provided that automatically perform a commutation advance by incrementally adjusting a drive signal over successive commutation cycles when the applied current and back-EMF voltage are misaligned.

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: A motor control device includes an inverter circuit including a plurality of switching elements connected into a three-phase bridge configuration and converting a direct current into a three-phase alternate current, a current detecting element connected to a direct current side of the inverter circuit, thereby generating a signal corresponding to a current value, a PWM signal generating unit which determines a rotor position based on phase currents of the motor and generates a three-phase PWM signal pattern so that the signal pattern follows the rotor position, and a current detecting unit detecting phase currents based on the signal generated by the current detecting element and the PWM signal pattern. The PWM signal generating unit generates the three-phase PWM signal pattern so that the current detecting unit is capable of detecting two phase currents in synchronization with advent of two fixed time-points within a carrier period of the PWM signal respectively.

Abstract: An applied-voltage electrical angle setting method for a synchronous motor includes detecting applied voltage and current of the synchronous motor M, calculating current peak value Ip based on the detected values while calculating present applied voltage phase ?, calculating target current phase ?targ based on the current peak value Ip followed by calculating target applied voltage phase ?targ corresponding to the target current phase in a target value setting unit 20, and calculating new applied voltage electrical angle instruction value ?vtarg, based on change angle ??v obtained by correcting a difference between the present applied voltage phase ? and the target applied voltage phase ?targ by response time constant L/R of the synchronous motor, rotational speed ? calculated based on the applied voltage and the current, and the previous applied voltage electrical angle instruction value ?vtarg, in a voltage electrical angle instruction value setting unit 10.

Abstract: Systems and methods for generating a signal useful in the commutation of current through windings of brushless direct current electric motors are provided. Such methods comprises detecting a kickback pulse in a non-driven winding of a motor; detecting a rotor-induced zero crossing in the non-driven winding following the detection of the kickback pulse; and using the detection of the rotor-induced zero crossing to generate a signal useful in commutation of the motor.

Abstract: After a rotor of a three-phase brushless motor is previously moved by a simple control method to a predetermined rotary position, a motor is started-up. A brushless motor control device (10) moves a rotor (3) to a predetermined rotary position (stop position) before a three-phase brushless motor (1) is started-up. Direct current Iuw is flowed between the same phases (U-phase, V-phase) for an initialization time, such as several 10 msec, thereby previously moving the rotor (3) to a predetermined rotary position. At the time when the initialization time elapses, the rotor (3) has moved to the predetermined rotary position. Therefore, the brushless motor control device (10) has recognized which phase is to be conducted first in order to rotate the motor 1 forward/backward. Thus, when the rotor is rotated forward/backward, the brushless motor control device (10) can accurately set a conduction phase to a motor coil.

Abstract: A motor driving system is disclosed having a control device 4A for controlling a synchronous motor 1, the control device 4A comprising a sensorless control algorithm device 20 that includes an abnormality determining device 25 for determining abnormality of the algorithm based on a magnetic pole position error estimated value of the motor 1. When the abnormality determining device 25 has determined abnormality of the algorithm, the control device 4A controls a power converter 2 using a magnetic pole position detected value detected by a magnetic pole position detector 30 attached to the motor, in place of using a magnetic pole position estimated value. This motor driving system can guarantee reliability of the sensorless control algorithm device 20 while assuring safety. Safety of electric vehicles is enhanced by installing the motor driving system that has been guaranteed reliable.

Abstract: The present invention relates to a motor control device provided with the function of detecting the rotor position of a synchronous motor in a sensor-less fashion. The motor control device previously stores a current phase ? defined by the two parameters that are an induced voltage peak value Ep and the subtracted value (?e??i) obtained by subtracting an induced voltage electrical angle ?e from a current electrical angle ?i, and based on the actual detected Ep, ?i, and ?e, selects ? by referring to the ? previously stored, and calculates the rotor position ?m by subtracting the selected ? from the actual detected ?i. Then, in case of selecting ?, the actual detected Ep and ?e are corrected according to changes in the current flowing through the coil. As a result, a detection accuracy for the rotor position during a transition period is enhanced.

Abstract: A motor control apparatus according to the embodiment includes a rotational position estimating unit, a change amount estimating unit, and an inductance estimating unit. The rotational position estimating unit estimates a rotational position of a rotor from a motor parameter including a q-axis inductance of a motor on a basis of an output current to the motor and a voltage reference. The change amount estimating unit estimates a change amount of an output torque with respect to a current phase change of the motor corresponding to a high frequency signal whose frequency is higher than a drive frequency of the motor. The inductance estimating unit estimates an inductance value that obtains a maximum torque on a basis of the change amount as the q-axis inductance.

Abstract: A control system for a motor includes an angle determination module, a control module, an angle generation module, and an estimator module. The angle determination module generates an output rotor angle indicative of a desired angle of a rotor of the motor. The control module controls current supplied to the motor based on the output rotor angle. The angle generation module generates a commanded rotor angle in response to a commanded speed. The estimator module determines an estimated rotor angle of the motor. Upon startup of the motor, the angle determination module generates the output rotor angle based on the commanded rotor angle. Upon beginning of a transition period, the angle determination module generates the output rotor angle based on the commanded rotor angle and the estimated rotor angle. Upon ending of the transition period, the angle determination module generates the output rotor angle based on the estimated rotor angle.

Abstract: An angle estimation control system of a permanent magnet motor is provided. The angle estimation control system includes a Clarke transform module, a Park transform module, and an angle estimation module. The Clarke transform module generates orthogonal current signals in accordance with motor phase currents. The Park transform module generates a current signal in response to the orthogonal current signals and an angle signal. The angle estimation module generates the angle signal in response to the current signal. The angle signal is related to a commutation angle of the permanent magnet motor. The current signal is controlled to be approximately equal to zero. The angle signal is further coupled to generate three phase motor voltage signals.

Abstract: A control method for a sensor-less, brushless, three-phase DC motor. The effects of commutation on the motor may be minimized using a sinusoidal current drive on each electromagnet. The “off” times and/or the “on” times of the drive transistors controlling the electromagnets in a full “H-bridge” configuration drive scheme may be delayed. By overlapping the drive signals to the electromagnets with respect to a commutation command, the effects of switching between electromagnets may be minimized. In addition, the “on” and “off” times may also be adjusted during the overlapping to further ensure that the coils continuously conduct current, and that the current does not change direction during the switching. The delays, and hence the overlap times of the coil drive signals may be dynamically controlled, for example by using digital timers, making the response predictable and easily controlled.

Abstract: The invention relates to an electric device (1) comprising an alternating current electric motor (3) and a control inverter (5) for controlling the phase or phases of the motor (3). The motor (3) comprises, on at least one winding of at least one phase (PA, PB, PC), a point (Ma, Mb, Mc) for measuring a voltage relative to a predefined potential (M), the measurement point (Ma, Mb, Mc) being chosen so that it divides the winding into a first (Za1; Zb1; Zc1) and a second (Za2; Zb2; Zc2) portion such that the electromotive forces (ea1, ea2) induced in the two portions are phase-shifted relative to one another and means (11A; 11B; 11C) for measuring the voltage between the measurement point and the predefined potential. The invention also relates to an associated method for measuring electromotive forces.

Abstract: A vacuum pump having a vacuum pumping mechanism mounted for rotation by a shaft and a brushless motor for rotating the shaft where the vacuum pumping mechanism comprises a turbo pumping mechanism comprising pumping stages, and a molecular drag pumping mechanism comprising at least one pumping stage, and a shaft supported for rotation by bearings, and where the motor comprises a permanent magnet rotor fixed relative to the shaft and the rotor has four poles and a stator has non-overlapping stator coils.

Abstract: A controller outputting voltage instructions for drive control of an electric rotating machine adds, by using adders, position estimation voltage instructions for estimating the rotor position generated by a position estimation voltage generator, to drive voltage instructions, and outputs the resultant signals as voltage instructions. A position estimation device includes current extractors for extracting position estimation currents having the same frequency components as that of the position estimation voltage instructions, from electric rotating machine currents detected by a current detector, a position estimation current amplitude calculation section for calculating position estimation current amplitudes from the position estimation currents; and an estimation position calculation unit for calculating an estimated position of the electric rotating machine, based on the position estimation current amplitudes.

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: An inverter device, a motor driving device, a refrigerating air conditioner, and a power generation system, which can reduce the recovery loss thereof, are obtained. A plurality of arms that can conduct and block current are provided. At least one of the plurality of arms includes: a plurality of switching elements each having a parasitic diode and being connected in series with each other; and a reverse current diode connected in parallel with the plurality of switching elements.

Abstract: A motor control device includes feed-forward control means for detecting a change amount of a predetermined monitoring target, which is used for changing the number of revolutions of a motor without depending on revolution number detecting means, and correcting the number of revolutions recognized by a controller.

Abstract: A control system controls a multiphase rotating machine by a 120° energization process and a PWM process. In the 120° energization process, respective ones of switching elements of a high side arm and switching elements of a low side arm of a power conversion circuit are turned on. In the PWM process, the switching elements of the power conversion circuit turn on/off so that two phases that are connected to the switching elements that are in the on-state are alternately rendered conductive to the high potential side input terminal and the low potential side input terminal of the power conversion circuit.

Abstract: A magnetic pole position detecting device includes a calculating unit for correcting a magnetic pole position detected by a magnetic pole position detecting unit. In this magnetic pole position detecting device, an additional phase is added to the magnetic pole position detected by the magnetic pole position detecting unit, in order to move a rotor. In relation to a movement amount before and after this movement, a movement amount detected by the magnetic pole position detecting unit is compared with a movement amount detected by an encoder. When a difference between them is larger than a predetermined threshold, a process of detecting the magnetic pole position is determined as false detection.

Abstract: A variable gain amplifier includes: a first input terminal, a second input terminal and an output terminal; an operational amplifier; a first resistor interposed between the first input terminal and an inverted input terminal of the operational amplifier; second and third resistors interposed between the inverted input terminal and the output terminal; and a fourth variable resistor having a first terminal connected to a node between the second resistor and the third resistor and a second terminal connected to the non-inverted input terminal, wherein the fourth variable resistor includes a resistance pass including a resistor and a switch.

Abstract: Identification without shaft encoder of electrical equivalent circuit parameters of a three-phase asynchronous motor comprising: -standstill position search of the rotor, so that the d flux axial direction of the rotor is aligned opposite the cc axial direction of the stator; -test signal voltage supply U1d in the d flux axial direction of the motor whereby the q transverse axial direction remains without current; -measuring signal current I1d of the d flux axial direction of the motor; -identification of equivalent circuit parameters of the motor based on the test signal voltage U1d and on the measuring signal current I1d in the d flux axial direction; whereby the rotor remains torque-free. The method used to control electrical drives. An identification apparatus for a synchronous motor and a motor control device comprising the apparatus, whereby identified equivalent circuit parameters can be used to determine, optimize and monitor a motor control.

Abstract: A method for the identification without a shaft encoder of magnetomechanical characteristic quantities, in particular the mass moment of inertia J and the permanent magnetic flux ?PM between rotor and stator of a three-phase synchronous motor, comprising:—constant voltage supply U1d in the d flux axial direction;—test signal voltage supply U1q in the q transverse flux axial direction;—measuring signal current measuring I1q of the q transverse flux axial direction;—identification of magnetomechanical characteristic quantities of the synchronous motor on the basis of the test signal voltage U1q and of the measuring signal current I1q; whereby the rotor can execute deflection movements with pre-definable maximal amplitudes. Method use also for control of electrical drives.

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 system and method are presented for aligning a rotor in a motor. The motor may include the rotor and a plurality of pairs of electromagnets. One or more pairs of electromagnets may be excited at a first excitation level. The one or more pairs of electromagnets may be less than all of the plurality of pairs of electromagnets. The excitation of the one or more pairs of electromagnets may be increased to a second excitation level over a first period of time. The excitation of the one or more pairs of electromagnets may be decreased to a third excitation level over a second period of time. Exciting the one or more pairs of electromagnets, increasing the excitation, and decreasing the excitation may cause the rotor to stop in a known position.

Abstract: A measurement circuit in a motor circuit generates signals for use in a motor control strategy for an electric motor. The measurement circuit comprises a first current sensing means which produces an output signal indicative of the current flowing in a di/dt path connecting the phases of the motor to a ground or a common positive supply voltage, and further comprises a second current sensing means which produces an output signal indicative of the rate of change of current flowing in the ground line, and in which the second current sensing means comprises a Rogowski coil.

Abstract: A method and arrangement for determining the position of the drive mechanism of an electric machine from the current supplied thereto. Determination of the position is effected over two independent channels by measuring the three-phase current of the electric machine or motor, converting the measured values to the current space vector, calculating the angle of the current space vector within one electrical revolution, and determining the position of the motor. A current command, the field of which acts in the direction of the flux or field of the drive mechanism or rotor, is added within the motor stator.

Abstract: Method for control of synchronous electrical motors that enables determining the instantaneous motor load angle and rotor speed without using rotor position sensors. The method is realized with solving the set of differential equations that govern the currents in the stator windings of the motor for the time intervals between each two consecutive crossings of the currents in the windings of their set values and deriving relationships between the induced in the windings back-electromotive force voltages and the parameters of the Pulse Width Modulation. The parameters of the Pulse Width Modulation are measured and stored in a memory and based on the derived relationships the values of the back-electromotive force voltages are calculated continuously in time. From the values of the back-electromotive force voltages the motor load angle and rotor speed are calculated and used as feedback signals for the closed-loop control of the motor.

Abstract: A conventional method used for a startup mode for a brushless direct current (DC) motor employed complementary inductive rise times. Specifically, inductive rise times rise times for a driving state and its complementary state were compared to one another such that when the inductive rise times cross a switching point had been reached. This methodology, however, significantly affects the efficiency of the driving torque and power consumption. Here, however, a derivative of the inductive rise time is employed, which can determine the switching event without the need for a use of a complementary state, improving motor performance.

Abstract: A rotating electromechanical machine has a rotor having at least one current-carrying winding and at least one rotor-mounted sensor configured to sense a machine property or parameter during machine operation. Rotor-mounted circuitry dynamically modifies at least one property of the current-carrying winding during machine operation in response to the sensed machine property or parameter.

Abstract: Various methods of detecting a found rotor, a lost rotor, a locked rotor and a caught rotor after a power disruption using flux estimates are disclosed. Also disclosed are permanent magnet motor controllers and assemblies suitable for performing one or more of these methods.

Abstract: A permanent magnet motor for position sensorless drive operation provides a stator design that exhibits a saliency (machine asymmetric) functionally dependent on rotor position as caused by periodic magnetic saturation of stator structure. This saturation property is caused by rotor zigzag leakage flux from surface permanent magnets. The stator structure may be designed to further saturate from zigzag leakage flux to provide greatest spatial saliency in the quadrature phase for motor position sensorless position estimation. The position, velocity, and shaft torque can be extracted by measuring the phase current from the stator coil of permanent magnet motor.

Abstract: A synchronous-machine starting device includes an induction voltage operating unit calculating an induction voltage induced to an armature of a synchronous machine based on an estimated phase representing a position of a rotor, an estimated rotational speed of a rotor, an AC voltage signal, and an AC current signal, and outputting an induction voltage signal representing the calculated induction voltage, a selection unit selecting and outputting one of the induction voltage signal received from the induction voltage operating unit and the AC voltage signal received from the AC voltage detection unit, and a feedback operating unit outputting a speed signal representing the calculated estimated rotational speed based on calculated phase error to the induction voltage operating unit, and outputting a position signal representing the calculated estimated phase to the electric power conversion control unit and the induction voltage operating unit.

Abstract: At least one example embodiment discloses a drive system including a motor including a rotor, the motor configured to receive a measured current, a controller configured to generate a voltage command for the motor, a sliding mode observer configured to determine an estimated current for the motor based on the voltage command, determine a difference between the measured current and the estimated current, and determine a switching control vector and an estimator configured to estimate a rotor position based on the switching control vector, the switching control vector being determined based on the difference and adaptive parameters of the sliding mode observer, the controller being further configured to control the motor based at least in part on the estimated rotor position.

Abstract: A synchronous machine starting device in which AC power is supplied to an armature of a synchronous machine, the supplied AC voltage is detected to determine a rotor position of the synchronous machine, and the supplied power is controlled based on the detected rotor position. To detect rotor position, a first position signal indicating a timing at which a level of AC voltage supplied to the armature of the synchronous machine reaches a prescribed value is output. An error of an estimated phase is calculated based on the estimated phase indicating the rotor position and the detected AC voltage, and the estimated phase is calculated based on the calculated error to produce a second position signal indicating the calculated estimated phase. A selected of first and second position signals is output to indicate the rotor position of the synchronous machine for control of AC power supplied to the armature.

Abstract: A control system is provided for an AC electric motor which comprises a rotor and a stator and a plurality of phase windings connected in a star formation, each winding having one end connected to a common neutral point and another end arranged to have a terminal voltage applied to it. The control system comprises switching means arranged to control the terminal voltages applied to the windings and control means arranged to control the switching means so as to switch it between a plurality of states in each of a sequence of PWM periods. The control means is further arranged to measure the voltage at the neutral point at sample times within the PWM periods and to generate from the measured voltages an estimation of the rotational position of the rotor.

Abstract: The present invention provides a motor control device including a feedback control system that generates a torque command for reducing a difference between an operation command signal for commanding an operation of a motor and a detection signal of a detector attached to the motor to detect a position and speed of the motor and drives the motor. The motor control device includes a correcting unit configured to estimate an amplitude and a phase of a correction amount for suppressing the detection error included in the detection signal and sequentially update estimation values of the amplitude and the phase and a post-correction-detection-signal calculating unit configured to generate a post-correction detection signal, which is a difference between the detection signal and the correction amount, instead of the detection signal.

Abstract: A sensorless control apparatus of a motor may include: a position estimator configured to compensate for a resistance and a magnetic flux of a permanent magnet of the motor according to a temperature of the motor, and/or configured to generate an estimated speed of a rotor of the motor based on the compensated resistance and the compensated magnetic flux of the permanent magnet; and/or a speed controller configured to generate a command current based on a command speed of the rotor and the estimated speed of the rotor.

Abstract: The present invention provides a simple, robust, and universal position observer for use with sensorless synchronous machines. The observer may be implemented using an equivalent EMF model of a synchronous machine or, alternately, using a sliding mode controller based on the equivalent EMF model of the synchronous machine. The observer may be used on any type of synchronous machine, including salient or non-salient pole machines such as a permanent magnet, interior permanent magnet, wound rotor, or reluctance synchronous machine. The observer provides low sensitivity to parameter variations and disturbances or transient conditions in the machine. In addition, no knowledge of speed is required as an input to the observer and an estimated position may be calculated using a subset of the machine parameters.

Abstract: A motor is driven based on an axis current value in a rotating coordinate system that rotates in accordance with a control angle that is a rotational angle used in a control. The control angle is calculated by adding an addition angle to an immediately preceding value of the control angle in each predetermined calculation cycle. A command steering torque is set based on a predetermined steering angle-torque characteristic. The addition angle is calculated based on the deviation of a detected steering torque from a command steering torque. The addition angle based on the deviation is changed when a predetermined condition is satisfied.

Abstract: The invention relates to a method of controlling the run-up of an electronically commutated electric motor (1) to drive a tool. A rotor (7) rotates in the rotating field (21) of the stator (2). The field windings (3, 4, 5) alternately have a supply voltage applied thereto via an actuation unit (10) in order to obtain an advancing motor rotating field. For advancing the rotating field in the rotational direction (29) of the rotor (7), the inductance of the arrangement of the field coils (3, 4, 5), which is ascertained via a changing measuring current (IM), is evaluated and the advancement is carried out upon reaching a maximum.

Abstract: A surgical motor control device for controlling a surgical drive unit comprises a sensorless electric motor with M motor windings. The motor control device is configured to perform a method for controlling the drive unit. The motor control device be configured to control the drive unit using a multiphase PWM method. An improved method for controlling a surgical drive unit and an improved surgical drive system are also proposed.

Abstract: A motor magnetic pole position correction method includes preventing a movement of a movable element of a direct drive motor by mechanical brake (step S9), generating a command that designates a position spaced or separated from the present position (step S10), detecting a torque command value of the direct drive motor (step S12), determining a magnetic pole position correction value based on a comparison between the detected torque command value and a predetermined threshold value (steps S14 and S16), storing the determined magnetic pole position correction value in a memory (step S18), and performing motor control using an electrical angle offset value obtained based on the magnetic pole position correction value stored in the memory.

Abstract: An electric drive (1) comprises: a permanent magnet brushless motor (2), a motor (2) power supply bridge (3), a circuit for controlling the power supply bridge (3) according to rotor position and phase currents (IS); the drive (1) comprises a circuit (6) for detecting the zero crossings of the induced counter electromotive force (ES) in the stator windings to determine the position of the rotor and a circuit (25) for indirectly detecting the amplitudes of the phase currents (IS).

Abstract: An electric vehicle powertrain includes a battery configured to couple with an external power source, a power plant including at least one three-phase electric motor, and a power controller configured to receive electrical energy from the battery and to controllably provide electrical energy to the at least one electric motor. The electric motor includes a stator having a plurality of electrical windings and a rotor having a magnetic field orientation, with the rotor being configured to rotate relative to the stator. The power controller is configured to warm an engine fluid by determining the position of the rotor relative to the stator; determining a DC current for each of the three motor phases such that the electromagnetic field of the stator mirrors the magnetic field orientation of the rotor; and by providing the determined DC currents to the electric motor to resistively heat the fluid.

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

Abstract: Disclosed herein is a sensorless-type brushless DC motor, including: a magnet provided in a rotor; and a stator formed by winding a coil on a core stacked with sheets while facing the magnet, wherein the position of the rotor is detected by detecting back electromotive force induced to the coil, the back electromotive force includes a harmonic component 5 times higher than a fundamental wave, and an amplitude ratio of the 5-times harmonic wave to the fundamental wave is set to be 1% or more. Further, the sensorless-type brushless DC motor can prevent a failure in detecting an initial position of the rotor by controlling a waveform of the back electromotive force and minimize an increase of a starting time.