Abstract: A method for determining an initial rotor position of a permanent magnet synchronous motor (PMSM) includes: generating a plurality of transient currents by applying a plurality of voltages to each phase stator winding of a three phase stator winding of the PMSM; generating three phase current differences according to the plurality of transient currents; determining a first zone in which the initial rotor position of the PMSM is located according to the three phase current differences, wherein angles between 0-360 degrees are divided into a plurality of zones, and the first zone is selected from the plurality of zones; calculating three line current differences according to the three phase current differences; and determining the initial rotor position of the PMSM according to the first zone and the three line current differences.

Abstract: A motor drive device: a power conversion unit; a current detection unit that detects a phase current of the alternating-current motor; a position/speed specifying unit that specifies a magnetic pole position and a rotational speed of the alternating-current motor; a d-axis current pulsation generating unit that generates a d-axis current pulsation command based on q-axis current pulsation or a q-axis current pulsation command, which being in synchronization with the q-axis current pulsation or the q-axis current pulsation command and preventing or reducing an increase or decrease in amplitude of the voltage command; and a dq-axis current control unit that generates the voltage command for controlling the phase current on the dq rotating coordinates, which rotate in synchronization with the magnetic pole position, by using the magnetic pole position, the rotational speed, the phase current, the q-axis current pulsation or the q-axis current pulsation command, and the d-axis current pulsation command.

Abstract: A method for initial position detection of an electric motor includes determining a delta voltage for each of three pairs of stator windings by sequentially energizing and deenergizing each pair. The delta voltage is measured through a non-energized stator winding connected to a center tap of each respective pair. A minimum delta voltage is determined from an absolute value of a minimum of the three delta voltages. The minimum delta voltage is associated with a remaining stator winding not included in the respective pair. The two delta voltages not associated with the minimum delta voltage are compared to determine the proximity of the remaining stator winding to one of a D-axis of a rotor of the electric motor and a Q-axis of the rotor.

Abstract: According to an aspect, there is provided an apparatus for performing angular position error estimation. The apparatus operates (601) a synchronous motor (111) according to a pre-defined pulsating torque signal using a sensorless vector control method with high-frequency voltage injection. The pre-defined pulsating torque signal has a zero mean and corresponds to a torque operating point. The apparatus measures (602) a first value of an estimated angular position at a first time instance corresponding substantially to an end point of the pre-defined pulsating torque signal and second values of the estimated angular position and an estimated angular speed at a second time instance occurring after the first time instance. Based on the measured values, the apparatus estimates (603) an error in the estimated angular position and stores (604) the error to a lookup table.

Abstract: The invention relates to a method for operating an electronically commutated electric motor (10), in which method, during ongoing operation of the electric motor (10), in order to achieve an optimal operating point of the electric motor (10), a pre-commutation angle (14) provided by a control device (12) is regulated. According to the invention, during an operation of the electric motor (10), a period signal (16) is modulated to the pre-commutation angle (14) and a state parameter (18) of the electric motor (10) correlating with an efficiency of the electric motor (10) is detected.

Abstract: A motor driving control device includes a motor driving unit, a position detection unit, a current detection unit and a control unit. The control unit includes a change detecting means configured to detect a predetermined phase change in the position signal, a first switching means configured to sequentially switch energization patterns of the coils with the plurality of phases based on a timing when the phase change is detected, and a second switching means configured to, in a state where the change detecting means does not detect the phase change, when a value of the drive current becomes a predetermined first threshold or more during a monitoring time period after a timing when the predetermined phase change in the position signal is expected, perform an operation to forcibly switch to a next energization pattern regardless of the timing of switching the energization pattern by the first switching means.

Abstract: The method for detecting a position error of an electronically commutated actuator drive between an assumed position and an actual position of the actuator drive includes performing a position control procedure for the position of the actuator drive. The method further includes providing data with regard to the assumed position of the actuator drive. The method further includes forming an electric space vector value to generate a component of a stator magnetic field that extends parallel with a direction of an exciter magnetic field that prevails in the case of the assumed position of the actuator drive. The method further includes detecting whether a movement of the actuator drive has occurred as a result of generating the component of the exciter magnetic field.

Abstract: A controller of each power conversion device in a power conversion system controls a switching element unit, based on a detected value of reactor current flowing through a filter reactor, a detected value of output voltage output between the terminals of a filter capacitor, and a detected value of output current flowing through an output reactor. The controller generates a voltage command based on the output current and the output voltage and generates a correction amount of the voltage command based on the output current in which a reference frequency component is removed. The controller generates a current command based on the addition value of the voltage command and the correction amount and controls the switching element unit such that the reactor current matches the current command.

Abstract: An electric motor comprising: a stator; a rotor having a magnet mounted thereto; an electric circuit comprising a plurality of phases or windings for driving rotation of a rotor, in a drive mode; and a controller configured to control the electric circuit, in a motor braking mode, to short at least one of said phases or windings such that the magnet is able to generate a braking current in the shorted phase or winding wherein the motor is configured to operate at a rated current in the drive mode and to have a reactance such that the amplitude of the braking current is the same or lower than the amplitude of the rated current.

Abstract: In an embodiment, a method for detecting the angular position of the rotor of an electric motor includes an inductive-sense procedure implemented by applying to the windings of the electric motor a time sequence of position-detection pulse signals, detecting a corresponding time sequence of response signals, integrating the response signals, and recording respective times taken by the response signals to reach an integral reference threshold. The position of the rotor is detected as a function of the respective times. The integral reference threshold is established by fixing a peak value, applying to the windings a calibration pulse, detecting the corresponding response signal and determining the time taken to reach the peak value. The integral reference threshold is selected as the integral of the response signal.

Abstract: The present invention discloses a method for determining a rotor angle of a rotor of an electric machine, having the steps of producing a torque-dependent test signal which depends on the torque of the electric machine and has a higher frequency than a supply signal for the electric machine, controlling the electric machine using the supply signal and the test signal which is superimposed on the supply signal, recording phase currents of the electric machine, and determining the rotor angle of the rotor of the electric machine on the basis of the effects of the test signal on the phase currents. The present invention also discloses an angle determination apparatus and a corresponding control apparatus.

Abstract: A motor controller according to the present disclosure obtains the rotational speed determination signal of the motor through the microprocessor and the rotational speed collector, and then outputs the first control signal by the first logic operation circuit based on the speed of the motor, to make the driving circuit control the main circuit to work normally or enter the safety state. In addition, the motor controller generates and outputs the second shutoff signal by the monitoring chip based on the working state or the output instruction of the microprocessor, and then outputs the second control signal by the second logic operation circuit based on the second shutoff signal and whether the DC bus voltage of the main circuit is in an overvoltage state, to make the driving circuit control the main circuit to stop receiving the first control signal and enter the safety state.

Abstract: Provided is a control device for a permanent magnet-type rotating electrical machine (100), which includes a current coordinate transformation unit (109) configured to output a d-axis current and a q-axis current by coordinate transformation of three-phase AC currents respectively detected by current detection units (111, 112, 113), a current correction direction calculation unit (108) configured to calculate a current correction direction through use of the d-axis current and the q-axis current, and a current correction amount addition unit (102) configured to correct a d-axis current command and a q-axis current command based on the current correction direction. In this manner, an induced voltage is converged to lie within a maximum voltage circle in accordance with a power supply voltage.

Abstract: Method of driving a single-coil motor having a stator and a rotor and a coil, comprising the steps of: monitoring a position signal and determining when said signal passes a first threshold; b) providing control signals for energizing the coil; c) a predefined period later, providing control signals for stopping or reducing the energization of the coil; d) monitoring a second signal indicative of the coil current, and determining a third time when said signal passes a second threshold level; and monitoring the first signal, and determining a fourth time when said signal passes a third threshold level; e) updating the prediction period; f) repeating steps b) to e). A driver circuit adapted for performing such method. A system comprising such driver circuit.

Abstract: A multiphase driver device includes: one phase driver circuit of a first type including a first monitoring transistor and a first monitoring resistor generating a first voltage that is proportional to a first source current supplied to a one of the plurality of semiconductor switches; and a plurality of phase driver circuits of a second type each including a second monitoring transistor and a second monitoring resistor generating a second voltage that is proportional to that a second source current supplied to corresponding one of the remaining semiconductor switches, each of the plurality of phase driver circuits of the second type further including a comparator that compares the second voltage to the reference voltage, and a first regulating transistor that adds a first regulating current to the second source current in accordance with an output of the comparator.

Abstract: An apparatus for determining the position of the rotor of an electric machine in relation to the stator. The machine has multiple phases, each of which includes at least one pole winding with a magnetizable core. The apparatus includes devices for detecting measurement signals that are characterized by the momentary degrees of magnetization of the pole winding cores. The degrees of magnetization are influenced by the angular position of the magnetic field of the rotor. The devices are also used to detect the currents in the phases and determine the angular position of the rotor from the detected measurement signals, taking into account a contribution of the phase currents to the degrees of magnetization of the pole winding cores.

Abstract: An electric motor control device includes a control unit that controls operation of a drive circuit supplying electric power to an electric motor and a current sensor that detects current generated in the electric motor. The control unit detects fundamental high frequency current generated when the electric motor is applied with fundamental high frequency voltage for estimating the magnetic pole position, selects first electric angle and second electric angle corresponding to a d-axis direction of the magnetic pole position, detects first specific high frequency current generated when a position of the first electric angle is applied with specific high frequency voltage and second specific high frequency current generated when a position of the second electric angle is applied with the specific high frequency voltage, and compares the first and the second specific high frequency currents to estimate a positive d-axis direction of the magnetic pole position.

Abstract: A device for determining a rotor position in a polyphase electric motor having a first phase, a second phase and a third phase. A power control unit applies a first voltage on the first phase, and a second voltage on the second phase, the first voltage and the second voltage being periodic signals of opposite polarity, alternating between a first part and a second part of the alternating period, such as square waves. A sample unit samples a third voltage on the third phase for acquiring a first sample at a first instant in the first part and a second sample at a second instant in the second part, and a difference value between the first sample and the second sample. The difference value represents a mutual inductance between the stator coils due to the rotor position. A determination unit determines the rotor position based on the difference value.

Abstract: External power supply system includes an electrical storage device, motor, inverter that drives the motor by using electric power of the electrical storage device, and a control device controls the inverter. The inverter includes a first and second switching elements connected in series with each other between a positive and negative electrode power supply lines. A connection-node of the first and second switching elements is connected to one corresponding stator coil. The control device inputs signals to the inverter to drive the inverter such that voltage at the neutral point becomes a predetermined value. The control device compensates for signals in dead time period, the period in which off-state signals are supplied to the first and second switching elements, on the basis of current that is input from the connection-node to one corresponding stator coil or output from one corresponding stator coil to the connection-node while an engine is driven.

Abstract: A fan having one fan blade; a fan motor for rotating the fan blade; a motor control electrically coupled with the fan motor for controlling operational characteristics of the fan motor; and a power supply having a step-down high efficiency buck converter, a step-down low drop-out linear regulator, and/or a step-down switching regulator are described. The power supply may receive a first input voltage and lower the first input voltage to a second lower voltage. The fan motor is electrically coupled to be driven by the first input voltage and the motor control is electrically coupled to operate using the second lower voltage from the power supply. The motor control may include a microcontroller, level shifters electrically coupled to the microcontroller, and drivers electrically coupled to the level shifters and configured to drive the fan motor.

Abstract: A rotor position determination and tracking system for a dynamo electric machine includes a first AC power supply to inject a carrier wave into a main stator of the dynamoelectric machine and a second AC power supply to inject an excitation voltage or current into an exciter stator of the dynamoelectric machine. A plurality of current sensors and voltage sensors located at the exciter input lines sense current and voltage thereat. A first control logic receives the sensed current and voltage and outputs an estimated rotor position. A second control logic receives an estimated exciter field voltage or current rotating wave form angle and filtered sensed current or voltage signals from the first control logic and utilizes a known main stator carrier frequency to determine the rotor position. The rotor position is input into the first control logic to calibrate the first control logic for tracking of the true rotor position.

Abstract: A rotor position estimating device includes a voltage application unit, a current detecting unit and an estimating unit. The voltage application unit is configured to apply a d-axis voltage to an electric motor including a salient-pole rotor during a stop of the electric motor. The current detecting unit is configured to detect a q-axis current flowing through the electric motor at the time when the d-axis voltage is applied. The estimating unit is configured to estimate a rotor position during a stop of the electric motor on the basis of the q-axis current detected by the current detecting unit. The voltage application unit is configured to set a voltage application time in correspondence with peak timing at which the q-axis current reaches a peak in a transitional response characteristic of the q-axis current at the time when the d-axis voltage is applied.

Abstract: The system and method disclose for the controlling of motor switching. The system includes a controller unit having a control signal generator, a memory device, a processing unit, a signal acquisition device, and an analog-to-digital converter. A power stage has a plurality of switches and receives a control signal from the control signal generator and a power signal from a power source. The power stage drives two windings of the set of three stator windings with a multi-state pulse and leaves one stator of the three stator windings undriven. The processing unit acquires a demodulated measured voltage on the undriven winding. The processing unit communicates with the power stage to change which two windings of the three stator windings are driven when the demodulated measured voltage surpasses a threshold.

Abstract: The system and method disclose for the controlling of sequential phase switching in driving a set of stator windings of a multi-phase sensorless brushless permanent magnet DC motor. A motor controller controls a power stage that drives two windings of a set of three windings in the motor with pulse width modulated signal. A plurality of voltage values on an undriven winding of the set of three windings are sampled within a window of time, wherein a period beginning when the driven windings are energized and ending when the driven windings are de-energized encompasses the window of time. The sampled voltage values are processed. When the processed voltage values exceed a threshold, the motor controller changes which two windings are driven.

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: Methods and systems for starting an electric motor using a motor controller including a processor are provided. The method includes determining if the electric motor is operating, increasing a failed start counter if the electric motor is determined not to be operating, determining a reverse rotation by comparing a failed start counter to a predetermined threshold, and applying a reverse rotation start routine to the electric motor when a reverse rotation is determined.

Abstract: An apparatus detects the position of a rotor of an electric motor having three phases and a plurality of windings. The apparatus includes circuitry configured to connect at least two of said windings between first and second reference voltages according to a first current path disconnect said at least two windings, and allow the current stored in said two windings to be discharged through a second current path. The apparatus comprises a measuring circuit configured to measure the time period between the starting instant of storing the current in the two windings and the final instant of discharging the two windings and a rotor detector configured to detect the rotor position based at least in part on the measured time period.

Abstract: A method for determining the position of an at least two-phase, in particular three-phase bmshless electric drive comprising at least two phase windings, each of which has a first and a second terminal, a second terminal of a first phase winding being electrically connected to the first terminal of a second phase winding at a common connecting terminal. In order to be able to reliably determine the position of the electric drive even at low speeds, a voltage pulse is applied between the first terminal of the first phase winding and the second terminal of the second phase winding, the resulting voltage at the connecting terminal or at a third phase winding connected thereto is detected and the voltage ratio between the first phase winding and the second phase winding is determined therefrom, and the ratio between the variable inductances is determined from said voltage ratio.

Abstract: An estimating method for a rotor position of a motor and an estimating device for the same are disclosed herein. The estimating method includes injecting a first high frequency signal to the motor at a first estimating angle, generating a first sensing signal of the motor in a period when the first high frequency signal is injected to the motor, injecting a second high frequency signal to the motor at a second estimating angle, generating a second sensing signal of the motor in a period when the second high frequency signal is injected to the motor, determining a quadrant of an operating angle according to the first sensing signal and the second sensing signal, and acquiring the rotor position according to the first sensing signal, the second sensing signal, and the quadrant of the operating angle.

Abstract: To provide a parallel drive system that can reduce vibrations of an arm member and can realize positioning at a high speed even when a slave servomotor does not have a position detector, at a low cost. To achieve this object, a parallel drive system of the invention includes: a master servomotor and a slave servomotor that include linearly-moving movable units that are arranged in parallel to each other, respectively; and an arm member that forms a bridge between the two movable units. The system includes: a position detector detecting position information on the movable unit of the master servomotor; an acceleration sensor detecting acceleration information on the movable unit of the slave servomotor; a master servo amplifier controlling the master servomotor based on the position information; and a slave servo amplifier controlling the slave servomotor based on the position information and the acceleration information.

Abstract: A brushless wound field synchronous generator configured to generate an output power to drive an electrical load includes a rotating rectifier assembly. The rotating rectifier assembly includes a rotating diode assembly and a field effect transistor (FET) to control voltage across the rotating diode assembly.

Abstract: An apparatus for measuring a position deviation of a rotor of a permanent magnet synchronous motor includes a control unit, a power transformation unit, a rotor position estimator and a calculation unit. The control unit receives a d-axis DC voltage signal and a q-axis AC voltage signal and receives an initial value of the rotor position and a high-frequency signal to output a three-phase command signal. The power transformation unit receives the three-phase command signal and outputs a three-phase control signal for controlling the motor. The rotor position estimator receives a three-phase current feedback signal corresponding to an operation of the motor and generates an estimation value of the rotor position. The calculation unit performs calculation to the initial value and the estimation value to generate a deviation value of the rotor position. Moreover, a method for measuring the position deviation is also disclosed herein.

Abstract: An apparatus includes a sensorless field-oriented control (FOC) motor controller. The motor controller includes a pulse width modulation (PWM) controller configured to generate PWM signals and to provide the PWM signals to an inverter. The motor controller also includes an angle sampler configured to receive a commanded voltage angle signal and to provide the commanded voltage angle signal as an output signal in response to a triggering event. The triggering event is based on a voltage or a current associated with an input or an output of the inverter. The motor controller further includes a first combiner configured to combine (i) a feed-forward voltage angle signal and (ii) a second signal based on the output signal. The first combiner is configured to generate the commanded voltage angle signal. In addition, the motor controller includes a second combiner configured to combine a feed-forward voltage amplitude signal and the second signal.

Abstract: An example apparatus includes a controller configured to control operation of a salient-type, multiphase motor in accordance with a technique including periodic on and off-times, the motor including a stator and a rotor. The controller is configured to calculate or receive values representing changes in current to the motor during the respective on and off-times or measurements proportional thereto, and calculate an inductance of the motor as a function of the values and a supply voltage to the motor. And the controller is configured to determine a position of the rotor based on the inductance of the motor, and control operation of the motor based on the position of the rotor.

Abstract: A method for determining a rotor position of a two-phase synchronous machine including two strands. The method is useful for electronically commuting the synchronous machine. The method includes alternately actuating each of the strands in a first actuating time window with an actuating value of positive polarity and in a second actuating time window with an actuating value of negative polarity, where the first and the second actuating time window alternately follow each other. The method further includes applying an actuating value of 0 during a measuring time window which is provided within at least one of the actuating time windows of a strand. The method further includes applying a measuring pulse to the corresponding strand within the measuring time window in order to measure the inductance of the corresponding strand as an indication of the rotor position. In general, the strand inductance is dependent on the rotor position.

Abstract: In one embodiment, a method includes measuring between two consecutive electrical commutations of a brushless direct-current (BLDC) motor a current through the BLDC motor. One or more pulse-width-modulation (PWM)-configurable signals are driving the BLDC motor. The method includes determining a waveform of the current through the BLDC motor; if the waveform of the current through the BLDC motor comprises a first type, then increasing a duty cycle of each of one or more of the PWM-configurable signals driving the BLDC motor; and, if the waveform of the current through the BLDC motor comprises a second type, then decreasing a time interval between electrical communications of the BLDC motor.

Abstract: A method of controlling an electrical machine. The electrical machine includes a stator having a core and a plurality of windings, and a rotor disposed adjacent to the stator to interact with the stator. The method includes detecting a movement of the rotor, generating a three phase alternating current (AC) voltage signal by all phases of the electrical machine, monitoring for a transfer speed of the electrical machine, discontinuing the three phase AC voltage signal when the transfer speed is traversed, and switching to a back electromotive force (BEMF) control mode after discontinuing the three phase AC voltage signal.

Abstract: A controlling apparatus for an electric motor according to an embodiment includes a superposed component generator, an inverter, a current detector, and a magnetic pole position estimator. The superposed component generator generates, at a predetermined cycle, a superposed voltage reference of which vector is shifted by 90 degrees with respect to that of a superposed voltage reference previously generated, in a coordinate system that is set to a stator of the electric motor. The inverter outputs a driving voltage that is based on a driving voltage reference superposed with the superposed voltage reference to the electric motor. The current detector detects currents flowing into respective phases of the electric motor, and outputs the detected currents. The magnetic pole position estimator detects the magnetic pole position of the electric motor based on an amount of change in the detected currents at the predetermined cycle.

Abstract: A frequency converter and a method for determining the position of the rotor of an electric machine are provided. The frequency converter includes a load bridge and a control of the load bridge, for supplying electricity between the load bridge and an electric machine connected to the load bridge. The frequency converter includes a determination for at least one electrical parameter of the electric machine, and includes a determination for the position of the rotor of the electric machine. The load bridge is fitted to supply a first alternating electricity excitation signal, which is formed in relation to the electrical angle of the electric machine, to the electric machine. The frequency converter is further fitted to determine the first alternating electricity response signal corresponding to the first alternating electricity excitation signal, and the position of the rotor is determined on the basis of the first alternating electricity response signal.

Abstract: A position sensorless control methodology for electrical machines using high frequency flux vector signal injection in the estimated rotor flux rotational reference frame is provided. In one aspect, the estimated position error function is derived directly from the stator flux equation without any simplification. The method is applicable for electrical generator motoring mode operation from standstill and power generation mode operation.

Abstract: A voltage converter includes a first circuit and a second circuit. The first circuit includes two or more reactors and at least one switching element. One terminal of each of the reactors is connected in parallel with respect to a power source. The at least one switching element is connected to the other terminal of each of the reactors. The second circuit includes at least one rectifier of which one terminal is connected to the electrical load. The second circuit shares with the first circuit the at least one switching element connected to the at least one rectifier. The first circuit is connected such that the power source charges the respective reactors when the at least one switching element is turned ON. The second circuit is connected such that the reactors discharge power to the electrical load when the at least one switching element is turned OFF.

Abstract: In sequentially selecting and driving two phases of the three-phase stator windings of a synchronous motor, detect a speed electromotive voltage of a de-energized phase, relate the speed electromotive voltage to rotor position information beforehand, then count rotor position information backward based on the detected the speed electromotive voltage to estimate rotor position; and then detect rotation speed from the change rate of the rotor position information so as to achieve highly accurate position and speed control.

Abstract: A system. The system includes a processor, a first module, a second module and a third module. The first module is communicably connected to the processor and is configured for calculating a q-axis voltage component and a d-axis voltage component. The second module is communicably connected to the processor and is configured for determining a voltage angle relative to the q-axis. The third module is communicably connected to the processor and is configured for (1) comparing the determined voltage angle to a predetermined value, (2) outputting the determined voltage angle if the determined voltage angle is less than the predetermined value, and (3) outputting the predetermined value if the predetermined value is less than the determined voltage angle.

Abstract: A motor control apparatus according to an embodiment includes a power conversion unit and a control unit. The power conversion unit supplies power to a motor having salient pole characteristic. The control unit performs proportional-integral control on the deviation between a current reference and a current flowing into the motor to generate a voltage reference, and controls the power conversion unit on the basis of the voltage reference. The control unit estimates the magnetic-pole position of a rotor of the motor on the basis of a high-frequency current flowing into the motor by controlling the power conversion unit, and corrects the estimated magnetic-pole position on the basis of an integrated value of the proportional-integral control.

Abstract: A control apparatus is provided for controlling a multi-phase, switched reluctance motor. The control apparatus includes voltage adjusters, a controller, and a carrier signal generator. Each of the voltage adjusters adjusts a voltage applied to a corresponding one of voltage application targets on the same salient pole of a stator of the motor. The controller controls each of the voltage adjusters via a pulse-width modulation based on comparison between a command signal and a corresponding one of carrier signals, thereby controlling the voltage applied to the corresponding voltage application target to a command voltage indicated by the command signal. The carrier signal generator generates the carrier signals so that for at least one pair of the voltage application targets on the same salient pole of the stator, two of the carrier signals which respectively correspond to the pair of the voltage application targets are offset in phase from each other.

Abstract: A control apparatus for an AC rotary machine includes: a current detection section detecting current from a power converter to the AC rotary machine; and a control section generating a three-phase AC voltage instruction to the power converter, based on current detected by the current detection section and a torque instruction. The control section includes: an observer calculating a magnetic flux estimated value of the AC rotary machine, based on detected current and the voltage instruction; a current instruction calculation unit calculating current instruction values on rotational two axes, based on the torque instruction and the magnetic flux estimated value from the observer; and a voltage instruction calculation unit calculating the voltage instruction, based on the current instruction values from the current instruction calculation unit and the magnetic flux estimated value from the observer.

Abstract: A driving apparatus for an electromagnetic load, said apparatus having at least one pair of first and second transistors arranged so as to form a current path with the electromagnetic load for discharging the current produced by the electromagnetic load. The first transistor has an inherent diode between the non-drivable terminals and the apparatus is configured to control switching of the pair of first and second transistors, to diode-connect the second transistor, with said first and second transistors switched off, so that the current produced by said electromagnetic load, crossing said inherent diode, creates an overvoltage between the terminals of the second diode-configured transistor such to exceed the conduction threshold voltage thereof.

Abstract: To establish an initial/resting position of a permanent magnet rotor, all motor stator windings are stimulated (voltage applied thereto) in sequence, the time it takes for current in the stimulated stator winding to rise to a specific current value is measured for each stator winding and these time measurement results processed. From the measured time results rotor position to within 60 degrees is determined and the position sector is known prior to starting/rotating the motor. Once the rotor position is known, the next commutation point in a six step sequence is known before actually starting/rotating the motor. Position measurement winding stimulation may be interleaved with commutation pulses, or the unexcited stator winding may be stimulated between commutation pulses to the other two excited stator, wherein one of the two stator windings remains connected to the power and provides a current return path to the unexcited but stimulated stator winding.

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 for the motor at a stationary reference frame, the voltage having a frequency and the measured current being based on the voltage, a filter configured to obtain position information of the rotor based on the measured current and a nonlinear observer configured to estimate a rotor position of the motor during the stationary reference frame based on the position information. The controller is configured to control the motor based at least in part on the estimated rotor position.

Abstract: A method of estimating inductance of a permanent magnet synchronous motor (PMSM) includes injecting a signal having a frequency differing from an operating frequency of the PMSM into the PMSM during sensorless operation, sensing magnitudes of current responses to the injected signal, and estimating an inductance value at which the magnitude of the sensed current response is minimal to be an actual inductance value of the PMSM, thereby estimating inductance used in the PMSM regardless of position estimation error of the PMSM and thus more accurately and reliably estimating inductance of the PMSM.