Abstract: A motor drive control device 1_2 includes a target point determination unit 12_2 determining a target point P of zero crossing of a coil current Iu of a U phase based on a position detection signal Shu, a current zero crossing point estimation unit 14_2 estimating a zero crossing point Q of the coil current Iu of the U phase by detecting a change in a current direction of the coil current Iu of the U phase at a predetermined timing in every cycle of a PWM signal, an adjustment instruction signal generation unit 19_2 generating at least one of a phase adjustment instruction signal Sp for instructing phase adjustment of the coil current Iu and a frequency adjustment instruction signal Sf for instructing frequency adjustment of the PWM signal according to a phase difference ?? between the target point P and the zero crossing point Q such that the phase difference is within a predetermined range, and a drive control signal generation unit 16_2 generating a drive control signal Sd based on at least one of the phas

Abstract: A method of driving a three-phase motor includes, while a first phase is energized, driving a second phase using a first drive function which is sinusoidal. The first phase is switched to a non-energized state and a back electromotive force (BEMF) voltage of the first phase is detected. For at least a portion of a time when the first phase is non-energized the driving of the second phase depends on the output of a second drive function different from the first drive function. The second drive function may be non-sinusoidal and may be a cosine function. The second drive function may drive the second phase when the output of the second drive function is a modulation ratio less than 1. When the output of the second drive function is a modulation ratio greater than or equal to 1 the second phase may be driven to a modulation ratio of 1.

Abstract: A current state determination method is configured to determine a state of current passing through a coil of a motor and includes: at a first time point when a high side transistor and a low side transistor are switched to a cut-off state, measuring a voltage of a node where the high side transistor, the low side transistor and the coil are coupled, so as to output a first voltage; at a second time point when the high side transistor and the low side transistor are maintained in the cut-off state, measuring the voltage of the node, so as to output a second voltage; comparing the first voltage and the second voltage to obtain a comparison result; and determining the state of the current according to the comparison result. The present disclosure also provides a current state determination circuit for performing the current state determination method.

Abstract: A method of controlling the commutation of a brushless direct current motor includes providing sensors which provide a variable output dependent on rotational angle or the relative position of the stator and rotor of the motor. Output from the sensors is sampled at a time between a past commutation event and the next commutation event to be implemented. An angular position between the rotor and stator is determined at the time. The time of the next commutation event is determined based on the next commutation angle, motor speed, and the determined angular position.

Abstract: In one embodiment, a motor control circuit may be configured as a current circuit that forms a sense current that is representative of at least a BEMF voltage from a motor, and to use the sense current to detect a substantially zero-crossing of the BEMF voltage.

Abstract: A lead angle estimator is provided for estimating a lead angle of a brushless DC motor. The lead angle is the angle between a phase-voltage-vector of a phase-voltage, and a phase-current-vector of a phase-current. The lead angle estimator comprises a sampling unit and a processing unit. The sampling unit is adapted for obtaining phase-samples, which are a measure of the phase-current. The processing unit is adapted for estimating the lead angle by calculating a difference of the phase-samples in a extremum period around a maximum or around at least the phase-voltage, and by normalizing the obtained difference.

Abstract: A method for controlling a multiphase synchronous motor, for a motor flux vector includes setting a first winding of the motor to a floating state in which the first winding is electrically floating; setting a voltage across a second winding of the motor for a first period; receiving first voltage samples associated with the first winding in the first period; setting the voltage across the second winding to a second period, in which the first period and the second period are periods of one or more pulse width modulation cycles, in which a polarity of the voltage across the second winding in the second period is opposite to a polarity of the voltage across the second winding in the first period; receiving second voltage samples associated with the first winding in the second period; and determining a position of the rotor based on the first and second voltage samples.

Abstract: A system and a method of driving a motor are provided. A zero crossing reference module defines a zero-crossing region based on a current zero-crossing point of a coil of the motor, and a mode switching setting module sets a reference parameter of a back electromotive force when the motor rotates at a preset rotating speed. When the current zero-crossing point fails to fall in the zero-crossing region, a driving mode selector module selects a voltage detection mode. When a parameter of the back electromotive force is equal to the reference parameter, the driving mode selector module selects to switch back to a current detection mode. A motor driving controller module calculates a position of a rotor of the motor based on the current in the current detection mode and determines the position based on the back electromotive force in the voltage detection mode to drive the motor.

Abstract: A movable barrier opener system having a multiphase brushless DC motor in the drive assembly is provided. The multiphase brushless DC motor may impart motive force to a movable barrier in response to barrier movement instructions from the barrier operator controller to the drive assembly. The barrier operator controller of the movable barrier opener system is configured to detect a back EMF of at least one winding of the multiphase brushless DC motor and determines a position of the movable barrier and/or determines a torque of the multiphase brushless DC motor in response to the detected back EMF. A position sensor and a back EMF sensor module provides actual operating parameters to the controller.

Abstract: A method of controlling an electric power assisted steering (EPS) system comprising one or more inverter bridges each connected to a multi-phase motor configured to provide power assist to steering of a vehicle, wherein each inverter comprises a plurality of switching elements each associated with a phase of the motor, the method comprising in response to detecting a predefined event affecting current flow in one or more of the inverter bridges, preventing current flow in said one or more affected inverters by applying a gate-source voltage to one or more of the switching elements of the affected inverter bridge(s), wherein the switching elements are configured to conduct in the off-state when reverse biased beyond a reverse conduction threshold voltage, and wherein applying the gate-source voltage comprises applying a negative gate-source voltage to control the reverse conduction threshold voltage of the switching elements in the off-state only at a time when there is no current flowing in the direction drai

Abstract: In order to shorten an activation time while realizing high accuracy motor control, a motor control apparatus operable to control a motor is provided. The apparatus comprises: a first drive control unit configured to drive the motor by forced commutation control; a second drive control unit configured to drive the motor by vector control; and a control unit configured to control to drive the motor by one of the first drive control unit and the second drive control unit. A first control period which is a control period in which the first drive control unit controls the motor is shorter than a second control period which is a control period in which the second drive control unit controls the motor.

Abstract: An actuator driving device includes: first and second half bridge circuits driven according to modulated drive signals having an inverted relationship, generates a drive voltage for an actuator by switching a DC voltage, and outputs the drive voltage to the actuator; a current detection resistor which generates a current detection signal corresponding to current flowing through a series circuit including first and second switching elements and a series circuit including third and fourth switching elements; a hold circuit which holds the current detection signal from the current detection resistor and generates an output signal; a comparator which compares the output signal with a target amplitude signal to generate a comparison result signal; a multiplier which multiplies the comparison result signal and the drive signal to generate a multiplication result signal; and a PWM modulator which performs PWM modulation according to the multiplication result signal to generate a modulated drive signal.

Abstract: A vehicle includes a five-phase electric machine with open windings driven at each side by phase legs of an inverter. A controller monitors for open-circuit windings. In response to detecting an open-circuit winding above a predetermined speed threshold, the controller operates the inverter to drive the windings that are not open-circuited in a square configuration.

Abstract: A method and circuit for controlling or starting a U-shape single phase synchronous permanent magnetic motor (U-SPSPM motor) having a rotor and a stator and coupled to a single phase alternating current (AC) power source through a switch, including estimating back electromotive force (back-EMF) of the motor based on an observer model with inputs indicative of the measured signals, and triggering the switch to supply power to the motor based on the estimates of the back-EMF.

Abstract: A control device comprises a driving unit configured to drive a plurality of coils of a multiple-phase motor by pulse width modulation; a detection unit configured to detect currents flowing through the plurality of coils in a time-division manner; and a change unit configured to change, in accordance with a duty in the pulse width modulation, a sequence of detecting the currents flowing through the plurality of coils by the detection unit.

Abstract: The present disclosure provides a system and method to determine at least one parameter of a motor, such as an inductance. The inductance can be determined, such as based on one or more digitally sampled motor winding currents. A digital filter can be applied to the digital samples such as to determine a slope of the motor winding currents. The digital filter can include a least squares fit that can be applied to the digital samples, such as to determine a slope of the motor winding currents. The least squares fit can be determined based on a computation of central tendencies such as an average value of time, an average value of current, an average value of the square of time, and the average value of the product of time and current. The average values can be determined recursively to provide improved computational speed.

Abstract: A motor driving device and a motor system that can reduce a torque ripple of a motor are provided. The current control loop detects a drive current of the motor, detects an error between the detected value of the drive current and a current indication value as a target value of the drive current, and determines the duty of the PWM signal reflecting the error concerned. The back EMF phase detector detects the phase of a back electromotive force of each phase in the motor. The torque correction unit calculates a first torque correction coefficient of a periodic function based on the phase variations in the three phases of the back electromotive force, and corrects the current indication value superimposing the first torque correction coefficient on the current indication value.

Abstract: The phase of a drive current of a motor is optimized. The phase arithmetic unit PHCAL calculates a drive voltage phase ?drv to converge the phase difference between the reference voltage phase ?bemf and the reference current phase ?i to zero based on a prescribed arithmetic expression. The phase correction unit PHCP determines the phase ?drvR after the correction by adding a correction value to the phase ?drv, and the magnitude of the correction value is updated by a feedback control so as to converge to a prescribed value the phase difference between the reference voltage phase ?bemf and the reference current phase ?i which are inputted. A PWM controller shifts an energization control timing synchronized with the reference voltage phase ?bemf based on the corrected phase ?drvR, and generates the PWM signal for controlling the drive voltage to a sine wave shape.

Abstract: An electronic device is for controlling motor drive circuits for driving a multi-phase motor in a force assisted system. Each motor drive circuit selectively permitting current to flow into or out of a respective phase of the multi-phase motor connected to the motor drive circuit in response to being driven by respective control signals. A motor control circuit generates the control signals. A fault processor detects at least one fault condition causing a fault current in a first motor drive circuit. In the event of the fault condition being detected, at least one alternative control signal is generated for at least one motor drive circuit for permitting at least one compensation current to flow for reducing a faulty force due to the fault current.

Abstract: The present disclosure provides a device and a method for driving a motor that demonstrates low noise and/or low vibration. A pulse-modulated control pulse signal S2 is generated by a driving signal generation portion 310 at each phase. A driving voltage VU˜VW, with duty cycle corresponding to the control pulse signal S2 and being inserted with specific idle time is applied to coils LU˜LW at each phase. A current phase detection signal S3 indicating a phase of the current IL flowing through the coil LU is generated by the current phase detection portion 330 at a specific phase (the phase U) corresponding to the control pulse signal S2 according to a pulse width of a terminal voltage VU at one end of the coil LU of the phase U.

Abstract: A method of controlling a brushless permanent-magnet motor. The method includes dividing each half of an electrical cycle of the motor into a conduction period followed by a primary freewheel period. The conduction period is then divided into a first excitation period, a secondary freewheel period, and a second excitation period. The method then involves exciting a winding of the motor during each excitation period and freewheeling the winding during each freewheel period. The secondary freewheel period has a position and length within the conduction period that acts to reduce the harmonic content of current in the winding relative to back EMF in the winding. As a result, the efficiency of the motor is improved.

Abstract: Motor drives and control methods are presented for sensorless motor speed control in which inverter output currents are sampled from the inverter output and a frequency modulation value is determined based on the current feedback. A speed or frequency setpoint is adjusted at least partially according to the frequency modulation value to provide an adjusted frequency or speed setpoint value that is then used in controlling the inverter to provide stability control to mitigate hunting or motor stoppage.

Abstract: Provided is a metal-insulator transition (MIT) transistor system including an MIT critical current supply device allowing MIT to occur between a control terminal and an outlet terminal of an MIT transistor for easily and conveniently driving the MIT transistor. A current supplier according to the present invention provides a critical current for allowing an MIT phenomenon to occur between the control terminal and the output terminal of the MIT transistor.

Abstract: In one aspect of the teachings herein, an interface circuit obviates the need for a microcontroller with multi-channel PWM capability in the context of controlling a brushless, three-phase DC motor. Instead, the interface circuit generates the requisite set of motor-phase control signals using a single PWM channel from the microcontroller. The interface circuit is implemented as a standalone integrated circuit (IC) in one embodiment, and is integrated into a pre-driver circuit in another embodiment.

Abstract: A method and system for controlling a motor is provided. In particular, various embodiments of the present disclosure describe a method and system for controlling a spindle motor in a hard disk drive (HDD) A method of controlling a motor is provided, the motor including a 3-phase synchronous motor with three terminals of an electromagnetic winding configuration. The method includes providing an input voltage between two of the terminals and measures a resultant silent terminal voltage at the third terminal, which is thereafter used in determining a rotor position. A corresponding system for controlling a motor is further provided.

Abstract: Motor Drive Control Device configured to properly start up various types of motors under operating conditions where motor operations are performed in a wide range of temperature and power supply voltage, includes output drive controllers that supply PWM drive output signals to an output pre-driver in such a manner as to minimize the error between a current instruction signal and a current detection digital signal. In response to a detected induced voltage generated from a voltage detector upon startup of a motor, an initial acceleration controller supplies initial acceleration output signals specifying a conducting phase for initial acceleration of the motor to the output drive controllers. The initial acceleration controller, the output drive controllers, and an output driver make a conducting phase change and perform a PWM drive to provide the initial acceleration of the motor.

Abstract: A method of determining the position of a rotor of a permanent-magnet motor. The method includes sequentially exciting and freewheeling a winding of the motor. The winding is freewheeled for a freewheel period in response to current in the winding exceeding a current limit. The method also includes measuring a parameter that corresponds to either the magnitude of current in the winding at the end of the freewheel period or the interval between the start or end of the freewheel period and the time at which current in the winding exceeds the current limit. The measured parameter is then compared against a threshold and the rotor is determined to be at a predetermined position when the measured parameter is less than or greater than the threshold.

Abstract: A method of determining the position of a rotor of a permanent-magnet motor. The method uses two different schemes to determine the position of the rotor. A first scheme is used when the rotor rotates within a first speed range, by sequentially exciting and freewheeling a winding of the motor, measuring a parameter that depends on the rate of change of current in the winding, and comparing the parameter against a threshold. A second scheme is used when the rotor rotates within a second speed range, by generating a voltage signal that is proportional to the voltage across the winding, generating a further voltage signal that depends on the rate of change of current in the winding, and comparing the two signals.

Abstract: Back electromotive force (BEMF) of a brushless DC (BLDC) motor may be determined when using continuous sinusoidal drive by computing the voltage to common (ground) of each phase (3) thereof when a phase current is substantially zero. These phase voltages may be computed from the DC supply voltage and the duty cycle of the pulse width modulation (PWM) drive to each of the motor phases. From the three phase voltages computed at a zero phase current occurrence, each coil voltage may be calculated. The BEMF of that coil is substantially equal to the coil voltage when at zero current. The phase voltages, when computed at a zero current instance, may be used in determining the BEMF. Once the BEMF is determined it may further be used to regulate the motor speed using a K factor of the BLDC motor.

Abstract: A method is provided for determining a phase current direction and a zero-crossing moment of the phase current in a sinusoidally controlled brushless direct current motor. The brushless direct current motor comprises a coil per phase and the phase of the brushless direct current motor is driven by a half bridge driver. The half bridge driver comprises a high side field effect transistor and a low side field effect transistor. The method comprising the following steps: measuring the drain source voltage over the high side field effect transistor and low side field effect transistor, and determining the zero crossing moment of the phase current by determining the current direction based on the measured drain source voltages and by determining the moment the current changes direction.

Abstract: A sensorless brushless motor control device includes a first amplification module common to all motor phases and generating an intermediary voltage signal, a voltage divider between each motor phase and a node on which the intermediary voltage signal is generated, and a computation unit. Each voltage divider generates a first corrected electromotive force with a predetermined average value. The computation unit controls the motor on the basis of the first corrected electromotive forces. By using only hardware components, the control device maintains the average of the corrected electromotive forces at the center of the analog acquisition zone of the computation unit.

Abstract: A method for determining a position of an armature of a synchronous machine relative to a stator of the synchronous machine includes the steps of applying to the synchronous machine a plurality of test current vectors, with each test current vector having identical current magnitude and a different angle in relation to an armature-related d,q coordinate system, during application of the test current vectors to the synchronous machine, determining values of a physical response quantity of the armature proportional to the q component of the test current vectors, determining a first harmonic of the determined values of the physical response quantity as a function of the angle, and determining the position of the armature relative to the stator as a zero crossing of the first harmonic where a first derivative of the first harmonic is positive.

Abstract: There are provided a motor driving apparatus and method, the motor driving apparatus including: a filter controlling unit detecting a frequency of a pulse width modulation (PWM) signal and generating a control signal; a first filtering unit filtering a back electromotive force (BEMF) signal according to the control signal; a second filtering unit filtering a reference signal according to the control signal; and a comparing unit comparing output of the first and second filtering units and generating a motor rotor detection signal.

Abstract: Disclosed herein is a motor driving apparatus, including: an inverter applying a direct current voltage to the respective phases of a brushless DC (BLDC) motor by a switching operation; and a motor driver detecting counter electromotive force patterns in floating sections of the respective phases, detecting zero cross points (ZCPs) of the respective phases using the counter electromotive force patterns, and then generating a PWM signal for controlling a switching operation of the inverter and a phase switching of the respective phases using position information of the zero cross points (ZCPs).

Abstract: A motor driving control apparatus may include a zero cross point (ZCP) detecting unit detecting back electromotive force generated by a motor apparatus and detecting a plurality of zero cross points in the back electromotive force, a zero cross point correcting unit correcting the plurality of zero cross points when a time interval between the plurality of zero cross points is equal to a predetermined error period or longer, and a controlling unit controlling driving of the motor apparatus using the plurality of corrected zero cross points.

Abstract: A system for determining motor speed of a brush DC motor in an apparatus, including a first filter for receiving a substantially DC component of the motor current and parameters corresponding to the brush DC motor, for calculating a speed estimate thereof; an adaptive bandpass filter having a center frequency corresponding to the speed estimate of the first filter, for receiving the motor current and substantially isolating a periodic current fluctuation thereof; a block for determining a frequency of the periodic current fluctuation, the current fluctuation corresponding to motor speed of the brush DC motor. The adaptive bandpass filter uses debounce filtering to reduce rapid filter passband switching, and a run-in period prior to passband switching to obviate transient effects of filter switching.

Abstract: There are provided a motor driving control apparatus, a motor driving control method and a motor system using the same. The motor driving control apparatus includes: a back-electromotive-force detecting unit detecting back electromotive force generated by a motor apparatus; a floating correcting unit, if zero-crossing has not occurred in a current floating area, correcting the floating area by predicting a time at which a zero-crossing occurs; and a control unit determining a zero-crossing time of the back electromotive force based on an output from the floating correcting unit and controlling driving of the motor apparatus using the determined zero-crossing time.

Abstract: There are provided a motor driving control apparatus, a motor driving control method, and a motor system. The motor driving control apparatus includes: a zero-crossing detecting unit detecting back electromotive force generated in a motor apparatus and detecting a zero-crossing point of the back electromotive force; a commutation point calculating unit calculating an average value for zero-crossing points detected at least three times to determine a commutation point using the calculated average value; and a control unit controlling a phase change of the motor apparatus using the commutation point.

Abstract: A back electromotive force (BEMF) zero cross may be detected in a brushless direct current (BLDC) motor that is controlled by pulse width modulation (PWM). A phase input of the BLDC motor is tri-stated during PWM periods in which the phase input conducts motor drive current, and the tri-stating of the phase input is used to determine whether a BEMF zero cross has occurred in the BLDC motor.

Abstract: A driving device for a brushless DC motor having at least one coil ma include a voltage zero crossing detection unit to where an induced voltage becomes zero; a detection period setting unit to set at least one detection period synchronously with the voltage zero crossing point; a coil voltage detection comparator to compare a terminal voltage generated from one end of the coil with a threshold voltage, and generate a coil voltage detection signal indicating a comparison result; a current phase detection unit to generate a phase detection signal indicating a relationship between a phase of a coil current flowing through the coil and a phase of the induced voltage; a driving signal synthesis unit to generate a driving control signal based on the phase detection signal; and a driving circuit to drive the brushless DC motor based on the driving control signal.

Abstract: A device may detect the zero-cross event of a BEMF of an electric motor with first, second, and third phase windings driven by respective first, second, and third power driving stages. The device may include a control circuit configured to place at an impedance state the third power driving stage relative to the third phase winding, the third phase winding being coupled to a zero-cross detecting circuit, introduce a masking signal to mask an output signal of the zero-cross detecting circuit in correspondence with each rising edge of a first driving signal of the first power driving stage relative to the first phase winding, and determine whether a first duty-cycle of the first driving signal is such that a duration of a masking window of the masking signal is greater than an on-time period of the first driving signal.

Abstract: A motor control circuit and associated techniques detect a zero crossing of a current in a motor winding by detecting a reverse current in a half bridge circuit used to drive the motor winding.

Abstract: A motor control circuit and associated techniques can adjust a phase of a motor drive to keep a rotational reference position of an electric motor at the same relative phase as a zero current in a motor winding at different motor speeds and as the motor accelerates and decelerates. In some embodiments, a particular circuit and technique can be used to detect the zero current in the motor winding.

Abstract: A controller for a brushless motor that includes a PWM module configured in half-bridge or full-bridge mode. The PWM module outputs control signals for controlling the excitation of a winding of the motor, and one of the duty cycle and the period of the PWM module defines a time at which the winding is commutated.

Abstract: A method and apparatus for dynamically adjusting a dead time of a BLDC motor during a phase change detect the winding current of the BLDC motor during the dead time, and terminate the dead time when the winding current is detected to be substantially or close to zero. Thus, the method and apparatus can optimize the dead time and switch the BLDC motor between two phases at a zero-current point, without reducing the maximum rotation speed of the BLDC motor.

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: The invention relates to a method for operating an electronically commutated electric machine (2). Alternating phase voltage potentials are applied to the phase conductors of the electric machine (2) for commutation, said phase voltage potentials being generated by a pulse-width modulation so that the height of the applied phase voltage potential is determined by a duty cycle (TV) of the pulse width modulation. In order to determine an instant of a zero crossing of a current induced in a phase conductor, a blanking interval (AT) which represents a time slot, is provided, when no phase current potential is applied to the corresponding phase conductor. A first transition time slot (ÜT1) is provided prior to and/or after the blanking interval (AT) during which the progression of the applied phase voltage potential has a defined first gradient during.

Abstract: An electric household appliance (1) having a casing (2); a laundry drum (3) mounted inside the casing (2) to rotate about an axis of rotation; a three-phase asynchronous motor (6) for rotating the laundry drum (3); and a sensorless safety system (7) for determining rotation of the rotor (32), to determine rotation or no rotation of the laundry drum (3). The sensorless safety system (7) is designed to supply three direct currents (las, lbs, Ics) to the three stator power phases (31) during a predetermined time interval (?T), so as to magnetize the rotor (32); to cut off supply of the direct currents (las, lbs, Ics); to determine the time pattern of at least one of the three induced currents (Iar, Ibr, Icr) induced in the stator (30) in response to magnetizing the rotor (32); and to determine rotation or no rotation of the rotor (32) on the basis of the time pattern of at least one of the three induced currents (Iar, Ibr, Icr).

Abstract: Systems, methods, and other embodiments associated with back-EMF detection for motor control are described. In an embodiment, an apparatus includes a drive circuit configured to apply excitation signals to respective inputs of a motor, a signal inhibit circuit configured to convey a signal to inhibit application of the excitation signals during an interval, and a measuring circuit configured to measure a back-electromotive force (EMF) signal crossing a reference signal during the interval.

Abstract: A permanent-magnet AC motor comprises a motor and a controller coupled to the motor. The motor includes a winding. The controller includes a drive model configured to provide a drive current. Waveform of the drive current is spatially symmetrical. The winding has a waiting zone having electrical angle of 30° and a driving zone having electrical angle of 150° in each half electrical cycle when the motor is in operation. The driving zone is equally divided into five driving sub-zones.