Abstract: A method is disclosed for controlling a synchronous motor by determining a rotor position of the synchronous motor based on estimating a flux linkage. The method includes applying a voltage of a stator winding of the motor to a transfer function. The transfer function includes an S-domain integration operation and an error correction variable. An output of the transfer function is processed to compensate for the error correction variable introduced in the transfer function. An estimated flux linkage is generated and an angle of the rotor position is computed based on the flux linkage. The computed rotor position is input to a controller for controlling a position or speed of the motor.

Abstract: A driving system for a tri-polar electric motor comprises three phase windings. Winding drivers drive each winding with a driving waveform having a non-zero driving phase and intervals wherein the input is equal to zero at the start, middle and end of each driving phase. Using a driving waveform of this type enables monitoring of the back EMF in the winding during each interval when the input is equal to zero. This enables regular monitoring of the zero crossing point of each winding and hence of the position of the rotor. This enables the motor to operate efficiently without generating a torque ripple.

Abstract: Disclosed is a linear electric motor having a fixed primary comprising a stator divided into a number of sections, including a translating secondary having an operative length longer than any two adjacent sections of the stator in the form of a reaction plate, and a connecting means for connecting only those sections of the stator that are at least partially covered by the reaction plate. The position of the reaction plate relative to the stator is determined by monitoring current in the active representative sections. Power is supplied to each stator section individually, with power supplied in a modulated manner to end active stator sections only partially covered by the reaction plate. A measurement of the current to the active representative section is used to control output voltage to all energized stator sections and is used to determine the change in position of the reaction plate.

Abstract: A control method for a sensor-less, brushless, three-phase DC motor. A pulse-width modulation (PWM) duty cycle may be calculated. A voltage induced by rotation of a rotor may be sampled at a first expected zero crossing value to produce a first sampled voltage value. An average of a plurality of sampled voltage values, including voltage values sampled at a plurality of prior expected zero crossing values and the first sampled voltage value, may be calculated. The first sampled voltage value may be subtracted from the calculated average to produce a delta zero crossing error (ZCE). The current value of an integral term corresponding to a rotational period may be updated according to the sign of the ZCE. The integral term may be updated periodically and multiple times during each rotational period. The ZCE may be subtracted from the integral term, and the resulting value may be used to generate one or more time values.

Abstract: If magnitude relations between the output terminal voltage based on a DC negative terminal of the inverter and a threshold voltage that is a fixed value are compared, polarity thereof is changed at a predetermined rotor phase. The magnitude relation, for example, is detected by an inexpensive and simple apparatus such as a level shift circuit and a NOT circuit. The rotor phase of the permanent magnet synchronous motor is inferred on the basis of changes in the magnitude relation and if it is differentiated, a rotation speed is inferred. If the inferred values of the rotor phase and rotation speed are fed back to synchronous operation or vector control, the free-running permanent magnet synchronous motor is restarted.

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 method of the Pulse Amplitude Modulation for the Sensorless Brushless motor, which includes a start-up circuit, a phase detect circuit, a phase commutation circuit, a driving circuit, BEMF detection circuit, and frequency detector, utilizes the control signal of the phase commutation circuit to control the driving circuit so as to drive the outer motor coil and detect the control signal for the driving motor driving circuit by a detection circuit. The motor system can be controlled to reduce the discharge speed to avoid the motor driving circuit shutdown and further speed up the start-up time for the next charging period of the motor driving circuit to achieve the effect of low speed rotation and power saving.

Abstract: A method is described for operating an electric motor. The electric motor has at least two phases and a rotor. In the method, a current angular position (phipos) of the rotor is ascertained and, as a function of that, in at least one of the two phases, a potential is applied in such a way that a desired angular position (phiposreq) is achieved. From the current angular position (phipos) and the desired angular position (phiposreq) a setpoint angular velocity (dphides) is ascertained, which is used for influencing the potential.

Abstract: A dryer with a drying chamber that includes a process air duct for guiding process air through the drying chamber, a heat pump with a heat sink in the process air duct and through which air can flow in an outlet air direction for cooling down the process air, and a heat source arranged in the process air duct and through which air can flow in an inlet air direction for heating up the process air. The outlet air direction and the inlet air direction are substantially parallel to one another. The heat sink and the heat source are in a plane substantially perpendicular to the outlet air direction and to the inlet air direction alongside one another.

Abstract: A method for determining the position of a moving rotor in a switched reluctance motor includes the steps of applying a voltage to a phase winding of the reluctance motor, sampling a signal representative of the current magnitude in this phase winding, detecting a feature of the second temporal derivative of the signal, and determining the position of the moving rotor taking into account the occurrence of this feature. Apparatus for carrying out the method is described.

Abstract: A torque ripple suppression control device for a permanent magnet motor includes a current command conversion unit that outputs a current command value, a position detector that detects a rotational position of the permanent magnet motor, a current detection unit that detects a current at the permanent magnet motor, an induced voltage coefficient setting unit that outputs an information signal related to an induced voltage coefficient for an induced voltage at the permanent magnet motor, a torque ripple suppression operation unit that outputs a current correction command value for the permanent magnet motor, a current control operation unit that outputs a voltage command value based upon addition results obtained by adding together the current command value and the current correction command value and the current detection value, and a power converter that outputs a voltage with which the permanent magnet motor is to be driven.

Abstract: A method for determining a time for a zero crossing of a phase current in a polyphase electrical machine (2). The method including driving a driver circuit (31; 50) for providing phase voltages to operate the electrical machine (2); deactivating a pulse-width-modulated driving by at least one power switch (36, 37; 52, 53), such that no potential is applied to connecting nodes (AI, A2, B1, B2) by the driver circuit (31; 50), at least during a time segment in each cycle of the pulse width modulation; detecting a diode voltage via a freewheeling diode, with which the deactivated power switch (36, 37; 52, 53) has been provided, within the time segment; and fixing the time for the zero crossing of the phase current as the time after which there is no longer a diode voltage present across the freewheeling diode (40; 54) within the time segment.

Abstract: A motor control device includes an inverter circuit having switching elements on/off controlled according to a predetermined PWM signal pattern to convert an input direct current to three-phase alternating current supplied to drive an electric motor. A phase current of the motor is detected based on a detection of the input direct current and the PWM signal pattern. A PWM signal generation unit which generates a three-phase PWM signal pattern to enable detecting two-phase currents twice in synchronization with four time-points within a carrier wave period of the PWM signal respectively and so that the detection of current follows a magnetic pole position of the motor. A current differential unit supplies, as current differential values, differences between twice detected current values regarding the two phases respectively, and a magnetic pole position estimation unit estimates the magnetic pole position of the motor based on the current differential values.

Abstract: An apparatus and method for use with a PMSM detect the fall time or the rise time and the fall time of a motor current in the PMSM under different voltage vectors when the PMSM is in start-up to determine an initial rotor position for the PMSM at standstill.

Abstract: A control device includes a drive controller that controls the driving of an electromagnetic coil, and a regeneration controller that controls the regeneration of power from the electromagnetic coil. The drive controller includes an excitation interval setting unit that sets excitation and non-excitation intervals such that voltage is applied to the electromagnetic coil during the excitation interval but is not applied during the non-excitation interval. The excitation and non-excitation intervals are symmetrical with centers that respectively correspond to the ?/2 and ? phase points of the induced voltage waveform. The regeneration controller includes a regeneration interval setting unit that sets regeneration and non-regeneration intervals such that power is regenerated from the electromagnetic coil during the regeneration interval but is not regenerated during the non-regeneration interval.

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: According to one embodiment, a sensorless control apparatus for a synchronous motor, includes a PWM processing unit which pulse-width-modulates a three-phase voltage command, and thereby generates a gate command for an inverter, a high-frequency voltage calculator which obtains a high-frequency voltage component included in an output of the PWM processing unit or an equivalent output value, a high-frequency current calculator which obtains a high-frequency current component included in a current response value from a synchronous motor driven by the inverter, and an estimated angle calculator which calculates an estimated phase angle indicative of an estimated value of an angle of rotation of the synchronous motor, based on a plurality of pairs each including the high-frequency voltage component and the high-frequency current component which respectively include cosine components or sine components at an equal frequency, the pairs obtained for at least two different frequencies.

Abstract: Provided is a motor control device including a voltage specifying unit which generates a specified voltage signal indicating a target value of an applied voltage to a motor on the basis of a specified current signal indicating a target value of supplied current to the motor, so as to control the motor in accordance with the specified voltage signal. An update unit is further provided, which sequentially updates a specified field current signal that is a field current component of the specified current signal to be given to the voltage specifying unit on the basis of difference information between a value of the specified voltage signal and a limit voltage value defined as an upper limit value of the applied voltage. The update unit includes a low pass filter. The specified field current signal after the update is generated on the basis of a signal obtained by passing the specified field current signal before the update through the low pass filter and the difference information.

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 multiphase alternating current permanent magnet synchronous electric motor is coupled to an actuator. A sensorless electric motor drive control system controls operation of the electric motor. An initial phase angle and a rotational speed of a rotor of the electric motor are estimated. Operation of the sensorless electric motor drive control system and the electric motor are monitored using the estimated initial phase angle and the estimated rotational speed of the rotor of the electric motor. A fault in one of the sensorless electric motor drive control system and the electric motor is detected based upon the monitored operation.

Abstract: Methods and systems for controlling an electric motor are provided. The electric motor includes at least one winding. A winding current flowing through the at least one winding is monitored. The winding current has an oscillating component and an offset component. The offset component of the winding current is isolated from the oscillating component of the winding current. The electric motor is controlled based on the offset component of the winding current.

Abstract: A control method for a brushless, three-phase DC motor. A voltage induced by rotation of a rotor may be sampled at a first expected zero crossing value to produce a first sampled voltage value. An average of a plurality of sampled voltage values, including voltage values sampled at a plurality of prior expected zero crossing values and the first sampled voltage value, may be calculated. The first sampled voltage value may be subtracted from the calculated average to produce a delta zero crossing error. A pulse-width modulation duty cycle may be adjusted based on the delta zero crossing error. The pulse-width modulation duty cycle may be used to control a rotational velocity of the rotor.

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: This invention relates to an apparatus and method for deriving speed and position information for an electric motor. Apparatus for and a method of controlling a motor 100 are also disclosed. The apparatus for providing information relating to the operation of an electrical motor 100 comprises a sampler 50, 51 for sampling the instantaneous motor current is and a processor 160 for determining the instantaneous rate of change of the motor current and providing information about the motion or position of said motor based on said instantaneous rate of change of the motor current. In this way speed and position information can be provided, at low speeds, and without using a speed sensor.

Abstract: Slow speed operation of a brushless DC (BLDC) motor is enhanced by gating off some of the PWM pulses in each commutation period. By doing so, longer PWM pulse widths may be used at PWM signal frequencies that are inaudible while still allowing desired slow speed operation of the BLDC motor. Centering the non-gated PWM pulses in each commutation period where peak back EMF occurs, further reduces losses and improves delivery of maximum torque from the BLDC motor.

Abstract: The adapting system for a resonant drive appliance includes a circuit for measuring the back EMF induced in the stator coil of the motor following turn-off of the appliance. The frequency of the back EMF signal is determined from the zero crossings of the EMF signal. The determined frequency is then compared with a running average of previous frequency determinations, and the drive frequency of the appliance is adjusted if the difference between the compared frequencies is greater than a threshold value, e.g. 1 Hz.

Abstract: A sensorless motor control device includes a magnetic pole position estimating unit that does not use a sensor to detect a magnetic pole position of a motor having a salient rotor, and overlays a high-frequency current on the motor to estimate the magnetic pole position of the rotor of the motor; and a high-frequency current control unit for changing a magnitude of the high-frequency current based on a magnitude of one of a torque and a current of the motor.

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: An apparatus and a method for detecting a lock error in a sensorless motor are disclosed, where the apparatus includes a multiplexer, a negative booster, a comparator and a timer. The multiplexer can receive a coil voltage from the sensorless motor. The negative booster can receive a neutralizing voltage from the sensorless motor and drop the neutralizing voltage. The comparator can compare the coil voltage with the dropped neutralizing voltage for outputting a zero-crossing signal. The timer can count time duration during the zero-crossing signal maintained at the a logic level and determine the lock error in the sensorless motor when the time duration exceeds a predetermined period.

Abstract: Methods and apparatus are provided for sensorless control of a permanent magnet motor. The method includes the step of determining a sensorless position signal and a sensorless speed signal in a torque-speed plane in response to phase currents corresponding to currents on one or more of the plurality of phases.

Abstract: It makes possible to control a movable element to be smoothly movable by a sensor-less vector control in an equal speed area, without using a position sensor, and possible to perform a stop control and control it in a low speed area.

Abstract: A motor control device has first to third amplifiers which amplify voltage generated at first to third shunt resistances connected to first to third drivers to supply driving current of each of three phases to a three-phase brushless motor, first to third sample-hold circuits which sample and hold voltage amplified by the first to third amplifiers, a multiplexer which sequentially selects and outputs voltage values held by the first to third sample-hold circuits, an A/D converter which performs A/D conversion on output signals of the multiplexer, and an arithmetic unit which calculates the driving current through an output signal of the A/D converter, estimates a magnetic pole position of the motor based on the driving current, and performs pulse width modulation (PWM) control on the driving current by controlling the first to third drivers.

Abstract: [Task] A high-speed driving is possible, a utilization of a power supply having a low voltage is possible, and a regeneration is easy to be carried out. [Means to solve the task] A first buck-boost chopper portion is provided on an output side of a battery 10 to boost a voltage across battery 10 during a drive of a motor, a second buck-boost chopper portion is provided on an output side of the first buck-boost chopper portion to boost the voltage from an inverter portion 20 during a regeneration, inverter portion 20 of a 120-degree conduction current source inverter is provided on the output side of the second buck-boost chopper portion, and a motor 38 is provided on an output side of inverter portion 20.

Abstract: A sensorless starting control method for a brushless direct current (BLDC) motor, comprising a first rotor-positioning step configured to position a rotor in a first position by operating a coil unit in a first excitation state, a second rotor-positioning step configured to operate the coil unit in a second excitation state such that the rotor rotates from the first position to a second position, and an open-looped starting step configured to excite a plurality of coils of the coil unit in sequence so as to drive the rotor to rotate in a predetermined direction, wherein the coil unit generates a back electromotive force (EMF) when the rotor rotates in the predetermined direction. The method further comprises a close-looped operation step configured to control the BLDC motor to attain a predetermined rotational speed via a feedback of the back EMF.

Abstract: A bridge rectifier circuit, which takes control of a current flowing through an armature winding of a motor-generator and a battery, includes rectifier elements each made of a MOSFET; phase current detection means that detect the amount and the direction of current flowing between the drain and the source of the FET; and a control means that takes on/off control of the FET by applying a control voltage between the gate and the source thereof; wherein when the phase current detection means detect a reverse current flowing through the FET exceeding a first predetermined value, the control means applies a control voltage between the gate and the source of the FET so as to turn on the FET.

Abstract: This invention relates to the control of electrical machines and is concerned more particularly, though not exclusively, with the control of flux switching brushless permanent magnet and switched reluctance electrical machines without a mechanical shaft position sensor. Brushless Reluctance and permanent magnet motors can be used in many applications, since they do not require the use of commutators or brushes in supplying electrical power to the rotor of the motor.

Abstract: An method for driving a motor is provided. A plurality of pulse width modulation (PWM) signals are generated from a commanded voltage signal and a commanded angle signal, and these PWM signal are used to drive a motor (which has a plurality of phases). Currents through the phases of the motor are measured, and a Park transformation is performed on the measured currents to determine a projection current measurement. Based at least in part on the projection current measurement, the adjusting the commanded voltage signal and the commanded angle signal can be adjusted.

Abstract: An electric motor drive device has an inverter adjusting the voltage applied to an AC electric motor so as to drive the AC electric motor, a capacitor which is charged by a current supplied from a DC power supply supplying DC voltage between a neutral point at which a plurality of coils of the AC electric motor are connected and a positive rail or negative rail of an inverter and passing through the inverter, and a control circuit controlling the inverter so that the AC electric motor turns at a designated speed. Further, the control circuit selectively uses field weakening control and voltage boosting control for control of the inverter according to the conditions of the induced voltage generated at the AC electric motor, DC power supply, and voltage of the capacitor.

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: Provided is a sensorless BLDC motor system. The sensorless BLDC motor system includes a BLDC motor, a comparator, a motor controller, a three-phase inverter, and a mode selector. The BLDC motor includes first to third coils. The comparator compares a voltage of a specific coil of the first to third coils with a neutral-point voltage to output the compared result. The voltage of the specific coil becomes equal to the neutral-point voltage and a specific time elapses, and then the motor controller generates first and second coil control signals based on the compared result. The three-phase inverter supplies a source voltage or ground voltage to the specific coil, or floats the specific coil, in response to the first and second coil control signals. The mode selector selects a driving mode of the BLDC motor by adjusting the specific time.

Abstract: A brushless D.C. motor includes having a rotor and a plurality of stator windings that define a stator field when driven by a bridge circuit, where a microprocessor drives the bridge circuit using a pulse-width modulation logic. The brushless D.C. motor is driven by triggering a commutation of the stator field; voltage induced by rotating the rotor in a non-energized stator winding is monitored to determine whether the voltage reaches, exceeds or is below a threshold voltage. A delay time between triggering the commutation of the stator field and the voltage reaching, exceeding or being below the threshold voltage is determined; and using the determined delay time a triggering time point for a next commutation of the stator field.

Abstract: A method for operation of an internal permanent magnet motor having a rotor includes determining whether a neutral point access signal is received from the rotor and operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed derived by a first sensorless signal estimation method when the neutral point access signal is received, wherein the first sensorless signal estimation method utilizes the neutral point access signal to generate the rotor position and the rotor speed. The method further includes operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed derived by a second sensorless signal estimation method when the neutral point access signal is not received, wherein the second sensorless signal estimation method does not utilize the neutral point access signal to generate the rotor position and the rotor speed.

Abstract: A method for driving a two-phase brushless motor is disclosed. The motor includes a rotator with permanent magnetism and a stator including a first coil and a second coil. The method includes activating the two-phase brushless motor, detecting an output voltage of a disabled coil of the first coil and the second coil to generate a detection result, comparing the detection result and a reference voltage to determine a commutation time point between the first coil and the second coil, generating a commutation signal according to the commutation time point, and driving the two-phase brushless motor according to the commutation time point.

Abstract: Embodiments of the present invention permit the optimization of torque control of a permanent magnet machine including obtaining instantaneous terminal voltages of the machine, transforming the instantaneous terminal voltages to a zero direct axis voltage and a non-zero quadrature axis voltage, using a mathematical transformation, regulating the electrical frequency of the permanent-magnet machine such that the zero direct-axis voltage is adjusted to have a value of zero, determining a non-final electrical angle of the permanent-magnet machine by applying an integrator to the regulated electrical frequency of the machine, determining a final electrical angle of the of the machine by integrating the non-final electrical angle and an electrical angle from a previous calculation cycle, and regulating the current vector of the machine such that the current vector is perpendicular to the final electrical angle of the machine, thereby optimizing the torque of the machine.

Abstract: A method of aligning a sensorless brushless polyphase DC motor including aligning a rotor to a known stopped position with respect to at least one coil during a shut-down of said motor wherein a voltage is applied to one or more coils in a timed sequence of voltage application steps; and, starting said rotor from said known stopped position, wherein a voltage is applied to one or more coils in a timed sequence of voltage application steps.

Abstract: This invention provides an advanced position and velocity estimation scheme used in a position-sensorless control system for synchronous operation of an electric motor. The system includes an electric motor having a stator and a rotor; an inverter for powering the electric motor; and a controller for controlling the inverter. The controller utilizes a control system comprising a rotor angle and angular velocity estimation block; an estimated angle error detector block; a field-weakening block; and a torque-to-current converter block, all of which operate to generate control commands for operation of the motor.

Abstract: An electrical brushless motor is described, as well as a ceiling fan utilizing the electrical brushless motor.

Abstract: A controller of a multi-phase electric motor has a drive section having an upper arm switching element and a lower arm switching element for driving the multi-phase electric motor, a single current detection section for detecting a current value of the multi-phase electric motor, a pulse width modulation signal generation section for generating plural pulse width modulation of each phase within one control period based on the current value detected by the current detection section and a carrier signal, and a phase movement section for moving the pulse width modulation signal of a predetermined phase generated by the pulse width modulation signal generation section by gradually changing a movement amount of the phase in one control period, and outputting the resultant pulse width modulation signal to the drive section.

Abstract: A method and apparatus for determining electrical parameters for commissioning a sensor-less permanent magnet synchronous machine uses knowledge of the rotor position to apply balanced pulses along the rotor magnet axis and perpendicular to the rotor magnet axis allowing measurement of q- and d-inductance at multiple current levels without substantial rotor movement.

Abstract: The invention relates to methods and devices for monitoring and correcting a sensorless rotor position detection in permanently excited motors, comprising a control device and a current converter. The invention is especially characterised in that the ambiguity of the rotor position determined from the inductance ratios of the motor, in permanently excited motors, can be resolved in a simple manner without a sensor, and a defectively determined angle can be corrected as required. To this end, during the operation of the motor, the rotor position is detected by means of an inductance-based detection device. Furthermore, the rotor position is monitored in relation to the ambiguity of the inductance-based signals by means of a monitoring/correcting device, and where necessary, an occurring angle error corrected, the currents in the motor being modified.