Abstract: A zero-cross detection unit monitors an AC voltage detected by a voltage sensor, generates a zero-cross point signal when the voltage crosses 0V, and supplies the signal to a controller. A rotation number setting unit sets a rotation number command to serve as a target of a synchronous motor. A rotation number correction coefficient data table stores correction coefficient data for a target rotation number. A correction coefficient data extraction unit extracts correction coefficient data in accordance with an elapsed time of the zero-cross point signal generated by the zero-cross detection unit from a rotation number correction coefficient data table, and outputs the data to a corrected rotation number creation unit. The corrected rotation number creation unit corrects the rotation number set by the rotation number setting unit in accordance with the extracted correction coefficient data, and outputs the corrected rotation number to a sine wave data creation unit.

Abstract: A driving apparatus of a sensorless brushless motor includes an inverter circuit supplying a power supply voltage to three phase terminals of three phase armature windings of the sensorless brushless motor provided with a stator and with a rotor including a pair of magnetic poles, a PWM generator circuit generating a pulse-width modulation signal, a position detection circuit operating at a particular phase of the pulse-width modulation signal, detecting an induced voltage induced at the terminal that is in a non-energization time zone and detecting a rotational position of the rotor, an inverter control circuit determining an energization time zone and transmitting an energization control signal to the inverter circuit, and a PWM delay circuit generating a pulse-width modulation signal for position detection by delaying the pulse-width modulation signal, wherein the position detection circuit operates at a particular phase of the pulse-width modulation signal for position detection.

Abstract: Provided is a motor driving apparatus including a motor drive unit including a plurality of transistors which are repeatedly turned on and off in response to a pulse having a pulse width modulated at a first carrier frequency to control driving of a motor in a normal operation state and which supply a drive current to the motor; and a control unit that controls the plurality of transistors to be turned on and off in response to a pulse having a pulse width modulated at a second carrier frequency higher than the first carrier frequency, when a voltage applied between input terminals of the motor drive unit rises to a predetermined value.

Abstract: An inverter controller for driving a brushless DC motor, of which rotor is provided with permanent magnets, includes an inverter circuit, a position sensing circuit, a DC voltage sensor, and a conduction angle controller. The inverter circuit is connected to the brushless DC motor for driving this motor. The position sensing circuit senses a rotor position with respect to a stator from an induction voltage of the brushless DC motor. The DC voltage sensor senses a voltage value of a DC power voltage supplied to the inverter circuit. The conduction angle controller changes a conduction angle of the inverter circuit within a range less than 180 degrees in electric angles in response to a rate of change in the DC power voltage.

Abstract: A power conversion device includes an inverter unit and a control unit. The inverter unit includes high SWs and low SWs for each phase of coils of a motor. The control unit, in a case that the on-time of the high SWs and the low SWs is shorter than a predetermined time determined based on a dead time, changes an output voltage average value such that the on-time of the high SWs or the on-time of the low SWs becomes longer than the predetermined time. The voltage use rate can be improved without disposing a special circuit, and distortion of inter-line voltages or distortion of currents can be suppressed.

Abstract: The rotation period of a motor is subdivided by edge interval times and a rate of change between a currently calculated edge interval time and an edge interval time calculated one rotation of the motor previously is calculated at the detection of each edge. Then the rotation period of the motor is calculated by multiplying a set reference period by the calculated rate of change.

Abstract: The present invention discloses a controller and a method for adaptively adjusting motor driving current waveforms. According to the present invention, the controller receives multiple different control parameters which may be determined according to the characteristics of a fan to be controlled, and adjusts the delayed ON time and advanced OFF time of a PWM driving signal based on the control parameters and the present rotation speed of the fan motor, so that the fan operates under an optimum driving current waveform.

Abstract: PWM conversion is efficiently executed. An output control circuit comprises a flip-flop which reads crossing of a reference value by a rotational state signal from a motor, and generates a motor drive control signal according to a state of the flip-flop. A clock generator generates a clock which defines a time of reading data in the flip-flop of the output control circuit. A PWM conversion circuit PWM-converts the drive control signal using the clock as a PWM signal.

Abstract: A method of controlling an electrical machine that includes commutating a phase winding of the electrical machine at a time T_COM(1) after a first edge and at a time T_COM(2) after a second edge of a rotor-position signal. T_COM(2) is defined by the equation: T_COM(2)=T_COM(1)+T_AVE?T_PD, where T_AVE is an average period between edges of the rotor-position signal, and T_PD is the period between the first and second edges. Additionally, a controller and control system that implement the method.

Abstract: A method for starting a brushless DC motor. A rotor is aligned with a stator in accordance with a predetermined phase. After alignment, the rotor is positioned in accordance with another phase, two phases are skipped, a timer is set to a first count time, and the rotor is aligned with the stator in accordance with a third phase. Then the timer is restarted and the rotor is aligned with the stator in accordance with a fourth phase. After a first delay, first back electromotive force value is stored. The timer is stopped when the first back electromotive force value substantially equals a peak amplitude of opposite polarity. The timer is updated to a second count time that is substantially equal to a time at which the second timer was stopped. The process is repeated until the rotor has a position and a velocity that are suitable for normal operation.

Abstract: A motor driving device driving coil terminals of a three-phase motor to flow three-phase currents includes: a pulse modulator generating three-phase modulation pulses, each of which has a duty ratio in accordance with a voltage level of a coil terminal; a shift amount selection unit selecting a first shift amount corresponding to at least one of two predetermined amounts according to a pulse width of the longest pulse among the three-phase modulation pulses; a first shift unit shifting the second-longest pulse among the three-phase modulation pulses backward by the first shift amount to delay timing; a second shift unit shifting the third-longest pulse among the three-phase modulation pulses backward by a predetermined second shift amount to delay timing; and an inverter driving each of the coil terminals by switching a driving power supply with the three-phase modulation pulses by reflecting shift results of the first and second shift units.

Abstract: A brushless D.C. disk motor has one or more disk rotor assemblies and pairs of stator assemblies for each rotor assembly. Each disk rotor assembly has a disk and a plurality of permanent magnets distributed along two or more circular paths in the disk inboard of the peripheral edge of the rotor. Each stator assembly has a plurality of pole pieces and coils distributed along a mounting plate in corresponding circular paths. The disk is rotatably mounted to a support member; while the stator sub-assemblies are fixed to the support member. The coils are selectively activated by commutated power control signals generated in response to a vehicle condition parameter, such as vehicle speed or disk motor load, to optimize power drain from the source of electrical power in accordance with the value of the vehicle condition parameter.

Abstract: Systems and methods are provided for pulse-width modulated control of power inverter using phase-shifted carrier signals. An electrical system comprises an energy source and a motor. The motor has a first set of windings and a second set of windings, which are electrically isolated from each other. An inverter module is coupled between the energy source and the motor and comprises a first set of phase legs coupled to the first set of windings and a second set of phase legs coupled to the second set of windings. A controller is coupled to the inverter module and is configured to achieve a desired power flow between the energy source and the motor by modulating the first set of phase legs using a first carrier signal and modulating the second set of phase legs using a second carrier signal. The second carrier signal is phase-shifted relative to the first carrier signal.

Abstract: A brushless motor drive circuit has a first AD converter which converts a voltage value depending upon a power supply voltage supplied from a power supply to drive a three-phase brushless motor, to a digital signal and outputs the digital signal. The brushless motor drive circuit has an energization timing adjustment circuit which outputs an adjustment signal for adjusting a lead angle value or a lag angle value of energization timing of the three-phase brushless motor, in response to the digital signal which is output by the first AD converter. The brushless motor drive circuit has an energization timing setting circuit which sets the energization timing of the three-phase brushless motor.

Abstract: A control circuit controls an electric motor and includes: a measuring device configured to measure a first phase current of the motor and provide a corresponding first analog signal; an analog-to-digital converter structured to convert the first analog signal into a first digital signal; a conversion module for generating a first converted digital signal representative of the first digital signal expressed in a rotating reference system; a node structured to compare the first converted digital signal into a first reference signal and generate a first error signal; and a measure control circuit structured to provide a timing signal of the analog-to-digital converter depending on the first error signal and a time delay introduced by the measuring device.

Abstract: In a method and apparatus for calibrating a position sensor mounted on the shaft of a permanent magnet synchronous motor, to control the position of a rotor of the permanent magnet synchronous motor relative to a magnetic field produced by a stator of the permanent magnet synchronous motor, a DC test current is supplied to stator windings of the permanent magnet synchronous motor to generate a definite magnetic field. The motor speed caused by the DC test current is adjusted to zero by modifying the rotor position; and the position measured by the position sensor at zero motor speed relative to the magnetic field is used to calibrate the position sensor.

Abstract: In the motor drive apparatus, a Hall element outputs a first sinusoidal signal and a second sinusoidal signal, of mutually opposite phases, in accordance with rotor position. A hysteresis comparator compares the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a rectangular wave signal. A pulse width modulation signal generation circuit detects timing at which phase switches, based on the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a pulse width modulation signal in which duty ratio gradually changes, in a predetermined time-period in which the phase switches. A drive circuit combines the rectangular wave signal and the pulse width modulation signal by a logical operation, and drives the fan motor.

Abstract: An energization signal generating circuit respectively compares back electromotive forces generated in coils of each phase of a motor with a midpoint voltage of each phase, and generates energization signals. A pulse signal generating circuit generates a pulse signal in which duty ratio is controlled according to torque. A ramp signal generating circuit divides, into a plurality of times, a period of a frequency generation signal obtained by synthesizing the energization signals, and, for each divided time unit, generates a ramp signal in which pulse width gradually changes, and which has a frequency the same as the pulse signal. An output circuit supplies a drive current to the coils of each phase, based on the energization signals, the pulse signal, and the ramp signal.

Abstract: A motor controller is provided. The motor controller includes a motor drive unit that drives a plurality of motors; a thermal shutdown unit that is provided in the motor drive unit and that stops the plurality of motors in the case of an overload; a lock signal generation unit that generates a lock signal corresponding to a respective one of the plurality of motors when a rotational speed of the respective motor reaches a threshold speed set for the respective motor; and an operation determination unit which, when the lock signal generation unit interrupts lock signals for all of the plurality of motors, determines that thermal shutdown unit has operated.

Abstract: A motor control device has a three-phase bridge circuit, a driving circuit, and a microcomputer. The three-phase bridge circuit has three pairs of MOSFETs for U, V, and W phases of a three-phase AC motor as a control target. The microcomputer has a dead time set value storage unit and a PWM signal generation unit. The PWM signal generation unit generates a PWM signal with a dead time including a response characteristics of the pair of MOSFETs for each of U, V, and W phases of the AC motor based on a three-phase voltage instruction value supplied from an outside device and the dead time set value stored in the dead time set value storage unit. The PWM signal generation unit outputs the PWM signal for each phase to the driving circuit. This independently adjusts the dead time for the MOSFETs for each phase.

Abstract: Circuitry for controlling a motor, such as a brushless motor (BLM), is disclosed. The circuitry may comprise one or more inputs for receiving rotor position signals from one or more Hall effect sensors that detect the position of, for example, a BLM rotor. The circuitry may also comprise an input for receiving a pulse width modulated speed control signal. The circuitry generates one or more drive signals, each drive signal having a plurality of driving intervals. Each drive signal may control power switches during its driving intervals, the power switches being coupled to electromagnets of the BLM. The circuitry may cause the driving intervals of a first drive signal to be temporally spaced from the driving intervals of a second drive signal.

Abstract: An apparatus for estimating rotor position for brushless motors capable of accurately estimating rotor position even though power source voltage fluctuates is provided. First, the power source voltage is detected, and voltage is supplied only for a certain period of time and a current response is detected. The current detection value is multiplied by the ratio of a reference voltage to the power source voltage detected to correct the current detection value. Specifically, the peak current detection value is corrected upwardly or downwardly in each direction. A voltage supplying direction in which the current detection value is maximized is searched for to estimate the rotor position and a brushless motor is started.

Abstract: A drive system for a motor has a switching network for supplying three phases of power to a motor, and a control for the switching network. The control is programmed to provide a commutation with a positive offset, ahead of a current position, when driving in opposition to a load, and to use one of a zero or negative offset when the control drives the motor complementary to the load force. A method and system are also disclosed and claimed.

Abstract: An apparatus for estimating rotor position for brushless motors capable of accurately estimating rotor position is provided. The apparatus may be used as a start-up system for brushless motors. The apparatus performs accurate estimation even though power source voltage fluctuates, and is able to provide compact configuration. The apparatus supplies voltage to the coils respectively. In each supplying period, the apparatus counts voltage supply period of time until current value reaches to a current threshold value. Since a coil indicative of rotor stop position is prone to be magnetically saturated. The apparatus estimates the rotor stop position based on the voltage supply periods. Then, the apparatus starts a switching sequence based on the rotor stop position.

Abstract: A method of preventing concurrent or quasi-concurrent commutations of a pair of phase shift modulation (PSM) drive signals of an output bridge stage driving an electrical load includes establishing a threshold level of a programmed current level to be transmitted though the electrical load. The method also includes, if the programmed current level is lower than the threshold level, enhancing a time offset between commutation edges of the pair of PSM drive signals by a minimum time.

Abstract: The drive control circuit for an electric motor is provided. The drive control circuit includes: an original drive signal generator that generates an original drive signal; an excitation interval setter that is able, for each half cycle of respective length ? in each 2? excitation cycle of the original drive signal, to arbitrarily set excitation intervals during which to excite coils of the electric motor to any one of a plurality of intervals which include at least either one of a symmetrical interval centered on a center of each half-cycle and an unsymmetrical interval; and a drive signal shaping circuit that generates a drive signal for driving the electric motor, by validating the original drive signal during the excitation intervals and invalidating the original drive signal during non-excitation intervals other than the excitation interval.

Abstract: A method of controlling a brushless motor that includes rectifying an alternating voltage to provide a rectified voltage, and exciting a winding of the motor with the rectified voltage. The winding is excited in advance of predetermined rotor positions by an advance period that is updated in response to a zero-crossing in the alternating voltage. Additionally, a control system that implements the method, and a motor system that incorporates the control system.

Abstract: A method of controlling a brushless motor that includes rectifying an alternating voltage to provide a rectified voltage, exciting a winding of the motor with the rectified voltage for a conduction period over each electrical half-cycle of the motor, and updating the conduction period in response to a zero-crossing in the alternating voltage. Additionally, a control system that implements the method, and a motor system that incorporates the control system.

Abstract: A method of controlling a brushless motor that includes rectifying an alternating voltage to provide a rectified voltage, exciting a winding of the motor with the rectified voltage and freewheeling the winding when current in the winding exceeds a threshold. The winding is freewheeled for a freewheel period, which is updated in response to a zero-crossing in the alternating voltage. Additionally, a control system that implements the method, and a motor system that incorporates the control system.

Abstract: A method of controlling a brushless motor that includes exciting a winding of the motor with a voltage, and freewheeling the winding when current in the winding exceeds a threshold or after the winding has been excited for a timeout period. The timeout period is adjusted in response to a change in one of the voltage and the motor speed. Additionally, a control system that implements the method, and a motor system that incorporates the control system.

Abstract: A controller for a brushless motor that includes an input for receiving an analog signal, an analog-to-digital converter (ADC) for sampling the analog signal, and a processor. The processor starts the ADC during a first electrical half-cycle and reads the ADC during a second electrical half-cycle of the motor. Additionally, a motor system that includes the controller.

Abstract: The method of synchronizing sequential phase switchings in driving stator windings of a multiphase sensorless brushless motor with a reconstructed information on the current angular position of a permanent magnet rotor, includes sampling on a currently non-conductive stator winding a voltage induced thereon by the resultant magnetic field produced by the drive current forced through currently conductive stator windings that inverts its sign when the rotor transitions across a plurality of significant angular positions, at which orthogonality between the resultant magnetic field and a magnetic axis of the non-excited winding verifies.

Abstract: A motor and a motor speed control system are disclosed. Two power signal lines and one feedback/speed-control signal line are coupled between a control device and the motor. The two power signal lines electrically connect the control device to the motor. The feedback/speed-control signal line bi-directionally transmits signals coming from the control device to the motor and from the motor to the control device.

Abstract: The invention specifies a circuit arrangement (1, 20) for controlling a brushless electric motor (37) with a control chip (2), particularly a microcontroller, which has a number of PWM contacts (8), which can be used to output a PWM signal, and a number of commutation contacts (5,5?, 6,6?, 7,7?), which can be used to output a commutation signal. In this case, provision is made for at least one commutation contact (5,5?, 6,6?, 7,7?) to be alternately controllable as an input and an output, for the at least one commutation contact (5,5?, 6,6?, 7,7?) to have its output electrically connected to a PWM contact (8), and for the commutation contact (5,5?, 6,6?, 7,7?) connected in this manner to be able to be contacted for the purpose of tapping off a control signal. Such a circuit arrangement (1,20) increases the control options for a given control chip (2). The number of PWM sources required is reduced.

Abstract: A brushless DC motor driving system, in which the duty cycle of the PWM control signals for the duty cycle generator is determined by a speed control circuit, a feedback comparator, and the set and reset signals of a S-R Flip-Flop, wherein the PWM control signals pass through the Hall synthesis circuit, the logic control circuit to drive the coil by the drive current generated, and the duty cycle of the PWM control signals is further adjusted by means of the feedback sensing voltage obtained from the driving current and sensing resistance and fed back to the feedback comparator, the stability and linear stability of the input voltage and the driving current being achieved.

Abstract: Methods, systems and computer program products for compensating repeatable timing variations associated with a spindle motor are described. Specifically, a repetitive error correction factor may be determined using a computational model which predicts timing variations. The correction factor can then be used to cancel the effect of the actual timing variations upon the spindle motor.

Abstract: A motor includes a rotor having a magnet, a stator having two coils, and a controller configured to control excitations of the two coils. The stator includes first and second yokes excited by the coils, and first and second rotor detectors configured to detect a magnetic flux. The first yoke is arranged for each electric angle of 360°, and the second yoke shifts from the first yoke by an electric angle of 90°. The first rotor position detector is arranged at the same position as the first yoke. The controller generates an excitation switching signal for each coil based on detection signals from the first and second rotor position detectors, and excites a corresponding coil, and obtains first and second delay angles.

Abstract: An energization timing determination circuit corrects a shift contained in a position signal outputted from a position detecting means and supplies energization timing appropriate to drive a motor. A correction amount computation unit computes detection intervals obtained based on position signals outputted from filters, comparators, and a position detection unit during one cycle of electrical angle. The correction amount computation unit thereby determines the duty shift length ? and phase shift length ? of the position signals. A control circuit corrects energization timing based on the position signals according to the detected shift lengths.

Abstract: A drive motor control apparatus for a vehicle, wherein the vehicle has a motor and rotation detecting unit. In the apparatus, the first difference computing unit computes one of multiple first differences every time an actual detected angle of rotation of the motor becomes a corresponding representative angle during the one cycle. The first difference indicates an advancing amount of an estimated angle relative to the actual detected angle. The second difference computing unit computes multiple second differences based on the first differences of the one cycle. The second differences are adjusted in accordance with a degree of acceleration and deceleration of the motor. The adjusted second differences are used for correcting the actual detected angle of rotation of the motor.

Abstract: The circuit structured to drive a motor is provided. The circuit includes: a division signal generator that generates a division signal dividing each of a high level period and a low level period of a binary position signal representing a relative position of a magnetic coil to a permanent magnet into a preset number of multiple divisions; a pulse width setter that sets a pulse width for PWM control corresponding to each of the multiple divisions represented by the division signal; and a PWM signal generator that performs PWM control with the set pulse width, thereby generating a PWM signal as a driving signal for driving the motor.

Abstract: A motor control device includes a sensing circuit, a phase-shifting circuit, a comparing circuit and a control circuit. The sensing circuit senses the motor to generate a sensing signal. The phase-shifting circuit is electrically connected to the sensing circuit and receives the sensing signal to generate a phase-shifting signal. The comparing circuit is electrically connected to the phase-shifting circuit and receives the phase-shifting signal to generate a comparing signal. The control circuit is electrically connected with the comparing circuit and the motor, and receives the comparing signal to generate a control signal so as to control the rotation speed of the motor.

Abstract: A commutation circuit for driving a brushless DC motor is controlled according to a commutation cycle composed of alternating primary steps and transitional steps. The commutation circuit includes pairs of field effect transistors coupled in series between the high voltage and low voltage terminals of a DC power supply. Output terminals between each pair of transistors are individually coupled to the phases of a DC motor. A controller operates the commutation circuit to selectively set the phases at active and inactive states. The controller further employs a plurality of voltage control functions individually associated with the motor phases to selectively modulate the voltage applied to one of the phases during the active states, to provide transitional steps in the commutation cycle during which the applied voltage is modulated to reduce its magnitude with respect to the high voltage or the low voltage.

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: In the motor drive apparatus, a Hall element outputs a first sinusoidal signal and a second sinusoidal signal, of mutually opposite phases, in accordance with rotor position. A hysteresis comparator compares the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a rectangular wave signal. A pulse width modulation signal generation circuit detects timing at which phase switches, based on the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a pulse width modulation signal in which duty ratio gradually changes, in a predetermined time-period in which the phase switches. A drive circuit combines the rectangular wave signal and the pulse width modulation signal by a logical operation, and drives the fan motor.

Abstract: Embodiments of the invention provide a method of operating a motor connected to a power device having a reduced current rating. The motor can include an increased torque constant and/or an increased back electromagnetic force constant in order to decrease a peak current in relation to the reduced current rating of the power device. The method can include increasing a length of time the motor can operate at the peak current without overheating. A phase angle of the motor can be advanced in order to achieve a continuous operating point with the power device having the reduced current rating.

Abstract: A motor control apparatus includes a phase sensing circuit, a current sensing circuit, a controller and a driving circuit. The driving circuit receives a first driving signal and then controls a phase switching state of the magnetic pole of the motor so as to drive the motor in accordance with the first driving signal. The phase sensing circuit detects the phase switching state of the magnetic pole to generate and output a phase switching signal to the controller during the motor is operating. The current sensing circuit detects a current flowing through the motor to generate and output a current phase signal to the controller. The controller compares a phase difference between the phase switching signal and the current phase signal to generate and output a second driving signal to the driving circuit. The driving circuit controls the phase switching state of the magnetic pole for driving the motor in accordance with the second driving signal.

Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.

Abstract: A compact field programmable gate array (FPGA)-based digital motor controller (102), a method, and a design structure are provided. The compact FPGA-based digital motor controller (102) includes a sensor interface (206) configured to receive sensor data from one or more sensors (104) and generate conditioned sensor data. The one or more sensors (104) provide position information for a DC brushless motor (108). The compact FPGA-based digital motor controller (102) also includes a commutation control (210) configured to create switching commands to control commutation for the DC brushless motor (108). The commutation control (210) generates commutation pulses from the conditioned sensor data of the sensor interface (206). The compact FPGA-based digital motor controller (102) also includes a time inverter (208) configured to receive the commutation pulses.

Abstract: A method of tuning a DC brushless motor, wherein measurement of back EMF voltage is used to detect changes in the torque requirements caused by variation in the operating conditions of the DC brushless motor, the method including varying the timing of the driving signals to the motor to compensate for the changes in the torque requirements.

Abstract: The present invention provides an improved current regulator for PWM based drives for electric motors. The invention provides compensation for the rotor position signal for delays introduced due to the PWM algorithm and for digital sampling present in such a drive. Current regulator commonly operate in a two-phase reference frame, requiring forward and reverse coordinate transformations between the physical current values and the two-phase reference frame variables. The present invention provides an improved compensation in the forward transformation by determining the phase lag between the commanded voltage reference and the output voltage reference and by further compensating the forward transformation for errors introduced due to sampling the current either at different sampling instances than the rotor position or at multiple sampling instances during a carrier period.