TWI500253B - Method and electronic circuit for driving a multi-phase motor having a plurality of motor windings - Google Patents

Description

Method and electronic circuit for driving multi-phase motor with multiple motor windings

The present invention relates generally to electric motor control circuits, and more particularly to electric motor control circuits that provide automatic adjustment of the phase of the drive signal applied to the electric motor and that can detect zero current in the windings of the electric motor.

Circuitry for controlling and driving a brushless DC (BLDC) electric motor is known. In several configurations, the circuit provides a phase lead in driving the drive signal of the electric motor, the phase lead being related to the rotational speed of the electric motor or the total motor current being measured. However, such circuits can only provide one or a few relationships between phase lead and rotational speed. In addition, the external components and pins of the motor control integrated circuit (IC) may need to set parameters for each of the electric motors or each of the electric motor applications.

Several known electric motor drive circuits were available in September 2009 U.S. Patent No. 7, 590, 334, issued on Dec. 5, and U.S. Patent No. 7, 747, 146, issued on Jun. The manner in which it is mentioned is incorporated herein by reference.

When BLDC electric motors are used in different applications, different efficiency behaviors relative to speed can be exhibited. For example, the same BLDC electric motor can use different blade configurations for different applications. Different types of BLDC electric motors can also exhibit different efficiency behaviors relative to speed.

Motor noise, vibration, and efficiency are affected by various characteristics. One such characteristic is the current phase, which occurs in the motor winding relative to the rotational position of the motor. In particular, as the motor speed increases or decreases, the phase of the current can lag behind or lead the reference rotational position of the motor. Moreover, at high motor speeds, the current in the motor windings tends to lag behind the motor's reference position.

In view of the above, it is desirable to provide an electric motor control circuit and associated method for generating an electric motor drive signal having an automatic phase adjustment determined based on a detected phase difference between a motor winding current and a motor rotational position.

In view of the above, it is also desirable to provide an electric motor control circuit and associated method for detecting the phase of the current in the motor winding, for example, by detecting a zero crossing of the current.

The present invention provides an electric motor control circuit and associated method that produces an electric motor drive signal having an automatic phase adjustment determined based on a detected phase difference between a motor winding current and a motor rotational position.

The present invention also provides an electric motor control circuit and associated method that can detect the phase of the current in the motor winding, for example, by detecting a zero crossing of the current.

According to one aspect of the invention, a method of driving a multi-phase motor having a plurality of motor windings includes generating a zero current signal indicative of a zero crossing of current through at least one of the plurality of motor windings; generating an angle indicative of the motor a position reference signal of the rotated reference position; comparing a phase of the zero current signal with a phase of the position reference signal to generate a phase comparison signal; generating a plurality of modulated signals, each having a phase relating to a value of the phase comparison signal; A plurality of motor drive signals to the plurality of motor windings are generated based on the complex modulation signal.

In several embodiments, the above methods can include one or more of the following aspects.

In some embodiments of the method, the generating the position reference signal includes generating a Hall sensor signal with a Hall sensor configured to access the motor.

In some embodiments of the method, the generating the position reference signal comprises: A post EMF signal is generated by a post electromotive force (EMF) module coupled to at least one of the plurality of motor windings.

In some embodiments of the method, the generating the position reference signal includes: stopping a motor drive signal to at least one of the plurality of motor windings during a time window of the motor proximate to the reference position; and The zero crossing of the EMF signal detects the reference position during the time window.

In some embodiments of the method, the generating the complex modulation signal includes: providing a lookup table, wherein the modulation value is stored corresponding to a shape of at least one of the complex modulation signals; generating a minimum value and a maximum value And a first continuous sawtooth ramp signal between the minimum value and the maximum value; adding a value related to the phase comparison signal to the first continuous sawtooth ramp signal to generate the minimum value and the maximum value And the complex value of the second continuous sawtooth ramp signal between the minimum value and the maximum value, wherein the minimum value and the maximum value of the second continuous sawtooth ramp signal are from the first continuous sawtooth ramp wave Offseting the minimum value of the signal and the adjustment time of the maximum value, wherein the adjustment time is related to the phase comparison signal; using the adjusted continuous sawtooth ramp signal to successively search for values in the lookup table to generate At least one of the complex modulated signals; and generating at least one other modulated signal in a predetermined phase relationship relative to the at least one of the complex modulated signals.

In some embodiments of the method, the generating the zero current signal comprises: generating the plurality of motor drive signals by a plurality of individual half bridge circuits coupled to the electric motor, each half bridge circuit comprising: an individual first and second series coupling a power supply crystal; an individual power supply high voltage node for receiving a high power supply voltage; an individual power supply low voltage node for receiving a low power supply voltage; and an individual output node for generating an individual one of the plurality of motor drive signals; Passing a reverse current of at least one of the first transistor or the second transistor of at least one of the plurality of half bridge circuits, wherein the detecting comprises at least one of: detecting at the output node is higher than a voltage of the high supply voltage; or detecting a voltage lower than the low supply voltage at the output node; and generating a zero crossing of the indication current despite detecting the reverse current, at least one of the plurality of motor windings Zero current signal.

In some embodiments of the method, the detecting the reverse current comprises: detecting the reverse current by sampling a voltage of the output node only when the first transistor and the second transistor are both off.

In some embodiments of the method, each of the plurality of motor drive signals comprises: Individual complex pulse width modulation signals, each of the complex pulse width signals having a high state including a steady state high value close to the high power supply voltage and a transient high value higher than the higher power supply voltage, and the complex pulse Each of the width signals also has a low state comprising a steady state low value proximate to the low supply voltage and a transient low value below the lower supply voltage.

In accordance with another aspect of the present invention, an electronic circuit for driving a multi-phase motor having a plurality of motor windings includes a current measurement module that is assembled to generate a zero current signal indicative of passing the plurality A zero crossing of the current of at least one of the motor windings. The electronic circuit also includes a position measuring module that is configured to generate a position reference signal indicative of a reference position of the angular rotation of the motor. The electronic circuit also includes a modulated signal generating module configured to compare the phase of the zero current signal with the phase of the position reference signal to generate a phase comparison signal, and is configured to generate a complex modulated signal, each of which There is a phase related to the value of the phase comparison signal. The electronic circuit also includes a drive circuit configured to generate a plurality of motor drive signals to the plurality of motor windings based on the complex modulation signal.

In several embodiments, the above electronic circuitry can include one or more of the following aspects.

In some embodiments of the electronic circuit, the position measuring module is further configured to generate the position signal based on a Hall signal generated by configuring a Hall sensor proximate the motor.

In some embodiments of the electronic circuit, the position measuring module is further configured to generate the position signal based on a post EMF signal generated in the motor winding.

In some embodiments of the electronic circuit, the generating the position reference signal includes: stopping a motor drive signal to at least one of the plurality of motor windings during a time window of the motor proximate to the reference position; The zero crossing of the back EMF signal detects the reference position during the time window.

In some embodiments of the electronic circuit, the modulation signal generating module includes: a lookup table, wherein the modulation value is stored corresponding to the shape of at least one of the complex modulation signals; the sawtooth generator is assembled Generating a first continuous sawtooth ramp signal having a minimum value and a maximum value and a complex value between the minimum value and the maximum value; a timing/phase error detector coupled to receive a signal representative of the zero current signal, coupled Receiving a signal representative of the position reference signal and combining to generate a signal representative of the phase comparison signal; and a summation module configured to increase a value of the phase comparison signal to the first continuous sawtooth skew a second continuous sawtooth ramp signal having the minimum value and the maximum value and the complex value between the minimum value and the maximum value, wherein the minimum value of the second continuous sawtooth ramp signal is The maximum value is offset in time by the minimum value of the first continuous sawtooth ramp signal and the adjustment time of the maximum value, wherein the adjustment time is related to the phase comparison signal, wherein The adjusted continuous sawtooth ramp signal is used to successively search for values in the lookup table to generate the at least one of the complex modulated signals, and also to use the at least one of the complex modulated signals The predetermined phase relationship of the person produces at least one other modulated signal.

In some embodiments, the electronic circuit further includes: a plurality of half bridge circuits coupled to the electric motor, configured to generate the plurality of motor drive signals, each half bridge circuit comprising: an individual first and second series coupling a power supply crystal; an individual power supply high voltage node for receiving a high power supply voltage; an individual power supply low voltage node for receiving a low power supply voltage; and an individual output node for generating an individual one of the plurality of motor drive signals; at least one a comparator configured to generate, by detecting, at least one comparator that indicates a reverse current through at least one of the first transistor or the second transistor of at least one of the plurality of half bridge circuits An output signal, the detection comprising at least one of: a voltage at the output node that is higher than the high supply voltage; or a voltage at the output node that is lower than the low supply voltage; and a processor configured to The at least one comparator output signal, although at least one of the plurality of motor windings, produces the zero current signal indicative of the zero crossing of the current.

In some embodiments of the electronic circuit, the detecting includes detecting the reverse current by sampling a voltage of the output node only when the first transistor and the second transistor are both off.

In some embodiments of the electronic circuit, each of the plurality of motor drive signals comprises: Individual complex pulse width modulation signals, each of the complex pulse width signals having a high state including a steady state high value close to the high power supply voltage and a transient high value higher than the higher power supply voltage, and the complex pulse Each of the width signals also has a low state comprising a steady state low value proximate to the low supply voltage and a transient low value below the lower supply voltage.

In accordance with another aspect of the present invention, a method of driving a multi-phase motor having a plurality of motor windings includes generating a motor drive signal with a half bridge circuit coupled to the electric motor. The half bridge circuit includes first and second series of coupled transistors; a power supply high voltage node for receiving a high power supply voltage; a power supply low voltage node for receiving a low power supply voltage; and an output node for generating the complex motor Drive signal. The method also includes detecting a reverse current through at least one of the first transistor or the second transistor. The detecting includes at least one of: detecting a voltage higher than the high power supply voltage at the output node; or detecting a voltage lower than the low power supply voltage at the output node. The method also includes generating a zero current signal based on the detecting the reverse current indicative of a zero crossing of current through at least one of the plurality of motor windings.

In several embodiments, the above methods may include one or more of the following aspects.

In some embodiments of the method, the detecting the reverse current comprises: detecting the reverse current by sampling a voltage of the output node only when the first transistor and the second transistor are both off.

In several embodiments of the method, the motor drive signal package And comprising: a plurality of pulse width modulation signals, each of the complex pulse width signals having a high state including a steady state high value close to the high power supply voltage and a transient high value higher than the higher power supply voltage, and the complex number Each of the pulse width signals also has a low state comprising a steady state low value proximate to the low supply voltage and a transient low value below the lower supply voltage.

In some embodiments, the method further comprises: generating a position reference signal indicative of a reference position of the angular rotation of the motor; comparing a phase of the zero current signal with a phase of the position reference signal to generate a phase comparison signal; generating a complex modulation Signals, each having a phase relating to a value of the phase comparison signal; and generating a plurality of motor drive signals to the plurality of motor windings based on the complex modulation signal.

In some embodiments of the method, the generating the position reference signal includes generating a Hall sensor signal with a Hall sensor configured to access the motor.

In some embodiments of the method, the generating the position reference signal includes generating a rear EMF signal with a post electromotive force (EMF) module coupled to at least one of the plurality of motor windings.

In several embodiments of the method, the generating the position reference The signal includes: stopping a motor drive signal to the at least one of the plurality of motor windings during a time window of the motor proximate to the reference position; and detecting the time window during a zero crossing of the rear EMF signal The reference location.

In some embodiments of the method, the generating the complex modulation signal includes: providing a lookup table, wherein the modulation value is stored corresponding to a shape of at least one of the complex modulation signals; generating a minimum value and a maximum value And a first continuous sawtooth ramp signal between the minimum value and the maximum value; adding a value related to the phase comparison signal to the first continuous sawtooth ramp signal to generate the minimum value and the maximum value And the complex value of the second continuous sawtooth ramp signal between the minimum value and the maximum value, wherein the minimum value and the maximum value of the second continuous sawtooth ramp signal are from the first continuous sawtooth ramp wave Offseting the minimum value of the signal and the adjustment time of the maximum value, wherein the adjustment time is related to the phase comparison signal; using the adjusted continuous sawtooth ramp signal to successively search for values in the lookup table to generate At least one of the complex modulated signals; and generating at least one other modulated signal in a predetermined phase relationship relative to the at least one of the complex modulated signals, each modulated signal For an individual one of the plurality of pulse width modulation (PWM) signals.

In accordance with another aspect of the present invention, an electronic circuit for driving a multi-phase motor having a plurality of motor windings includes generating a motor The drive signal is coupled to the half bridge circuit of the electric motor. The half bridge circuit includes first and second series of coupled transistors; a power supply high voltage node for receiving a high power supply voltage; a power supply low voltage node for receiving a low power supply voltage; and an output node for generating the motor drive signal. The electronic circuit also includes at least one comparator configured to generate at least one comparator output signal indicative of a reverse current through at least one of the first transistor or the second transistor by detection, The detecting includes at least one of: a voltage at the output node that is higher than the high supply voltage; or a voltage at the output node that is lower than the low supply voltage. The electronic circuit also includes a processor configured to generate a zero current signal indicative of a zero crossing of current through at least one of the plurality of motor windings based on the at least one comparator output signal.

In several embodiments, the above electronic circuitry can include one or more of the following aspects.

In some embodiments of the electronic circuit, the detecting includes detecting the reverse current by sampling a voltage of the output node only when the first transistor and the second transistor are both off.

In some embodiments of the electronic circuit, the motor drive signal includes: a plurality of pulse width modulation signals, each of the plurality of pulse width signals having a steady state high value close to the high power supply voltage and higher than the higher power supply The transient state of the voltage is high, and each of the complex pulse width signals also has a low state comprising a steady state low value close to the low supply voltage and a transient low value lower than the lower supply voltage.

In some embodiments, the electronic circuit further includes: a position measuring module configured to generate a position reference signal indicating a reference position of the angular rotation of the motor; and a modulation signal generating module configured to compare the The phase of the zero current signal is phased with the position reference signal to produce a phase comparison signal and is combined to produce a complex modulated signal, each having a phase relating to the value of the phase comparison signal.

In some embodiments of the electronic circuit, the position measuring module is further configured to generate the position signal based on a Hall signal generated by configuring a Hall sensor proximate the motor.

In some embodiments of the electronic circuit, the position measuring module is further configured to generate the position signal based on a post EMF signal generated in the motor winding.

In some embodiments of the electronic circuit, the electronic circuit is configured to stop a motor drive signal to the at least one of the plurality of motor windings during a time window proximate to the motor at the reference position, and wherein The position measuring module is configured to generate the position reference signal indicating the reference position during the time window.

In some embodiments of the electronic circuit, the modulation signal generating module includes: a lookup table, wherein the modulation value is stored corresponding to the shape of at least one of the complex modulation signals; the sawtooth generator is assembled Generating a first continuous sawtooth ramp signal having a minimum value and a maximum value and a complex value between the minimum value and the maximum value; a timing/phase error detector coupled to receive a signal representative of the zero current signal, coupled to receive a signal representative of the position reference signal, and coupled to generate a signal representative of the phase comparison signal; and a summation module And configured to add a value related to the phase comparison signal to the first continuous sawtooth ramp signal to generate a second having the minimum value and the maximum value and the complex value between the minimum value and the maximum value a continuous sawtooth ramp signal, wherein the minimum value and the maximum value of the second continuous sawtooth ramp signal are offset by the minimum value of the first continuous sawtooth ramp signal and the adjustment time of the maximum value The adjustment time is related to the phase comparison signal, wherein the adjusted continuous sawtooth ramp signal is used to successively search for values in the lookup table to generate the at least one of the complex modulation signals, and Generating at least one other modulated signal with respect to the predetermined phase relationship of the at least one of the complex modulated signals, each modulated signal being associated with the complex pulse width modulation (PWM) signal Not one.

102‧‧‧Motor control circuit

102a, 102b, 102c, 102d‧‧‧ nodes

104‧‧‧Electric motor

104a, 104b, 104c‧‧‧ winding

106‧‧‧External speed demand signal

107‧‧‧Speed demand generator

107a‧‧‧Speed demand signal

108‧‧‧ pulse width modulation generator

108a‧‧‧ pulse width modulation signal

110‧‧‧ gate driver circuit

110a, 110b, 110c, 110d, 110e, 110f‧‧‧ pulse width modulated gate drive signals

112, 114, 116, 118, 120, 122‧‧‧ transistors

112/114, 116/118, 120/122, 502, 504, 506‧‧‧ half bridge circuit

130‧‧‧Inductors

131‧‧‧Resistors

VA 136‧‧‧ rear electromotive voltage source

142‧‧‧ Position Measurement Module

142a‧‧‧ position reference signal

142b‧‧‧Control signal

144‧‧‧current measurement module

144a‧‧‧Zero current signal

146, 402‧‧‧ modulated signal generation module

146a, 146b, 146c, 242, 244, 246, 322‧‧‧ modulated waveforms

146d‧‧‧Control signal

201a, 201b, 201c, 201d, 201e, 201f, 604a, 604b, 604c, 604d‧‧‧

200, 220, 240, 260, 300, 320, 600, 620, 640, 900, 920‧‧‧ charts

202, 302‧‧‧ post electromotive force signal

208, 606, 608‧‧ ‧ time

222, 224, 226‧‧‧ Hall element signals

262, 264, 266, 304, 306, 602, 722, 742‧‧‧ current signals

308‧‧ ‧ time difference

402‧‧‧ clock signal

404‧‧θθ ramp generator

404a‧‧‧Unadjusted θ signal

406‧‧‧ total module

406a‧‧ θ signal

408‧‧‧Transformation profile lookup table and processor

408a, 622‧‧‧ modulated signals

408b, 408c‧‧‧ modulation profile

410‧‧‧Sequence/Phase Error Detector

410a‧‧‧ error signal

412a‧‧‧Adjustment signal

414‧‧‧Detected position reference signal

416‧‧‧System clock signal

418‧‧‧Detected zero current signal

VoutA, VoutB, VoutC, 124, 126, 128‧‧‧ motor drive signals

622a, 622b‧‧‧ peak time

642‧‧‧ pulse width modulation signal

642a, 642b‧‧‧high duty cycle time

702, 702', 704‧‧‧ pulse width modulation pulse

702a, 702a’‧‧‧ Steady-state part

702b, 702c, 702b', 702c', 704b, 704c‧‧‧ transient sections

802‧‧‧ Zero current detection module

804, 806‧‧‧ selectable switch

808‧‧‧First comparator

808a, 810a‧‧‧ output signal

810‧‧‧Second comparator

812‧‧‧Multiplexer

812a, 904‧‧ signals

902a, 902b, 902c, 902d‧‧‧ status

922‧‧‧Voltage waveform

922a, 922b, 922c, 922d, 922e‧‧‧ signal section

The above features of the present invention and the present invention can be more completely understood from the following detailed description of the drawings, wherein: FIG. 1 is a block diagram of an exemplary motor control circuit having a modulated signal generating module and a current measuring module; 2 shows various waveforms associated with the exemplary motor control circuit of FIG. 1, particularly when the motor control circuit is used to provide sinusoidal drive to the motor; FIG. 3 is another display of various waveforms associated with the exemplary motor control circuit of FIG. a picture, in particular, when the motor control circuit is used to provide a sinusoidal drive When the motor is connected to the motor, the phase difference between the current signal and the position reference signal is displayed; FIG. 4 is a block diagram of the exemplary modulation signal generating module, which can be used as the modulation signal generating module of the exemplary motor control circuit of FIG. 1; 5 and 5A are block diagrams showing an exemplary half-bridge output stage of the exemplary motor control circuit of FIG. 1 and showing the direction of motor winding current at different operating phases; FIG. 6 shows waveforms associated with motor windings, In particular, a sinusoidal current, a modulated waveform associated with a sinusoidal drive of the motor winding, and a pulse width modulated (PWM) signal that drives the motor in accordance with the modulated waveform; FIG. 7 is an image showing the PWM signal of FIG. Positive and negative details; Figure 7A shows the PWM drive signal applied to the electric motor and shows the sinusoidal current associated with the PWM drive signal; Figure 8 shows the modulated signal generation module with zero current detection module A block diagram of another exemplary motor control circuit of the current measurement module; and FIG. 9 shows various waveforms whereby the zero current in the motor winding can be detected, particularly when using a trapezoidal drive for the motor.

Before describing the invention, a number of introductory concepts and terms are described. As used herein, the term "modulation waveform" is used to describe the envelope or characteristic function of another signal, such as a pulse width modulation (PWM) signal.

Referring to FIG. 1, an exemplary motor control circuit 102 is coupled to drive an electric motor 104.

Motor 104 is shown to include three windings 104a, 104b, 104c, each of which is generally described as an individual equal circuit having an inductor in series with a resistor and in series with a rear EMF voltage source. For example, winding A 104a is shown to include an inductor 130 in series with resistor 131 and in series with rear EMF voltage source VA 136. When current flows into the associated motor winding, the voltage of the rear EMF voltage source VA 136 cannot be directly observed, but can be directly observed when the current through the associated winding is zero.

Typically, the voltage across the motor winding, for example across winding A 104a, is determined by the equation: VoutA - Vcommon = VA + IR + LdI / dt, where: VoutA = voltage observable at one end of winding A; Vcommon = voltage at the junction of windings 104a, 104b, 104c; R = resistance of resistor 131; L = inductance of inductor 130; I = current through winding; and VA = post EMF voltage

Thus, it can be seen that if the current through the winding 104a is zero, then VoutA = VA, which is an observable voltage.

Motor control circuit 102 includes a speed demand generator 107 coupled to receive external speed requirements from outside of motor control circuit 102 Signal 106. The external speed demand signal 106 can be one of a variety of formats. Typically, the external speed demand signal 106 is an indication of the speed of the motor 104 that is requested from outside the motor control circuit 102.

The speed demand generator 107 is assembled to generate a speed demand signal 107a. A pulse width modulation (PWM) generator 108 is coupled to receive the speed demand signal 107a and to be assembled to generate the PWM signal 108a, the maximum duty cycle of which is controlled by the speed demand signal 107a. The PWM generator 108 is also coupled to receive the modulated waveforms 146a, 146b, 146c from the modulated signal generation module 146. The PWM signal 108a is generated with modulation characteristics according to the modulated waveforms 146a, 146b, 146c (i.e., relative time varying duty cycles). The modulated waveform and associated PWM signals are more fully described below in conjunction with FIG.

The motor control circuit 102 also includes a gate driver circuit 110 coupled to receive the PWM signal 108a and assembled to generate PWM gate drive signals 110a, 110b, 110c, 110d, 110e, 110f for driving, configured as a three-half bridge circuit Six transistors 112, 114, 116, 118, 120, 122 of 112/114, 116/118, 120/122. The six transistors 112, 114, 116, 118, 120, 122 are saturated to provide three motor drive signals VoutA, VoutB, VoutC, 124, 126, 128, respectively, at nodes 102d, 102c, 102b.

The motor control circuit 102 can also include a position measurement module 142 that can be coupled to receive a rear EMF signal (eg, can be coupled to receive one or more of the motor drive signals 124, 126, 128, including when The undriven motor windings 104a, 104b, 104c and the individual winding currents are The zero-time can be directly observed after the EMF signal) or the Hall element signal from the Hall element (not shown). The position measurement module 142 is assembled to generate a position reference signal 142a indicative of a rotational reference position of the motor 104.

The motor control circuit 102 can also include a current measurement module 144 that can be coupled to receive one of the motor drive signals 124, 126, 128. Current measurement module 144 is configured to generate a zero current signal 144a indicative of zero crossing of current via one or more motor windings. An exemplary current measurement module is described in further detail below in conjunction with FIG.

The modulation signal generation module 146 is coupled to receive the position reference signal 142a and the zero current signal 144a. The modulated signal generation module 146 is configured to change the phase of the modulated waveforms 146a, 146b, 146c based on the phase difference between the position reference signal 142a and the zero current signal 144a. An exemplary modulated signal generation module 146 is described below in conjunction with FIG.

Motor control circuit 102 can be coupled to receive motor voltage VMOT (or VM only) at node 102a, which is supplied to the motor via transistors 112, 116, 120 when the upper transistors 112, 116, 120 are turned on. It will be appreciated that when the transistors 112, 116, 120 are turned on and supply current to the motor 104, there may be a small voltage drop (e.g., 0.1 volts) through the transistors 112, 116, 120.

As explained above, the motor control circuit 102 can automatically adjust the timing, i.e., phase, of the drive signals 124, 126, 128 with respect to the sensed rotational position of the motor 104.

Referring now to Figure 2, charts 200, 220, 240, and 260 have horizontal axes with time units in arbitrary units. Chart 200, 220, 240 have a vertical axis with an arbitrary unit of voltage unit scale. Graph 260 has a vertical axis with an arbitrary unit of current unit scale.

Signal 202 is representative of an EMF signal (ie, a voltage signal) after one of the motor windings of motor 104 of FIG. 1 (eg, winding A 104a) as motor 104 rotates. The post EMF voltage 202 is generally sinusoidal.

In several embodiments of the motor control circuit 102 of FIG. 1, the zero crossing of the rear EMF signal 202 is available to the position measurement module 142 for identifying the reference rotational position of the motor 104. It is desirable at time 208 that the zero crossing of the rear EMF signal 202 coincides or nearly coincides with the zero current through the motor winding on which the post EMF signal 202 is generated. These relationships will result in more efficient motor operations.

In several embodiments of the motor control circuit 102, the rear EMF signal is not used to detect the rotational position of the motor 104. Rather, the Hall element is located adjacent the motor 104 and produces Hall element signals 222, 224, 226 as the motor 104 rotates. It should be understood that the signals 222, 224, 226 are representative of the rotational position of the motor 104. Typically, it can be seen that there is no zero crossing of the EMF signal 202 after the conversion of the Hall element signals 222, 224, 226. However, time 208 may be identified by signals 222, 224, 226 as portions of the particular transitions of signals 222, 224, 226, such as half.

Signals 242, 244, 246 are representative of modulated waveforms 146a, 146b, 146c of FIG. 1 described above. The modulated waveforms 242, 244, 246 are used to generate a PWM signal to drive the motor 104. The pair between the modulated waveforms 242, 244, 246 and the PWM signals will be more fully described below with reference to FIG. should.

It will be appreciated that the modulated waveform 242 is associated with the winding A 104a of FIG. 1 and generally mates with the EMF signal 202 after being associated with the same winding. Other modulation waveforms 244, 246 are associated with other windings B 104b, windings C 104c of motor 104 of FIG. 1, respectively.

Signals 262, 264, 266 are representative of the currents appearing on winding A 104a, winding B 104b, winding C 104c of motor 104 of Fig. 1, respectively. It will be understood that the actual current signal on the motor windings can be more complex than that shown in signals 262, 264, 266. However, current signals 262, 264, 266 are representative of the average current through the three motor windings versus time. It will be understood that the current 262 on the motor winding A 104a is generally in phase with the rear EMF signal 202. However, as explained more fully below in connection with FIG. 3, there may be a phase difference between the current signal 262 and the associated post EMF signal 202.

The electrical rotation of the motor 104 can be divided into six states or periods 201a, 201b, 201c, 201d, 201e, 201f.

Referring now to Figure 3, chart 300 has a horizontal axis with a scale of time units in arbitrary units. The graph 300 also has a vertical axis with arbitrary units of voltage and current unit scales. Graph 320 has a horizontal axis with a scale of time units in arbitrary units. Graph 320 also includes a vertical axis having an arbitrary unit of voltage unit scale.

Signal 304 is representative of the current signal on winding A 104a of FIG. Thus, signal 304 corresponds to signal 262 of FIG. Signal 302 is representative of EMF signal 136 after winding A 104a of FIG. Thus, signal 302 corresponds to signal 202 of FIG. The zero crossing of signals 302, 304 will be apparent. The time difference 308 is an indication of the time difference between the zero crossing of the rear EMF signal 302 and the zero crossing of the current signal 304. Thus, the time difference 308 is representative of the time difference between the rotational position reference (i.e., the zero crossing of the rear EMF signal 302) and the zero current through the associated motor winding.

Signal 306 is representative of the current signal of winding A 104a of FIG. 1 during acceleration of the rotational speed of motor 104 or during high speed rotation of motor 104. It can be seen that the relative phase has shifted. The zero crossing of current signal 306 is delayed relative to the zero crossing of back EMF signal 302. The zero crossing of the rear EMF signal 302 is an indication of the reference rotational position of the motor 104. The zero crossing of current signal 306 is representative of the zero current through motor winding A 104a. It is hoped that the zero crossing time and phase are consistent. Lack of time consistency will result in increased motor noise and vibration and reduced motor efficiency.

The modulated waveform 322 is the same or similar to the modulated waveform 242 of FIG. Thus, when the motor accelerates or rotates rapidly, the current signal 306 can be seen to be delayed relative to the modulated waveform 322. It is desirable to advance the modulated waveform 322 (i.e., shift the modulated waveform 322 to the left) to advance the current signal 306 such that the zero crossing of the current signal 306 can occur coincident or nearly coincident with the zero crossing of the back EMF signal 302, the post EMF signal An indication of the rotational reference position of the zero-crossing motor 104 of 302.

In general, the modulated signal generation module 146 of FIG. 1 can advance or delay various modulated waveforms 146a, 146b, 146c according to the received rotational position reference signal 142a and according to the zero current signal 144a, and The post EMF signal 302 and the current signals 304, 306 are representative of it.

For conventional sinusoidal motor drive signals, such as those described above in connection with Figures 2 and 3, for the reasons described above in connection with Figure 1, each of the motor windings 104a, 104b, 104c is continuously driven, which is not readily The zero crossing of the EMF signal 302 is observed and detected. In order to observe the post-EMF signal, it is necessary to stop the drive signal to the motor winding at least instantaneously. Thus, based on the sinusoidal motor drive signal configuration, in some embodiments, the sinusoidal drive signal to at least one of the windings 104a, 104b, 104c of the motor 104 can be stopped for a small time window to observe the zero crossing of the rear EMF signal. To this end, in the motor control circuit 102 of FIG. 1, the control signal 142b can be provided by the position measuring module 142 to the gate driver 110.

Referring now to FIG. 4, the modulated signal generation module 402 can be used as the modulated signal generation module 146 of FIG.

The modulated signal generating module 402 is coupled to receive the detected position reference signal 414 and the detected zero current signal 418. The detected position reference signal 414 can be the same or similar to the position reference signal 142a of FIG. The detected zero current signal 418 can be the same or similar to the zero current signal 144a of FIG.

As explained above, the detected position reference signal 414 can be generated by using a short crossing of the EMF signal after the sinusoidal drive waveform is used by using a short period of time for the sinusoidal drive to stop. In other embodiments, the detected position reference signal 414 can be generated in conjunction with the Hall element and associated Hall element signals disposed adjacent the motor 104 of FIG.

The modulated signal generating module 402 is also coupled to receive the solid A high frequency system clock signal 416 is asserted.

The so-called "θ ramp generator" 404 is coupled to receive the detected position reference signal 414 and the system clock signal 416. The θ ramp generator 404 is assembled to generate an unadjusted θ signal 404a, which may be a digital signal comprising a string of ramp signal values representative of a periodic arrival of the terminal value and reset to zero. The reset time of the ramp signal is fixed with respect to the detected position reference signal 414 as the indicated position reference (i.e., the fixed rotational position of the motor 104).

In operation, the θ ramp generator 404 can identify the time period measured by counting a number of system clock transitions between the position references identified by the detected position reference signal 414. In other words, the θ ramp generator 404 can identify the time it takes for the motor 104 to rotate through an electrical rotation (ie, the number of transitions of the system clock signal 416). The θ ramp generator 404 can divide the number of conversions of the identified system clock 416 by a fixed amount, such as 256. Thus, the motor electrical rotation can be divided into 256 parts. Thus, the clock signal 422 can have a frequency that achieves, for example, 256 transitions during one electrical rotation of the motor. The clock signal 422 can be generated by the θ ramp generator 404 and used to generate a ratio, whereby the ramp value of the unadjusted θ signal 404a is increased and output in the unadjusted θ signal 404a. Thus, it will be understood that the ramp signal in each of the electrical rotations of the motor reaching the unadjusted theta signal 404a is reset to zero once and may be, for example, 256 steps in the ramp.

The timing/phase error detector 410 is coupled to receive the detected zero current signal 418, coupled to receive the detected position reference signal 414, and coupled to receive the clock signal 402.

The timing/phase error detector 410 is configured to identify the position reference identified by the detected position reference signal 414 and the time difference (i.e., phase difference) between the zero current crossings identified by the detected zero current signal 418.

Referring briefly again to FIG. 3, in other words, the timing/phase error detector 410 is operable to identify the time difference between the zero crossing of the current signal 304 or 306 and the zero crossing of the rear EMF voltage signal 302.

Referring again to Figure 4, the timing/phase error detector 410 is assembled to generate an error signal 410a, which in several embodiments may be a digital value representing the time (i.e., phase) difference of the identification.

A proportional integrator differentiator (PID) or, in other embodiments, a proportional integrator (PI) may be coupled to receive the error signal 410a, and assembled to substantially filter the error signal 410a to produce the adjustment signal 412a. In some embodiments, the adjustment signal 412a can be a digital value that is proportional to the time difference identified by the timing/phase error detector 410.

The summation module 406 is coupled to receive the unadjusted θ signal 404a (ie, a contiguous set represented by the digital value of the fixed phase reset ramp signal), coupled to receive the adjustment signal 412a, and configured to A θ signal 406a is generated.

In operation, it should be understood that the θ signal 406a is a reset ramp signal like the unadjusted θ signal 404a, but wherein the reset time of the ramp signal is moved in time according to the value of the adjustment signal 412a, that is, the phase of the adjustment.

The modulation profile lookup table and processor 408 are coupled to receive the θ signal 406a. The modulation profile lookup table and processor 408 are assembled A value representative of one or more of the modulation profiles is stored, such as the modulation profile 242 of FIG.

During operation, the θ signal 406a is used between the modulation profile lookup table and the value of the modulation signal stored in the processor 408. It will be understood that the phase of the θ signal 406a represented by the reset portion of the θ signal 406a can be adjusted to be identified based on the time difference between the position reference identified in the detected position reference signal 414 and the zero crossing of the current in the motor winding. Within the detected zero cross signal 418. Therefore, the phase, ie timing, of the modulation signal 408a generated by the modulation profile lookup table and processor 408 is adjustable.

The processor portion of the modulation profile lookup table and processor 408 can automatically generate other modulation profiles 408b, 408c, such as the modulation profiles 244, 246 of FIG. 2, which can be relative to the modulation profile, for other fixed phases. The fixed phase of 408a, such as the modulation profile 242 of FIG.

Exemplary circuits and methods for detecting zero current through a motor winding are described below in conjunction with FIGS. 5-8. However, it should be understood that other methods can be used to detect zero current through the motor windings.

Referring now to Figure 5, three half bridge circuits 502, 504, 506 corresponding to the three half bridge circuits 112/114, 116/118, 120/122 of Figure 1 are shown driving the three motor windings. The current through the half bridge circuit 502 and through one of the motor windings is indicated by the dashed lines identified as circle numbers 1, 2 and 3. Currents 1, 2, and 3 are indicative of the current through the half bridge circuit 502 at different times during the positive phase of the current signal in the motor winding, such as during the positive portion of the current signal 262 of FIG. Current 1 is above The indication of the FET, current 3 is an indication of the FET under turn-on, and an indication of the second FET with current 2 turned off. It will be understood that the current 2 passes through the intrinsic diode of the lower FET, thus, when the second FET of the half bridge 502 is turned off, and when the current FET is turned on and returns to the ground voltage, the voltage VoutA (see, for example, the signal 124 of FIG. 1) is reached. Below 0.7 volts at the beginning of grounding. Thus, it will be understood that the actual zero current through the half bridge 502 and through the associated motor windings can be identified by detecting the existing voltage VoutA below ground and returning to ground.

Referring now to Figure 5A, wherein elements similar to Figure 5 are shown with similar designations, the current through the half bridge circuit 502 and through one of the motor windings is again indicated by the dashed lines identified as circle numbers 1, 2 and 3. Currents 1, 2, and 3 are indications of the current through the half bridge circuit 502 at different times during the negative phase of the current signal in the motor winding, such as during the negative portion of the current signal 262 of FIG. Current 1 is an indication of turning on the upper FET, current 3 is an indication of the FET under turn-on, and current 2 is an indication of the second FET being turned off. It will be understood that the current 2 passes through the intrinsic diode of the upper FET, so that when the two FETs of the half bridge 502 are turned off, and when the upper FET is turned on and returns to the voltage VM, the voltage VoutA reaches about 0.7 volts above the start of the voltage VM. Voltage. Thus, it will be understood that the actual zero current through the half bridge 502 and through the associated motor windings can be identified by detecting the existing voltage VoutA above the voltage VM and returning to the voltage VM.

Referring now to Figure 6, chart 600 has a horizontal axis having an arbitrary unit of time unit scale and a vertical axis having an arbitrary unit of current unit scale. Graph 620 has a horizontal axis with an arbitrary unit of time unit scale and A vertical axis with a unit of voltage unit of any unit. Graph 640 has a horizontal axis with an arbitrary unit of time unit scale and a vertical axis with an arbitrary unit of voltage unit scale.

Signal 602 is representative of the current signal in motor winding A when a sinusoidal drive signal is used. Current signal 602 can be the same or similar to current signal 262 of FIG. As explained above, current signal 602 can occur more complexly when using a PWM drive signal, but signal 602 is a general representation of the average current through winding A. The current signal has a zero crossing at times 606, 608.

The modulated signal 622 can be the same or similar to the modulated signal 242 of FIG. The modulated signal 622 can have six periods or phases, four of which are shown as 604a, 604b, 604c, 604d.

The PWM signal 642 can be generated according to the modulation signal 622, and can have a high duty cycle time 642a, 642b at the peak time 622a, 622b of the modulation waveform 622 according to the value of the modulation signal 622, and other modulation signal 622 Part time has a lower duty cycle time. The PWM signal 642 can be a sinusoidally driven signal that is actually applied to the motor winding A 104a of the motor 104 of FIG.

Referring now to Figure 7, PWM pulses 702, 702' are indicative of the PWM pulse 642 of Figure 6 during the negative polarity portion of current signal 602. PWM pulse 704 is an indication of PWM pulse 642 of FIG. 6 during the positive polarity portion of current signal 602.

The PWM pulses 702, 702' have rising or transient portions 702b, 702c, 702b', 702c' and steady state portions 702a, 702a'. according to As discussed above in connection with Figures 5 and 5A, it will be understood that when the half-bridged two transistors are turned off, such as FETs, the voltage VoutA appearing on the associated motor winding temporarily exceeds the motor voltage VM or below ground, depending on the motor winding. The polarity of the current in the line, that is, the polarity of the current signal 602. It will also be understood that the two FETs are turned off for a short period of time before each major edge transition of the PWM signals 702, 704, 702', otherwise the two FETs may be turned on at the same time, resulting in a short between the motor voltage VM and ground. Thus, when the two FETs are turned off, transient signal portions 702b, 702c, 704b, 704c, 702b', 702c' are generated. Transient signal portions 702b, 702c, 704b, 704c, 702b', 702c' may occur for a short period of time, such as about 500 nanoseconds.

It will be understood that the direction of the transient voltage signal portions 702b, 702c, 704b, 704c, 702b', 702c' changes each time a zero crossing of the current signal 602 occurs, i.e., times 606, 608. Thus, the detection of the change in direction of the transient signal portions 702b, 702c, 704b, 704c, 702b', 702c' can be used to identify the zero current in the associated motor winding.

Referring now to Figure 7A, chart 720 has a horizontal axis having an arbitrary unit of time unit scale and a vertical axis having an arbitrary unit of voltage unit scale. Graph 740 has a horizontal axis with an arbitrary unit of time unit scale and a vertical axis with an arbitrary unit of current unit scale.

Signal 722 is representative of PWM signal 642 of Figure 6, but the transient signal portion is shown as transient portions 702b, 702c, 704b, 704c, 702b', 702c' of Figure 7. Signal 742 is the same or similar to current signal 602 of FIG.

Time t1-t9 occurs during the transient signal portion. From above In conjunction with the discussion of Figures 5 and 5A, it will be understood that a transient signal portion occurs when the two FETs of the associated half-bridge circuit of the drive motor winding are closed.

For the reasons described above in connection with Figures 5, 5A, and 7, at time t6, the transient signal portion change direction coincides with or nearly coincides with the zero crossing of current signal 742. Thus, the change in direction of the transient signal portion can be used to detect zero current crossings in the motor windings. In particular, at time t1-t5, the transient signal portion extends beyond the motor voltage VM. Conversely, at time t6-t9, the transient signal portion extends below ground. Another change or direction of the transient signal portion (not shown) occurs at zero crossing below current signal 742 and can also be used to detect the next zero crossing.

In some embodiments, the circuitry (such as, for example, comparators 808, 810 shown in FIG. 8 below) is operable to sample signal VoutA 722 and detect only signal transient portions at time t1-t9 or near time t1-t9, And other similar times after that. A similar time at times t1-t9 and after is known since the two FETs are temporarily turned off during these times. In other embodiments, signal 722 can be continuously sampled to detect portions of the transient signal.

In some embodiments, the two comparators can detect the change in direction of the transient signal portion. The two-way intersection of the current signal 742 can be detected. However, in other embodiments, a comparator can be used to detect the presence or absence of a transient signal portion extending up or down. Moreover, a comparator can detect the intersection of the current signal 742.

Referring now to Figure 8, wherein elements similar to those of Figure 1 are shown with similar designations, the zero current detection module 802 can be the same or similar to Figure 1 Current measurement module 144.

The zero current detection module 802 can include a first comparator 808 coupled to the three motor windings via a selectable switch 804. The zero current detection module 802 can also include a second comparator 810 coupled to the three motor windings via the selectable switch 806. The first comparator 808 can be coupled to receive a reference voltage equal to or near the motor voltage VM. The second comparator 810 can be coupled to receive a reference voltage equal to or near ground.

The first comparator 808 is assembled to generate an output signal 808a indicative of the voltage of the motor winding on the selection of the excess motor voltage. The second comparator 810 is configured to generate an output signal 810a indicative of a voltage present on the motor winding below the selected ground. Thus, in operation, the first comparator 808 is operable to detect the positive transient signal portions 702b, 702c, 702b', 702c' of the PWM signal of Figure 7 associated with the sinusoidal motor drive. Similarly, in operation, the second comparator 810 is operable to detect negative transient signal portions 704b, 704c of the PWM signal of FIG. 7 associated with sinusoidal motor drive. As explained above, the edges of the signal portions can be used to identify zero current crossings in the associated motor windings.

The zero current detection module 802 can also include a multiplexer 812 coupled to receive the output signals 808a, 810a and a signal 812a that is coupled to generate and output one of the selected output signals 808a, 810a.

The multiplexer 812 can be coupled to receive the control signal 146d from the modulated signal generation module 146. Switches 804, 806 can be coupled to receive other control signals (not shown) from modulation signal generation module 146.

The modulated signal generation module 146 can use various types of logic to identify zero current crossings in one or more motor windings. For example, as discussed above in connection with Figures 7 and 7A, for PWM sinusoidal motor drive signals, output signals 808a, 810a may be used to identify transient signal portions 702b, 702c, 704b, 704c, 702b', 702c' of PWM signal 642. The direction changes. In essence, when performing a particular direction detection of the transient signal portion, multiplexer 812 can switch to view other comparators.

In several embodiments, no switches are used and only one motor winding is used to provide signals to the comparators 808, 810. In several embodiments, only one comparator is used and multiplexer 812 is not necessary. When the voltage on the motor winding exceeds the motor voltage VM and/or is below ground, various different types of logic are available for the modulated signal generation module 146 to identify the winding through the motor by using the detection techniques described above. The zero crossing of the current.

Referring now to Figure 9, chart 900 has a horizontal axis with a scale of time units in arbitrary units. Graph 900 also has a vertical axis with an arbitrary unit of current unit scale. Graph 920 has a horizontal axis with a scale of time units in arbitrary units. Graph 920 also has a vertical axis with an arbitrary unit of voltage unit scale.

In contrast to the sinusoidal motor drive signals described above, signal 904 is representative of a trapezoidal motor drive. Signal 904 is representative of a trapezoidal current signal on the motor winding.

It will be understood that voltage waveform 922 is representative of the voltage that is actually applied to the motor winding for 100% motor drive. Driven by 100% motor, signal 922 reaches VM voltage with 100% duty cycle (motor voltage), while other times are zero. For less than one hundred percent different trapezoidal motor drives (not shown), different ladder motor drives provide pulse width modulation with a duty cycle of less than one hundred percent motor drive during a period of one hundred percent drive signal 922 reaching the VM voltage. Pulse width modulation signal.

The time during which the motor is electrically rotated can be divided into six states, and only the four states 902a, 902b, 902c, and 902d are displayed. The signals during the other two states will be obvious. Each motor winding receives a motor drive signal like the motor drive signal 922, but with a phase offset and starting from a different phase.

Based on the trapezoidal drive, the drive signal applied to the motor winding during the first phase 902a is zero and the fourth phase 902d is also zero. Thus during the first and fourth phases 902a, 902d, the current signal 904 reaches zero current during the signal portion 904a and during the signal portion 904d. Due to the sensing behavior of the motor winding, zero current is not immediately reached at the beginning of the first and fourth phases 902a, 902d. For the reasons explained above in connection with Fig. 1, when the driving voltage applied to the winding is zero and the current decays to zero, the EMF voltage after the winding is directly observed.

For reasons fully explained above in connection with Figures 5 and 5A, during signal portion 922a, signal 922 on the motor winding reaches the voltage of VM + Vd, and during signal portion 922d, signal 922 reaches the voltage of -Vd. An exemplary method of detecting zero current during signal portions 904a, 904d is described above in connection with Figures 5 and 5A. To this end, portions 922a, 922d of signal 922 can be used to detect zero wire currents using circuitry and techniques such as those described above in connection with Figures 5, 5A and 8.

During partial first and fourth phases 902a, 904d, in particular, during the dashed portions 922b, 922e of voltage signal 922, the rear EMF voltage can be directly observed. During portions 922b, 922e of voltage signal 922, and during portions 922a, 922d, no drive signal is applied to the associated motor. As explained above, the induced behavior of the motor windings causes the current to reach zero current through the motor windings only during portions 922b, 922e of drive signal 922.

From the above discussion, it should be understood that based on the trapezoidal drive and the use of the six motor drive state, there is a substantial period of time during which each motor winding is not driven, such as a signal that occupies one sixth (i.e., 60 degrees) of the motor's electrical rotation. During the period associated with portions 922a, 922b, and during periods associated with signal portions 922d, 922e that together occupy another one-sixth (i.e., 60 degrees) of motor electrical rotation, the motor windings are not driven. The current through the motor winding becomes zero at the end of the transient signal portions 922a, 922d, i.e., during the signal portions 922b, 922e. During the signal portions 922b, 922e, the back EMF voltage can be directly observed. Thus, unlike the sinusoidal drive described above, for a continuously driven motor winding, based on a six-state trapezoidal drive configuration, there is no need to separately generate a time window during which no motor drive is applied to the winding to detect transient signals. Portions 922a, 922d have an indication of zero winding current at their ends, or a zero crossing during detection of signal portions 922b, 922e, which is an indication of the rotational position of the motor.

All references cited herein are hereby incorporated by reference in their entirety.

Preferred embodiments have been described for depicting the subject matter of this patent It will be apparent to those skilled in the art that <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; Therefore, the scope of the patent is not to be construed as limited to the illustrated embodiments, but only to the spirit and scope of the application.

102‧‧‧Motor control circuit

102a, 102b, 102c, 102d‧‧‧ nodes

104‧‧‧Electric motor

104a, 104b, 104c‧‧‧ winding

106‧‧‧External speed demand signal

107‧‧‧Speed demand generator

107a‧‧‧Speed demand signal

108‧‧‧ pulse width modulation generator

108a‧‧‧ pulse width modulation signal

110‧‧‧ gate driver circuit

110a, 110b, 110c, 110d, 110e, 110f‧‧‧ pulse width modulated gate drive signals

112, 114, 116, 118, 120, 122‧‧‧ transistors

124, 126, 128‧‧‧ motor drive signals

130‧‧‧Inductors

131‧‧‧Resistors

136‧‧‧ rear electromotive voltage source

142‧‧‧ Position Measurement Module

142a‧‧‧ position reference signal

142b‧‧‧Control signal

144‧‧‧current measurement module

144a‧‧‧Zero current signal

146‧‧‧ modulated signal generation module

146a, 146b, 146c‧‧‧ modulated waveform

Claims (30)

A method of driving a multi-phase motor having a plurality of motor windings, the method comprising: generating a zero current signal indicative of a zero crossing of current through at least one of the plurality of motor windings; generating a reference indicative of angular rotation of the motor a position reference signal of the position; comparing a phase of the zero current signal with a phase of the position reference signal to generate a phase comparison signal; generating a complex modulation signal, each having a phase relating to a value of the phase comparison signal; and according to the complex number And modulating the signal to generate a plurality of motor drive signals to the plurality of motor windings, wherein the generating the complex modulation signal comprises: providing a lookup table, wherein the modulation value corresponds to a shape of at least one of the complex modulation signals Preserving; generating a first continuous predetermined signal having a minimum value and a maximum value and a complex value between the minimum value and the maximum value; adding a value related to the phase comparison signal to the first continuous predetermined signal to generate the a second continuous predetermined signal of the minimum value and the maximum value and the complex value between the minimum value and the maximum value, wherein The minimum value and the maximum value of the two consecutive predetermined signals are offset in time by the minimum value of the first continuous predetermined signal and the adjustment time of the maximum value, wherein the adjustment time is related to the phase comparison signal; The adjusted continuous predetermined signal to successively search for the lookup table And generating at least one of the complex modulated signals; and generating at least one other modulated signal in a predetermined phase relationship relative to the at least one of the complex modulated signals. The method of claim 1, wherein the generating the position reference signal comprises: generating a Hall sensor signal with a Hall sensor configured to access the motor. The method of claim 1, wherein the generating the position reference signal comprises: generating a rear EMF signal with a post electromotive force (EMF) module coupled to at least one of the plurality of motor windings. The method of claim 1, wherein the generating the position reference signal comprises: stopping a motor drive signal to at least one of the plurality of motor windings during a time window of the motor proximate to the reference position; And detecting the reference position during the time window by zero crossing of the back EMF signal. The method of claim 1, wherein the generating the zero current signal comprises: generating the plurality of motor driving signals by a plurality of individual half bridge circuits coupled to the electric motor, each half bridge circuit comprising: an individual first The second series is coupled to the transistor; the individual power supply high voltage node is for receiving the high power supply voltage; the individual power supply low voltage node is for receiving the low power supply voltage; And generating, by the individual output nodes, the individual one of the plurality of motor drive signals; detecting a reverse current of at least one of the first transistor or the second transistor passing through at least one of the plurality of half bridge circuits The detecting includes at least one of: detecting a voltage higher than the high power supply voltage at the output node; or detecting a voltage lower than the low power supply voltage at the output node; and detecting the reverse according to the detecting To the current, a zero current signal is generated that indicates a zero crossing of the current through at least one of the plurality of motor windings. The method of claim 5, wherein detecting the reverse current comprises: detecting a voltage of the output node by detecting a time when the first transistor and the second transistor are both turned off This reverse current. The method of claim 1, wherein each of the plurality of motor drive signals comprises: an individual complex pulse width modulation signal, each of the plurality of pulse width signals having a steady state comprising the high supply voltage a high value and a high state above a transient high value of the higher supply voltage, and each of the complex pulse width signals also having a steady state low value close to the low supply voltage and lower than the lower supply voltage The low state of the transient low value. The method of claim 1, wherein the first continuous predetermined signal is a first continuous sawtooth ramp signal, and the second continuous predetermined The signal is a second continuous sawtooth ramp signal, and wherein the adjusted continuous predetermined signal is an adjusted continuous sawtooth ramp signal. An electronic circuit for driving a multi-phase motor having a plurality of motor windings, the electronic circuit comprising: a current measuring module configured to generate a zero current signal indicative of current passing through at least one of the plurality of motor windings a zero-crossing; a position measuring module configured to generate a position reference signal indicative of a reference position of the angular rotation of the motor; a modulated signal generating module configured to compare the phase of the zero current signal with the position reference Phases of the signals to produce phase comparison signals, and are combined to generate complex modulation signals, each having a phase relating to the value of the phase comparison signal; and a drive circuit configured to generate a modulation signal based on the complex modulation signal a plurality of motor drive signals to the plurality of motor windings, wherein the modulation signal generation module includes: a lookup table, wherein the modulation value is stored corresponding to a shape of at least one of the plurality of modulation signals; the sawtooth generation a first continuous predetermined signal having a minimum value and a maximum value and a complex value between the minimum value and the maximum value; timing/phase error a detector coupled to receive a signal representative of the zero current signal, coupled to receive a signal representative of the position reference signal, and coupled to generate a signal representative of the phase comparison signal; and a summation module configured And increasing a value related to the phase comparison signal to the first continuous predetermined signal to generate the minimum value and the maximum value And a second consecutive predetermined signal of the complex value between the minimum value and the maximum value, wherein the minimum value and the maximum value of the second consecutive predetermined signal are obtained by the minimum value from the first continuous predetermined signal and The adjustment time of the maximum value is offset in time, wherein the adjustment time is related to the phase comparison signal, wherein the adjusted continuous predetermined signal is used to successively search for values in the lookup table to generate the complex modulation signal. At least one of the at least one of the plurality of modulated signals is also generated with respect to a predetermined phase relationship of the at least one of the plurality of modulated signals. The electronic circuit of claim 9, wherein the position measuring module is further configured to generate the position signal according to a Hall signal generated by configuring a Hall sensor approaching the motor. The electronic circuit of claim 9, wherein the position measuring module is further configured to generate the position signal based on a post EMF signal generated in the motor winding. The electronic circuit of claim 9, wherein the generating the position reference signal comprises: stopping a motor drive signal to at least one of the plurality of motor windings during a time window of the motor near the reference position And detecting the reference position during the time window by zero crossing of the back EMF signal. The electronic circuit of claim 9, further comprising: a plurality of half bridge circuits coupled to the electric motor, configured to generate the plurality of motor drive signals, each half bridge circuit comprising: Individual first and second series coupled to the transistor; individual power supply high voltage nodes for receiving high supply voltage; individual power supply low voltage nodes for receiving low supply voltage; and individual output nodes for generating the complex motor drive One of the signals; at least one comparator configured to detect, by detecting, the inverse of at least one of the first transistor or the second transistor indicating the passage of at least one of the plurality of half bridge circuits Outputting a signal to at least one comparator of the current, the detecting comprising at least one of: a voltage at the output node that is higher than the high supply voltage; or a voltage at the output node that is lower than the low supply voltage; The processor is configured to generate the zero current signal based on the at least one comparator output signal indicative of the zero crossing of the current through at least one of the plurality of motor windings. The electronic circuit of claim 13, wherein the detecting comprises: detecting the reverse by sampling a voltage of the output node only when the first transistor and the second transistor are both turned off Current. The electronic circuit of claim 9, wherein each of the plurality of motor drive signals comprises: a plurality of individual pulse width modulation signals, each of the plurality of pulse width signals having a stability close to the high supply voltage a state high value and a high state higher than a transient high value of the higher power supply voltage, and the complex pulse width signal Each also has a low state that includes a steady state low value close to the low supply voltage and a transient low value that is lower than the lower supply voltage. The electronic circuit of claim 9, wherein the first continuous predetermined signal is a first continuous sawtooth ramp signal, and the second continuous predetermined signal is a second continuous sawtooth ramp signal, and wherein the adjusting The continuous predetermined signal is an adjusted continuous sawtooth ramp signal. A method of driving a multi-phase motor having a plurality of motor windings, the method comprising: generating a motor drive signal by a half bridge circuit coupled to the electric motor, the half bridge circuit comprising: first and second series coupled transistors a power supply high voltage node for receiving a high power supply voltage; a power supply low voltage node for receiving a low power supply voltage; and an output node for generating the motor drive signal; detecting the first transistor or the second battery a reverse current of at least one of the crystals, wherein the detecting comprises at least one of: detecting a voltage higher than the high supply voltage at the output node; or detecting that the output node is below the low supply voltage a voltage, wherein the method further comprises: generating a zero current signal indicative of a zero crossing of current through at least one of the plurality of motor windings based on the detecting the reverse current; generating a reference indicative of angular rotation of the motor a position reference signal of the position; comparing the phase of the zero current signal with the phase of the position reference signal Generating a phase comparison signal; generating a plurality of modulated signals, each having a phase relating to a value of the phase comparison signal; and generating a plurality of motor drive signals to the plurality of motor windings based on the complex modulated signal, wherein the generating The complex modulation signal includes: providing a lookup table, wherein the modulation value is stored corresponding to a shape of at least one of the complex modulation signals; generating a minimum value and a maximum value and the minimum value and the maximum value a first continuous predetermined signal of a complex value; adding a value related to the phase comparison signal to the first continuous predetermined signal to generate the complex value between the minimum value and the maximum value and the minimum value and the maximum value a second continuous predetermined signal, wherein the minimum value and the maximum value of the second consecutive predetermined signal are offset in time by the adjustment time from the minimum value of the first continuous predetermined signal and the maximum value, wherein The adjustment time is related to the phase comparison signal. The method of claim 17, wherein detecting the reverse current comprises: detecting the voltage of the output node only when the first transistor and the second transistor are both off Reverse current. The method of claim 17, wherein the motor drive signal comprises: a plurality of pulse width modulation signals, each of the plurality of pulse width signals having a steady state high value close to the high power supply voltage and higher than the a high state of a transient high value of a higher power supply voltage, and each of the complex pulse width signals The device also has a low state comprising a steady state low value close to the low supply voltage and a transient low value below the lower supply voltage. The method of claim 17, wherein the generating the position reference signal comprises: generating a Hall sensor signal with a Hall sensor configured to be in proximity to the motor. The method of claim 17, wherein the generating the position reference signal comprises generating a rear EMF signal with a post electromotive force (EMF) module coupled to at least one of the plurality of motor windings. The method of claim 17, wherein the generating the position reference signal comprises: stopping a motor drive signal to the at least one of the plurality of motor windings during a time window of the motor proximate to the reference position And detecting the reference position during the time window by zero crossing of the back EMF signal. The method of claim 17, wherein the generating the complex modulated signal further comprises: using the adjusted continuous predetermined signal to successively search for values in the lookup table to generate the at least one of the complex modulated signals And generating, by the predetermined phase relationship with respect to the at least one of the plurality of modulated signals, at least one other modulated signal, each modulated signal being associated with an individual one of the complex pulse width modulated (PWM) signals. A multi-phase motor for driving a plurality of motor windings An electronic circuit comprising: a half bridge circuit coupled to the electric motor for generating a motor drive signal, the half bridge circuit comprising: first and second series coupled transistors; for receiving a high power supply voltage a power supply high voltage node; a power supply low voltage node for receiving a low power supply voltage; and an output node for generating the motor drive signal; at least one comparator configured to generate an indication by the first power At least one comparator output signal of the reverse current of at least one of the crystal or the second transistor, the detecting comprising at least one of: a voltage at the output node that is higher than the high supply voltage; or a voltage of the output node that is lower than the low supply voltage, wherein the electronic circuit further includes: a processor configured to generate a zero current signal based on the at least one comparator output signal indicating that the motor is wound by the plurality of motors a zero crossing of current of at least one of; a position measuring module configured to generate a position reference signal indicative of a reference position of angular rotation of the motor; a signal generating module configured to compare a phase of the zero current signal with a phase of the position reference signal to generate a phase comparison signal, and configured to generate a plurality of modulated signals, each having a phase comparison signal a phase of the value, wherein the modulation signal generation module includes: a lookup table, wherein the modulation value is stored corresponding to a shape of at least one of the complex modulation signals; a sawtooth generator configured to generate a first continuous predetermined signal having a minimum value and a maximum value and a complex value between the minimum value and the maximum value; a timing/phase error detector coupled to receive the zero current representative a signal signal coupled to receive a signal representative of the position reference signal and a signal coupled to generate a signal representative of the phase comparison signal; and a summation module configured to increase a value associated with the phase comparison signal to the a first continuous predetermined signal to generate a second continuous predetermined signal having the minimum value and the maximum value and the complex value between the minimum value and the maximum value, wherein the minimum value of the second consecutive predetermined signal and the The maximum value is offset in time by the minimum value from the first continuous predetermined signal and the adjustment time of the maximum value, wherein the adjustment time is related to the phase comparison signal. The electronic circuit of claim 24, wherein the detecting comprises: detecting the reverse by sampling a voltage of the output node only when the first transistor and the second transistor are both turned off Current. The electronic circuit of claim 24, wherein the motor driving signal comprises: a plurality of pulse width modulation signals, each of the plurality of pulse width signals having a steady state high value close to the high power supply voltage and higher than a high state of the transient high value of the higher supply voltage, and each of the complex pulse width signals also has a steady state low value close to the low supply voltage and a transient low value lower than the lower supply voltage Low state. Such as the electronic circuit of claim 24, wherein the bit The set measurement module is further configured to generate the position signal based on a Hall signal generated by configuring a Hall sensor proximate to the motor. The electronic circuit of claim 24, wherein the position measuring module is further configured to generate the position signal based on a post EMF signal generated in the motor winding. The electronic circuit of claim 24, wherein the electronic circuit is configured to stop a motor drive signal to the at least one of the plurality of motor windings during a time window of the motor proximate to the reference position And wherein the position measuring module is configured to generate the position reference signal indicating the reference position during the time window. The electronic circuit of claim 24, wherein the adjusted continuous predetermined signal is used to successively search for values in the lookup table to generate the at least one of the complex modulated signals, and is also used to The predetermined phase relationship of the at least one of the plurality of modulated signals produces at least one other modulated signal, each modulated signal being associated with an individual one of the plurality of complex pulse width modulated (PWM) signals.