CN113411014B - Electro-magnetic doubly salient motor control method for inhibiting torque pulsation based on torque closed loop - Google Patents
Electro-magnetic doubly salient motor control method for inhibiting torque pulsation based on torque closed loop Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
- H02P6/10—Arrangements for controlling torque ripple, e.g. providing reduced torque ripple
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P25/00—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
- H02P25/02—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the kind of motor
- H02P25/08—Reluctance motors
- H02P25/098—Arrangements for reducing torque ripple
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
- H02P6/14—Electronic commutators
- H02P6/15—Controlling commutation time
- H02P6/153—Controlling commutation time wherein the commutation is advanced from position signals phase in function of the speed
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
- H02P6/32—Arrangements for controlling wound field motors, e.g. motors with exciter coils
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Abstract
The invention discloses an electro-magnetic doubly salient motor control method for inhibiting torque pulsation based on torque closed loop, which relates to the field of electro-magnetic doubly salient motors, the method determines a motor torque set value corresponding to a motor rotor position theta based on a rotating speed regulator, determines a motor torque feedback value according to the motor rotor position and phase current values of three phase windings, generating a first control signal having a predetermined duty ratio based on the motor torque setpoint and the motor torque feedback value, determining a second control signal corresponding to the position of the motor rotor according to a second preset corresponding relation, generating a driving signal by the first control signal and the second control signal to drive all power tubes in the three-phase bridge power circuit, the method adopts a torque closed loop to replace a current closed loop, directly controls the output torque of the motor, can effectively inhibit the torque pulsation of a phase commutation stage and a non-phase commutation stage, and has a relatively simple control structure.
Description
Technical Field
The invention relates to the field of an electro-magnetic doubly salient motor, in particular to an electro-magnetic doubly salient motor control method for inhibiting torque pulsation based on torque closed loop.
Background
The electric excitation double-salient motor is developed on the basis of a permanent magnet double-salient motor, and an excitation winding is adopted on a motor stator to replace stator magnetic steel of the permanent magnet double-salient motor, so that the excitation is easy to adjust, and the field weakening control, field extinction and the like are facilitated. The electro-magnetic doubly salient motor has the advantages of simple structure, low cost, high reliability and good fault tolerance, and has wide application prospect in the fields of hybrid electric vehicles, aviation and the like.
However, the reluctance motor has a problem of large torque ripple due to the structure of doubly salient poles of a stator and a rotor of an electro-magnetic doubly salient motor. In addition, the traditional control mode of the electro-magnetic doubly salient motor adopts square wave current driving, and when phase of each phase current is subjected to phase transformation, the follow current process of the phase current can further aggravate the torque pulsation of the motor. The problems of large noise and violent vibration of the motor are caused by large torque pulsation of the motor, and the popularization and the application of the motor are restricted to a certain extent.
At present, the research directions for suppressing torque ripple of an electro-magnetic doubly salient motor are mainly divided into two main categories: the first type is to reduce the torque ripple by optimizing the design of the doubly salient electro-magnetic motor body, but the optimization effect of the method is general, so that the method is not the current important research direction. The second type is a control strategy for optimizing an electro-magnetic doubly salient motor to reduce torque ripple, and mainly adopts an angle optimization control strategy, namely a control strategy for switching on or switching off a specific power tube by advancing or lagging a certain electric angle on the basis of standard three-phase three-state control, if: advance angle control, three-phase six-state control, three-phase nine-state control and the like.
However, the existing angle control strategy is still a current closed-loop control strategy in nature, and torque ripple is mainly generated by inductance nonlinearity and commutation follow current, so that the control on the current amplitude is difficult to generate a good torque ripple suppression effect. A torque closed loop is introduced into a motion control system, so that the torque pulsation of a motor can be well inhibited. The patent of "a torque control method for an electrically excited doubly salient motor" (application number: CN201811346348.0) published by zhuang et al proposes a structure of double closed-loop control of rotational speed and torque, which can directly perform closed-loop control on torque, but still has large phase-change torque ripple due to current afterflow after the state switching process. The patent application No. CN201911124214.9 discloses a control method for reducing torque ripple of an electro-magnetic doubly salient motor (by Toursei and the like), and provides a rotating speed torque current three-closed-loop control structure, which inhibits the torque ripple of non-commutation through a torque loop, and inhibits the torque ripple during commutation by combining a current inner loop, so that the torque ripple inhibition effect is good, but the calculation amount of the system is increased due to the relatively complex design and realization of a current distribution function.
Disclosure of Invention
The invention provides an electro-magnetic doubly salient motor control method for inhibiting torque pulsation based on torque closed loop aiming at the problems and technical requirements, and the technical scheme of the invention is as follows:
an electro-magnetic doubly salient motor control method for inhibiting torque pulsation based on torque closed loop comprises the following steps:
the motor rotor position theta of an electro-magnetic doubly salient motor and the phase current values i of three phase windings are adopteda、ib、icThe electro-magnetic doubly salient motor comprises a phase winding driven by a three-phase bridge type power circuit and an excitation winding driven by an asymmetric half-bridge type power circuit;
determining motor torque set value T corresponding to motor rotor position theta based on rotating speed regulatore *;
From the motor rotor position theta and the phase current values i of the three phase windingsa、ib、icDetermining a motor torque feedback value T by combining the first preset corresponding relationeThe first preset corresponding relation reflects the change relation of the three-phase torque value along with the position of the motor rotor and the phase current value;
according to the given value T of motor torquee *And motor torque feedback value TeGenerating a first control signal G having a predetermined duty cycle gamma0;
Determining a second control signal G corresponding to the motor rotor position theta according to a second preset corresponding relation1The second preset corresponding relation reflects second control signals corresponding to different motor rotor intervals, and the second control signals control the conduction state of each power tube;
by a first control signal G0And a second control signal G1And generating a driving signal G, and driving the states of all power tubes in the three-phase bridge type power circuit according to the driving signal G.
According to a further technical scheme, in the second preset corresponding relation, different motor rotor sections in one electric cycle are obtained by dividing on the basis of an advance conduction angle alpha, an advance commutation angle beta and a delay turn-off angle eta on the basis of three sectors, the advance conduction angle alpha, the advance commutation angle beta and the delay turn-off angle eta are determined on the basis of the relation among three-phase no-load back electromotive force of the electrically excited doubly salient motor, and each power tube in the three-phase bridge type power circuit has a corresponding conduction state in each motor rotor section.
The further technical scheme is that the method also comprises the following steps:
determining the no-load back-emf E of the phase-B winding where the first zero-crossing occurs in the three-phase no-load back-emfbZero-crossing point of (1) and no-load back-emf E of the second phase winding with zero-crossing pointaIs electrically angular difference theta between zero crossings of0Determining an advanced conduction angle α ═ k1*θ0;
Determining the no-load back-emf E of the phase A windingaNo-load counter-potential E with phase B windingbAnd the second zero-crossing point of the A-phase windingaIs electrically angular difference theta between zero crossings of1Determining the advanced commutation angle β ═ θ1;
Determining the no-load back-emf E of the phase A winding at the second occurrence of a zero crossingaZero-crossing point of (3) and the third zero-crossing point of the no-load counter potential E of the C-phase windingcIs electrically angular difference theta between zero crossings of3Determining the hysteresis turn-off angle eta k2*θ3;
Wherein, theta1/θ0<k1<1,θ2/θ3<k2<1,θ2No-load back-emf E of phase A winding indicating the second zero crossingaZero crossing point of (1) and no-load back electromotive force E of phase-A windingaAnd no-load back-emf E of the C-phase windingcThe electrical angle difference between the crossing points of (a).
The further technical proposal is that k is more than or equal to 1/21≤2/3,1/2≤k2≤2/3。
The further technical scheme is that on the basis of three sectors, a motor rotor interval and a corresponding power tube conduction state obtained by dividing based on an advance conduction angle alpha, an advance commutation angle beta and a lag off angle eta comprise:
(1)(360°-β,360°]∪(0°,η]within the interval, the power tube T6、T1、T2Conducting and switching off the rest;
(2)(η,120°-α]within the interval, the power tube T1、T2Conducting and switching off the rest;
(3)(120°-α,120°-β]within the interval, the power tube T1、T2、T3Conducting and switching off the rest;
(4)(120°-β,120°+η]within the interval, the power tube T2、T3、T4Conducting and switching off the rest;
(5)(120°+η,240°-α]within the interval, the power tube T3、T4Conducting and switching off the rest;
(6)(240°-α,240°-β]within the interval, the power tube T3、T4、T5Conducting and switching off the rest;
(7)(240°-β,240°+η]within the interval, the power tube T4、T5、T6Conducting and switching off the rest;
(8)(240°+η,360°-α]within the interval, the power tube T5、T6Conducting and switching off the rest;
(9)(360°-α,360°-β]within the interval, the power tube T5、T6、T1Conducting and switching off the rest;
wherein, T1、T4Upper and lower power tubes, T, of the first bridge arm3、T6Upper and lower power tubes, T, of the second arm5、T2Are the upper and lower power tubes of the third bridge arm.
The further technical scheme is that the method also comprises the following steps:
dividing the three sectors in an electrical cycle based on an advanced conduction angle alpha, an advanced commutation angle beta and a delayed turn-off angle eta to obtain an initial rotor interval;
if the conducting states of an upper power tube and a lower power tube of the same bridge arm in the three-phase bridge type power circuit are only switched when jumping from the previous initial rotor interval to the current initial rotor interval, continuously dividing the current initial rotor interval into a first subinterval and a second subinterval based on a preset dead zone angle delta, firstly switching off the conducted power tube on the corresponding bridge arm in the first subinterval, and then switching on the other power tube on the same bridge arm in the second subinterval;
and taking two subintervals obtained by dividing the initial rotor interval and other initial rotor intervals which are not further divided as the divided motor rotor interval.
The further technical scheme is that on the basis of three sectors, motor rotor intervals and corresponding power tube conduction states obtained by dividing the three sectors based on an advance conduction angle alpha, an advance commutation angle beta, a delay turn-off angle eta and a preset dead zone angle delta comprise:
(1)(360°-β+δ,360°]∪(0°,η]within the interval, the power tube T6、T1、T2Conducting and switching off the rest;
(2)(η,120°-α]within the interval, the power tube T1、T2Conducting and switching off the rest;
(3)(120°-α,120°-β]within the interval, the power tube T1、T2、T3Conducting and switching off the rest;
(4)(120°-β,120°-β+δ]within the interval, the power tube T2、T3Conducting and switching off the rest;
(5)(120°-β+δ,120°+η]within the interval, the power tube T2、T3、T4Conducting and switching off the rest;
(6)(120°+η,240°-α]within the interval, the power tube T3、T4Conducting and switching off the rest;
(7)(240°-α,240°-β]within the interval, the power tube T3、T4、T5Conducting and switching off the rest;
(8)(240°-β,240°-β+δ]within the interval, the power tube T4、T5Conducting and switching off the rest;
(9)(240°-β+δ,240°+η]within the interval, the power tube T4、T5、T6Conducting and switching off the rest;
(10)(240°+η,360°-α]within the interval, the power tube T5、T6Conducting and switching off the rest;
(11)(360°-α,360°-β]within the interval, the power tube T5、T6、T1Conducting and switching off the rest;
(12)(360°-β,360°-β+δ]within the interval, the power tube T6、T1Conducting and switching off the rest;
wherein, T1、T4Upper and lower power tubes, T, of the first bridge arm3、T6Upper and lower power tubes, T, of the second arm5、T2Are the upper and lower power tubes of the third bridge arm.
The further technical scheme is that a motor torque set value T corresponding to the position theta of the motor rotor is determined based on the rotating speed regulatore *The method comprises the following steps:
calculating to obtain a motor rotating speed feedback value n corresponding to the motor rotor position theta;
given value n of motor speed*Feeding the difference to a rotating speed regulator for PID control after making a difference with a motor rotating speed feedback value n, and taking the output of the rotating speed regulator as a motor torque set value Te *。
The further technical scheme is that the set value T is set according to the torque of the motore *And motor torque feedback value TeGenerating a first control signal G having a predetermined duty cycle gamma0The method comprises the following steps:
for given value T of motor torquee *And motor torque feedback value TeAfter difference is made, the difference is sent to a torque regulator for PID control, and the output of the torque regulator is used as a preset duty ratio gamma;
generating a first control signal G having a predetermined duty cycle gamma by a PWM generator0。
The further technical scheme is that the motor rotor position theta and the phase current values i of three phase windingsa、ib、icDetermining a motor torque feedback value T by combining the first preset corresponding relationeThe method comprises the following steps:
determining the position of the rotor of the motor from the first predetermined correspondenceAnd phase current values i of three phase windingsa、ib、icCorresponding three-phase torque value Ta、Tb、Tc;
For three-phase torque value Ta、Tb、TcSumming to obtain the torque feedback value T of the motore。
The beneficial technical effects of the invention are as follows:
the application discloses an electro-magnetic doubly salient motor control method for inhibiting torque pulsation based on a torque closed loop. In addition, according to the inductance curve and the no-load back electromotive force curve of the motor, a specific conduction mode and a specific control angle are selected, and torque pulsation can be well inhibited in the phase commutation and non-phase commutation stages. The circuit safety can be effectively ensured and the same bridge arm can be prevented from being directly connected by setting a specific dead zone mode, and the dead zone mode basically has no influence on the output torque of the motor and cannot reduce the output torque of the motor due to the follow current process of phase current when the motor is phase-changed.
Drawings
Fig. 1 is a topological diagram of an electrically excited doubly salient machine and a power circuit according to the present application.
Fig. 2 is a graph of motor self inductance and mutual inductance for the electrically excited doubly salient motor of fig. 1.
Fig. 3 is a control logic schematic diagram of the electro-magnetic doubly salient motor control method of the present application.
Fig. 4 is a schematic diagram of determining the advance conduction angle α, the advance commutation angle β, and the retard turn-off angle η based on the three-phase no-load back emf.
Fig. 5 is a schematic diagram of a motor rotor interval divided based on the advance conduction angle α, the advance commutation angle β, and the retard conduction angle η on the basis of three sectors, and the conduction states of the respective power tubes.
Fig. 6 is a simulated waveform diagram of motor phase currents in one example.
Fig. 7 is a simulated waveform diagram of motor output torque in one example.
Detailed Description
The following further describes the embodiments of the present invention with reference to the drawings.
The application discloses an electro-magnetic doubly salient motor control method for restraining torque pulsation based on torque closed loop, wherein an electro-magnetic doubly salient motor and a power circuit topological diagram in the method are shown in figure 1, and the electro-magnetic doubly salient motor comprises a phase winding A, B, C driven by a three-phase bridge type power circuit and an excitation winding F driven by an asymmetric half-bridge type power circuit. The three-phase bridge power circuit comprises three bridge arms consisting of six power tubes, T1、T4Upper and lower power tubes, T, of the first bridge arm3、T6Upper and lower power tubes, T, of the second arm5、T2The power tube is an upper power tube and a lower power tube of a third bridge arm, the middle point of the first bridge arm is led out and connected with an A-phase winding, the middle point of the second bridge arm is led out and connected with a B-phase winding, the middle point of the third bridge arm is led out and connected with a C-phase winding, and the other ends of the three phase windings are connected. In an electrically excited doubly salient machine of the construction shown in fig. 1, the self-inductance L of the phase winding isa、Lb、LcAnd mutual inductance L between the phase winding and the excitation windingaf、Lbf、LcfThe variation with the motor rotor position theta is shown in figure 2.
Based on the structure shown in fig. 1, a control logic diagram of the control method of the present application is shown in fig. 3, and the method includes:
1. the motor rotor position theta of an electro-magnetic doubly salient motor and the phase current values i of three phase windings are adopteda、ib、ic. The motor rotor position θ may be obtained by a photoelectric encoder mounted coaxially with the motor rotor. Value of phase current ia、ib、icThis can be achieved by a current hall sensor mounted to the motor phase winding.
2. Determining motor torque set value T corresponding to motor rotor position theta based on rotating speed regulatore *. Firstly, after the position theta of the motor rotor is obtained, the motor rotating speed feedback value n corresponding to the position theta of the motor rotor can be obtained through calculation, and then the motor is rotatedSpeed set value n*Feeding the difference to a rotating speed regulator for PID control after making a difference with a motor rotating speed feedback value n, and taking the output of the rotating speed regulator as a motor torque set value Te *The direct control of the motor torque is realized by adjusting the set value of the motor torque. Wherein the given value n of the motor speed*May be a custom value.
3. From the motor rotor position theta and the phase current values i of the three phase windingsa、ib、icDetermining a motor torque feedback value T by combining the first preset corresponding relatione。
The first preset corresponding relation reflects the change relation of a three-phase torque value along with the position and the phase current value of the motor rotor, and is the corresponding relation obtained by fitting sampling data in advance, a torque sensor is installed on a motor shaft, an electrically excited doubly salient motor is controlled to operate in different states, and multiple groups of sampling data are obtained, each group of sampling data comprises the three-phase torque value obtained by sampling the torque sensor, the phase current value obtained by sampling the current Hall sensor and the position of the motor rotor obtained by sampling the photoelectric encoder, and the first preset corresponding relation, namely a torque-current-position table, is obtained by fitting the multiple groups of sampling data.
In one embodiment, since the first preset corresponding relationship obtained by fitting is three-phase torque, the first preset corresponding relationship is used for determining the position of the motor rotor and the phase current values i of three phase windingsa、ib、icCorresponding three-phase torque value Ta、Tb、TcThen for three-phase torque value Ta、Tb、TcSumming to obtain the torque feedback value T of the motoreActually, the three-phase torque value can be directly summed during fitting and then fitted, and the application does not limit the sum.
4. According to the given value T of motor torquee *And motor torque feedback value TeGenerating a first control signal G having a predetermined duty cycle gamma0. In particular, for a given value of motor torque Te *And motor torque feedback value TeMake difference and then send into torque regulatorPID control is performed to output the torque regulator as a predetermined duty ratio gamma, and a PWM generator generates a first control signal G having the predetermined duty ratio gamma0。
5. Determining a second control signal G corresponding to the motor rotor position theta according to a second preset corresponding relation1And the second preset corresponding relation reflects second control signals corresponding to different motor rotor intervals, and the second control signals control the conduction state of each power tube in the three-phase bridge type power circuit.
In the second preset corresponding relation, different motor rotor intervals in one electrical cycle are obtained by dividing on the basis of an advance conduction angle alpha, an advance commutation angle beta and a delay turn-off angle eta on the basis of three sectors, wherein the three sectors in one electrical cycle are respectively (0 degrees, 120 degrees), (120 degrees, 240 degrees) and (240 degrees, 360 degrees), the position where the motor rotor is opposite to the stator pole of the C-phase winding is taken as an initial position, the pole tip of the motor rotor is aligned with the pole tip of the A-phase stator and is about to slide in, and the electrical angle is defined as 0 degree.
The advance conduction angle alpha, the advance commutation angle beta and the delay turn-off angle eta are determined based on the relation among three-phase no-load back electromotive forces of the electro-magnetic doubly salient motor, and each power tube in the three-phase bridge type power circuit has a corresponding conduction state in each motor rotor region.
The method for determining the respective control angles alpha, beta and eta in the electro-magnetic doubly salient motor control system comprises the following steps: dragging the electric excitation double-salient-pole motor by a prime motor to measure the three-phase no-load back electromotive force E of the electric excitation double-salient-pole motora、Eb、EcPlease refer to the curve diagram of the three-phase no-load back electromotive force shown in fig. 4:
determining the no-load back-emf E of the phase-B winding where the first zero-crossing occurs in the three-phase no-load back-emfbZero-crossing point of (1) and no-load back-emf E of the second phase winding with zero-crossing pointaIs electrically angular difference theta between zero crossings of0Determining an advanced conduction angle α ═ k1*θ0。
Determining the no-load back-emf E of the phase A windingaNo-load counter-potential E with phase B windingbCross point of (2) and secondNo-load counter-potential E of phase a winding with zero crossingaIs electrically angular difference theta between zero crossings of1Determining the advanced commutation angle β ═ θ1。
Determining the no-load back-emf E of the phase A winding at the second occurrence of a zero crossingaZero-crossing point of (3) and the third zero-crossing point of the no-load counter potential E of the C-phase windingcIs electrically angular difference theta between zero crossings of3Determining the hysteresis turn-off angle eta k2*θ3。
Coefficient theta for determining advance conduction angle alpha as described above1/θ0<k1<1, coefficient theta for determining hysteresis shutdown angle eta2/θ3<k2<1,θ2No-load back-emf E of phase A winding indicating the second zero crossingaZero crossing point of (1) and no-load back electromotive force E of phase-A windingaAnd no-load back-emf E of the C-phase windingcThe electrical angle difference between the crossing points of (a) as shown in fig. 4. In one embodiment, 1/2 ≦ k1≤2/3,1/2≤k2≤2/3。
In one embodiment, referring to the schematic diagram of the variation of each power tube with the rotor position θ of the motor shown in fig. 5, the motor rotor interval and the corresponding power tube conduction state obtained by dividing the motor rotor interval based on the advance conduction angle α, the advance commutation angle β and the retard off-angle η on the basis of three sectors includes:
(1)(360°-β,360°]∪(0°,η]within the interval, the power tube T6、T1、T2And the A-phase winding is conducted positively, the B-phase winding is conducted negatively, and the C-phase winding is conducted negatively.
(2)(η,120°-α]Within the interval, the power tube T1、T2And conducting and turning off the rest of the windings, wherein the A-phase winding is conducted in the positive direction and the C-phase winding is conducted in the negative direction.
(3)(120°-α,120°-β]Within the interval, the power tube T1、T2、T3And the conduction and the rest are switched off, and at the moment, the A-phase winding is conducted positively, the B-phase winding is conducted positively, and the C-phase winding is conducted negatively.
(4)(120°-β,120°+η]Within the interval, the power tube T2、T3、T4And conducting and turning off the rest of the windings, wherein the A-phase winding is conducted in the negative direction, the B-phase winding is conducted in the positive direction, and the C-phase winding is conducted in the negative direction.
(5)(120°+η,240°-α]Within the interval, the power tube T3、T4And conducting and turning off the rest of the windings, wherein the A-phase winding is conducted in the negative direction and the B-phase winding is conducted in the positive direction.
(6)(240°-α,240°-β]Within the interval, the power tube T3、T4、T5And the conduction is carried out, and the rest of the windings are switched off, at the moment, the A-phase winding is conducted in the negative direction, the B-phase winding is conducted in the positive direction, and the C-phase winding is conducted in the positive direction.
(7)(240°-β,240°+η]Within the interval, the power tube T4、T5、T6And the conduction and the rest are switched off, at the moment, the winding of the phase A is conducted in the negative direction, the winding of the phase B is conducted in the negative direction, and the winding of the phase C is conducted in the positive direction.
(8)(240°+η,360°-α]Within the interval, the power tube T5、T6And conducting, and turning off the rest, wherein the B-phase winding is conducted in the negative direction, and the C-phase winding is conducted in the positive direction.
(9)(360°-α,360°-β]Within the interval, the power tube T5、T6、T1And the conduction and the rest are switched off, at the moment, the A-phase winding is conducted positively, the B-phase winding is conducted negatively, and the C-phase winding is conducted positively.
In another embodiment, in order to ensure the circuit safety and avoid the same bridge arm from being directly connected, after the method divides the three sectors in one electrical cycle based on the advanced conduction angle α, the advanced commutation angle β and the delayed turn-off angle η to obtain 9 initial rotor intervals as in the above embodiment, the method further comprises the following operations: if the conducting states of the upper power tube and the lower power tube of the same bridge arm in the three-phase bridge type power circuit are only switched when the previous initial rotor interval jumps to the current initial rotor interval, the current initial rotor interval is continuously divided into a first subinterval and a second subinterval based on a preset dead zone angle delta, the conducted power tubes on the corresponding bridge arm are firstly turned off in the first subinterval, and the other power tubes on the same bridge arm are then conducted in the second subinterval. Two subintervals obtained by dividing the initial rotor interval and other initial rotor intervals which are not further divided are taken as the divided motor rotor intervals, and the specific electrical angle value of the preset dead zone angle delta can be configured by self, for example, the value can be 1-3 degrees generally.
For example, in 9 initial rotor intervals obtained by the division, the number of the rotor intervals is from (120-alpha, 120-beta)]The interval jumps to (120 degrees to beta, 120 degrees to eta]In the interval, the power tube T1、T2、T3Conducting and switching to the power tube T2、T3、T4Conducting, only switching the upper and lower power tubes T on the first bridge arm1、T4In order to prevent the first bridge arm from straight-through, a preset dead zone angle delta is added (120 degrees to beta, 120 degrees to eta)]Is divided into two parts, T is firstly arranged in a first subinterval1Turning off, and turning on T again in the second subinterval4And conducting. Similarly, also from (240-alpha, 240-beta)]The interval jumps to (240-beta, 240-eta)]In the interval, and from (360 ° - α,360 ° - β)]The interval jumps to (360-beta, 360-degree) of the next electrical cycle]∪(0°,η]This operation is required for both intervals. Therefore, on the basis of the three sectors, the motor rotor interval and the corresponding power tube conduction state obtained by dividing the motor rotor interval based on the advance conduction angle alpha, the advance commutation angle beta, the delay turn-off angle eta and the preset dead zone angle delta comprise:
(1)(360°-β+δ,360°]∪(0°,η]within the interval, the power tube T6、T1、T2And the A-phase winding is conducted positively, the B-phase winding is conducted negatively, and the C-phase winding is conducted negatively.
(2)(η,120°-α]Within the interval, the power tube T1、T2And conducting and turning off the rest of the windings, wherein the A-phase winding is conducted in the positive direction and the C-phase winding is conducted in the negative direction.
(3)(120°-α,120°-β]Within the interval, the power tube T1、T2、T3And the conduction and the rest are switched off, and at the moment, the A-phase winding is conducted positively, the B-phase winding is conducted positively, and the C-phase winding is conducted negatively.
(4)(120°-β,120°-β+δ]Within the interval, the power tube T2、T3And conducting and turning off the rest of the windings, wherein the winding of the B phase is conducted in the positive direction, and the winding of the C phase is conducted in the negative direction.
(5)(120°-β+δ,120°+η]Within the interval, the power tube T2、T3、T4And conducting and turning off the rest of the windings, wherein the A-phase winding is conducted in the negative direction, the B-phase winding is conducted in the positive direction, and the C-phase winding is conducted in the negative direction.
(6)(120°+η,240°-α]Within the interval, the power tube T3、T4And conducting and turning off the rest of the windings, wherein the A-phase winding is conducted in the negative direction and the B-phase winding is conducted in the positive direction.
(7)(240°-α,240°-β]Within the interval, the power tube T3、T4、T5And the conduction is carried out, and the rest of the windings are switched off, at the moment, the A-phase winding is conducted in the negative direction, the B-phase winding is conducted in the positive direction, and the C-phase winding is conducted in the positive direction.
(8)(240°-β,240°-β+δ]Within the interval, the power tube T4、T5And conducting and turning off the rest of the windings, wherein the A-phase winding is conducted in the negative direction and the C-phase winding is conducted in the positive direction.
(9)(240°-β+δ,240°+η]Within the interval, the power tube T4、T5、T6And the conduction and the rest are switched off, at the moment, the winding of the phase A is conducted in the negative direction, the winding of the phase B is conducted in the negative direction, and the winding of the phase C is conducted in the positive direction.
(10)(240°+η,360°-α]Within the interval, the power tube T5、T6And conducting, and turning off the rest, wherein the B-phase winding is conducted in the negative direction, and the C-phase winding is conducted in the positive direction.
(11)(360°-α,360°-β]Within the interval, the power tube T5、T6、T1And the conduction and the rest are switched off, at the moment, the A-phase winding is conducted positively, the B-phase winding is conducted negatively, and the C-phase winding is conducted positively.
(12)(360°-β,360°-β+δ]Within the interval, the power tube T6、T1And the A-phase winding is conducted positively, and the B-phase winding is conducted negatively.
6. By a first control signal G0And a second control signal G1And generating a driving signal G, and driving the states of all power tubes in the three-phase bridge type power circuit according to the driving signal G. In one embodiment, the first control signal G0And a second control signal G1And performing logical AND to generate a driving signal G.
The purpose of directly controlling the output torque of the motor can be achieved through the control method disclosed by the application, so that torque pulsation is inhibited, and the motor runs stably. In order to verify the effectiveness of the method, Matlab/Simulink simulation is carried out on 12/8 electromechanical excitation doubly salient motor, wherein motor inductance parameters are obtained by finite element simulation and are fitted to obtain a nonlinear inductance model, and a coefficient k corresponding to an advanced conduction angle alpha is set11/2, coefficient k corresponding to the hysteresis turn-off angle η 22/3. The simulation conditions were as follows: the speed was given as 700rpm, the torque limit was 6N · m, and the current limit was 30A. The starting process is a load starting with 2N · m, and after the motor runs smoothly, the load of 4N · m is suddenly added when t is 0.1s, and the waveforms of the phase current and the output torque of the motor in the whole process are shown in fig. 6 and 7. As can be seen from fig. 6 and 7, the torque ripple of the commutation and non-commutation phases can be effectively suppressed by the control method provided by the present application. In a non-commutation stage, the phase current amplitude is not constant, and certain distortion is generated so as to inhibit torque pulsation caused by nonlinearity of an inductor; and in the phase change stage, the positive current of the next phase is switched on by advancing, and the negative current of the current phase is switched off by delaying, so that each phase of current is at the moment when the phase torque output is small during phase change, and the torque pulsation caused by the follow current of the phase of current is suppressed.
What has been described above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiment. It is to be understood that other modifications and variations directly derivable or suggested by those skilled in the art without departing from the spirit and concept of the present invention are to be considered as included within the scope of the present invention.
Claims (8)
1. An electro-magnetic doubly salient motor control method for torque ripple suppression based on torque closed loop is characterized by comprising the following steps:
the motor rotor position theta of an electro-magnetic doubly salient motor and the phase current values i of three phase windings are adopteda、ib、icThe doubly salient electro-magnetic motor comprises a phase winding driven by a three-phase bridge power circuit and is driven by an asymmetric half-bridge power circuitA moving field winding;
determining a motor torque set value T corresponding to the motor rotor position theta based on a rotating speed regulatore *;
The phase current value i of three phase windings and the position theta of the motor rotora、ib、icDetermining a motor torque feedback value T by combining the first preset corresponding relationeThe first preset corresponding relation reflects the change relation of the three-phase torque value along with the position of the motor rotor and the phase current value;
according to the set value T of the motor torquee *And the motor torque feedback value TeGenerating a first control signal G having a predetermined duty cycle gamma0;
Determining a second control signal G corresponding to the motor rotor position theta according to a second preset corresponding relation1The second preset corresponding relation reflects second control signals corresponding to different motor rotor intervals, and the second control signals indicate the conduction state of each power tube;
by the first control signal G0And said second control signal G1Generating a driving signal G after carrying out logical AND, and driving the states of all power tubes in the three-phase bridge type power circuit according to the driving signal G;
in the second preset corresponding relation, different motor rotor sections in one electrical cycle are obtained by dividing on the basis of an advance conduction angle alpha, an advance commutation angle beta and a delay turn-off angle eta on the basis of three sectors, the advance conduction angle alpha, the advance commutation angle beta and the delay turn-off angle eta are determined on the basis of the relation among three-phase no-load back electromotive force of the electrically excited doubly salient motor, and each power tube in the three-phase bridge type power circuit has a corresponding conduction state in each motor rotor section; on the basis of the three sectors, the motor rotor interval and the corresponding power tube conduction state obtained by dividing based on the advance conduction angle alpha, the advance commutation angle beta and the lag off-angle eta comprise:
(1)(360°-β,360°]∪(0°,η]within the interval, the power tube T6、T1、T2Conducting and switching off the rest;
(2)(η,120°-α]within the interval, the power tube T1、T2Conducting and switching off the rest;
(3)(120°-α,120°-β]within the interval, the power tube T1、T2、T3Conducting and switching off the rest;
(4)(120°-β,120°+η]within the interval, the power tube T2、T3、T4Conducting and switching off the rest;
(5)(120°+η,240°-α]within the interval, the power tube T3、T4Conducting and switching off the rest;
(6)(240°-α,240°-β]within the interval, the power tube T3、T4、T5Conducting and switching off the rest;
(7)(240°-β,240°+η]within the interval, the power tube T4、T5、T6Conducting and switching off the rest;
(8)(240°+η,360°-α]within the interval, the power tube T5、T6Conducting and switching off the rest;
(9)(360°-α,360°-β]within the interval, the power tube T5、T6、T1Conducting and switching off the rest;
wherein, T1、T4Upper and lower power tubes, T, of the first bridge arm3、T6Upper and lower power tubes, T, of the second arm5、T2Are the upper and lower power tubes of the third bridge arm.
2. The method of claim 1, further comprising:
determining the no-load back-emf E of the phase-B winding where the first zero-crossing occurs in the three-phase no-load back-emfbZero-crossing point of (1) and no-load back-emf E of the second phase winding with zero-crossing pointaIs electrically angular difference theta between zero crossings of0Determining an advanced conduction angle α ═ k1*θ0;
Determining the no-load back-emf E of the phase A windingaAnd no-load back-emf E of the B-phase windingbAnd the second zero crossing point of the A-phase windingCarrying counter potential EaIs electrically angular difference theta between zero crossings of1Determining the advanced commutation angle β ═ θ1;
Determining the no-load back-emf E of the phase A winding at the second occurrence of a zero crossingaZero-crossing point of (3) and the third zero-crossing point of the no-load counter potential E of the C-phase windingcIs electrically angular difference theta between zero crossings of3Determining the hysteresis turn-off angle eta k2*θ3;
Wherein, theta1/θ0<k1<1,θ2/θ3<k2<1,θ2No-load back-emf E of phase A winding indicating the second zero crossingaZero crossing point of (1) and no-load back electromotive force E of phase-A windingaAnd no-load back-emf E of the C-phase windingcThe electrical angle difference between the crossing points of (a).
3. The method of claim 2, wherein 1/2 ≦ k1≤2/3,1/2≤k2≤2/3。
4. The method according to any one of claims 1-3, further comprising:
dividing the three sectors in an electrical cycle based on an advanced conduction angle alpha, an advanced commutation angle beta and a delayed turn-off angle eta to obtain an initial rotor interval;
if the conducting states of an upper power tube and a lower power tube of the same bridge arm in the three-phase bridge type power circuit are only switched when jumping from the previous initial rotor interval to the current initial rotor interval, continuously dividing the current initial rotor interval into a first subinterval and a second subinterval based on a preset dead zone angle delta, firstly switching off the conducted power tube on the corresponding bridge arm in the first subinterval, and then switching on another power tube on the same bridge arm in the second subinterval;
and taking two subintervals obtained by dividing the initial rotor interval and other initial rotor intervals which are not further divided as the divided motor rotor interval.
5. The method of claim 4 wherein dividing the motor rotor interval and corresponding power tube conduction state based on the advance conduction angle α, the advance commutation angle β, the retard turn-off angle η, and the preset dead band angle δ on a three sector basis comprises:
(1)(360°-β+δ,360°]∪(0°,η]within the interval, the power tube T6、T1、T2Conducting and switching off the rest;
(2)(η,120°-α]within the interval, the power tube T1、T2Conducting and switching off the rest;
(3)(120°-α,120°-β]within the interval, the power tube T1、T2、T3Conducting and switching off the rest;
(4)(120°-β,120°-β+δ]within the interval, the power tube T2、T3Conducting and switching off the rest;
(5)(120°-β+δ,120°+η]within the interval, the power tube T2、T3、T4Conducting and switching off the rest;
(6)(120°+η,240°-α]within the interval, the power tube T3、T4Conducting and switching off the rest;
(7)(240°-α,240°-β]within the interval, the power tube T3、T4、T5Conducting and switching off the rest;
(8)(240°-β,240°-β+δ]within the interval, the power tube T4、T5Conducting and switching off the rest;
(9)(240°-β+δ,240°+η]within the interval, the power tube T4、T5、T6Conducting and switching off the rest;
(10)(240°+η,360°-α]within the interval, the power tube T5、T6Conducting and switching off the rest;
(11)(360°-α,360°-β]within the interval, the power tube T5、T6、T1Conducting and switching off the rest;
(12)(360°-β,360°-β+δ]within the interval, the power tube T6、T1Conducting and switching off the rest;
wherein, T1、T4Upper and lower power tubes, T, of the first bridge arm3、T6Upper and lower power tubes, T, of the second arm5、T2Are the upper and lower power tubes of the third bridge arm.
6. The method of claim 1, wherein the speed regulator-based determination of the motor torque setpoint T for the motor rotor position θe *The method comprises the following steps:
calculating to obtain a motor rotating speed feedback value n corresponding to the motor rotor position theta;
given value n of motor speed*Feeding the difference to the rotating speed regulator for PID control after making a difference with the rotating speed feedback value n of the motor, and taking the output of the rotating speed regulator as the set value T of the motor torquee *。
7. Method according to claim 1, characterized in that said given value T is a function of said motor torquee *And the motor torque feedback value TeGenerating a first control signal G having a predetermined duty cycle gamma0The method comprises the following steps:
for the given value T of the motor torquee *And the motor torque feedback value TeAfter difference is made, the difference is sent to a torque regulator for PID control, and the output of the torque regulator is used as the preset duty ratio gamma;
generating a first control signal G having said predetermined duty cycle gamma by a PWM generator0。
8. The method of claim 1, wherein the phase current values i for three phase windings and the motor rotor position θ are determined from the motor rotor position θa、ib、icDetermining a motor torque feedback value T by combining the first preset corresponding relationeThe method comprises the following steps:
determining the position of the motor rotor and phase current values i of three phase windings according to the first preset corresponding relationa、ib、icCorresponding three-phase torqueValue Ta、Tb、Tc;
For three-phase torque value Ta、Tb、TcSumming to obtain the motor torque feedback value Te。
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