CN101594114A - Method for determining initial position angle of rotor of permanent magnet synchronous motor - Google Patents

Abstract

Method for determining initial position angle of rotor of permanent magnet synchronous motor, belong to Motor Control Field, the present invention be for the detection method that solves original position of electric motor's rotator in the AC servo and the rotor detection method that provides of device patent exist logic determines complicated, detect the easily problem of failure.The present invention utilizes the d under the control two synchronised rotary axis, the amplitude and the phase place of q shaft current, and then the amplitude and the phase place of the threephase stator electric current under the control three phase static axle system, the rotation of control rotor under given stator field, pulse signal according to the incremental encoder feedback, given magnetic direction is circulated gradually approach actual rotor position angle, up to the stator field direction and the coincidence of rotor field direction of given d, q shaft current correspondence.Given stator current magnetic direction changes 90 degree, to produce a torque perpendicular to the rotor field direction, according to the rotation direction of rotor, finally judges the initial position angle of actual rotor on rotor.

Description

Method for determining initial position angle of rotor of permanent magnet synchronous motor

Technical field

The present invention relates to a kind of method for determining initial position angle of rotor of permanent magnet synchronous motor, belong to Motor Control Field.

Background technology

Need accurate position, speed feedback information in the AC servo.Its position detection unit is the assurance of system accuracy as feedback device.On the one hand, it provides coordinate transform necessary positional information for system's vector control; In positional servosystem, provide position feedback for position ring.On the other hand, because machinery is installed and the cost problem, servo system generally no longer is furnished with velocity transducer, but estimates tachometer value from positional information.Therefore, rotor position information plays considerable effect in servo system.

In permanent magnet synchronous motor, position transducer generally adopts elements such as high-resolution resolver, photoelectric encoder, magnetic coder.Resolver output two-phase orthogonal waveforms, the absolute position of energy output rotor, but its decoding circuit complexity costs an arm and a leg.Magnetic coder relies on the pole change detection position, is in conceptual phase at present, and its resolution is lower.Photoelectric encoder is divided into absolute type and increment type, than other detecting element direct output digital quantity signal is arranged, and inertia is low, low noise, and high accuracy, high-resolution, simple for production, low cost and other advantages.The Gray code absolute type encoder is generally all made the circulation binary code, and code channel road number is identical with number of bits.The Gray code absolute type encoder is the absolute position of output rotor directly, does not need to measure initial position.But its complex process, cost height.The absolute type encoder precision that adopts on the general AC servo is generally between 12 to 20.Incremental encoder is simple in structure, makes easily, generally carves A, B, the equally distributed groove in Z three roads on code-disc, and the A of exportable quadrature, B delta pulse are represented the positional increment of rotor; The Z pulse then is that rotor whenever rotates a circle out one, generally the adjustment of Z pulse outgoing position is corresponded on the rotor N utmost point magnetic pole.Implementing vector control needs the absolute location information of rotor, and incremental encoder need cooperate the Z pulse could obtain absolute location information, and rotor-position is at random when initially powering on, and needs to determine initial position of rotor.The servo system that is equipped with incremental encoder obtains the initial position of rotor prior art and mainly contains:

(1) incremental encoder is installed on rotor, encoder output A, B, Z, U, 6 road pulse signals such as V, W, wherein A, B pulse signal are mutually orthogonal, and the phase place and the frequency of A, B pulse can be represented turning to of rotor and rotating speed.The rotor Z pulse signal of encoder output that whenever rotates a circle, the electrical degree position of determining on the Z pulse respective rotor.U, V, W pulse differ 120 degree electrical degrees on phase place, by judge the state of U, V, W signal at the initial stage that powers on, can obtain the initial position of rotor.

Chinese patent: adopt definite method (publication number is CN101409523) of the permanent magnet motor magnetic pole initial position of incremental encoder to propose further perfect solution, after system powers on, U/V/W signal condition according to the incremental encoder feedback, judge the residing position angle of rotor, estimate that according to this angle is by the rotation of driver control motor.But this method is to the error of ± 30 ° of electrical degrees of existence on the estimation theory of initial position angle, and needs increase Hall element could be exported U, V, W three road signals, system cost height.

(2) for the incremental encoder of installing on the rotor, under the situation that does not have U, V, W pulse output, when switching on first in system, the absolute position of rotor is uncertain.Can only allow motor rotation earlier, system's output stator electric current makes the motor open loop rotate, and when turning to controller when receiving the Z pulse that encoder sends here, controller could be confirmed the initial position of rotor according to the rotor electrical degree value of Z pulse correspondence.

This method need be when motor powers on first, the open loop rotation of motor elder generation, and the angular range of rotation is uncertain, and the mechanical angle that rotor may need to turn over 360 degree just can search out zero point, receives the Z pulse of encoder, and beginning is control normally.Incremental encoder can not provide the position signalling of rotor before this, this problem with regard to having caused motor to be difficult to start.Generally do not allow the open loop of rotor elder generation to rotate, like this for the difficulty that becomes of determining of initial position of rotor.

(3) Chinese patent: the detection method of original position of electric motor's rotator and device in the AC servo (publication number CN1148168A) have proposed a kind of method of detection rotor initial position, amplitude and phase place by direct control stator three-phase current, to produce the stator field of different directions, the rotation of control rotor, the magnetic direction that stator current is produced progressively approaches the rotor field direction.But circulation approaches angle in this method definite need to judge before and after the rotation information of twice (this and last time), logic determines is complicated, owing to just rotate this extreme case of a line by detecting encoder, very easily be interfered, there are vibrations or have in system to occur detecting error under the external interference situation probably, prolong sense cycle even cause the detection failure of initial position of rotor.

Summary of the invention

The objective of the invention is to solve the detection method of original position of electric motor's rotator in the AC servo and install patent the rotor detection method that provides and have the problem that logic determines is complicated, detect easy failure, a kind of method for determining initial position angle of rotor of permanent magnet synchronous motor is provided.

Method of the present invention may further comprise the steps:

Step 1, the following variate-value of initialization:

The q shaft current i of permanent-magnetic synchronous motor stator _q=0, the d shaft current i of permanent-magnetic synchronous motor stator _d=0, make k=0, rotor given position angle θ _e(k)=θ _e(0)=0,

Step 2, with the q shaft current i of permanent-magnetic synchronous motor stator _qIncrease Δ i _q, i.e. i _q=i _q+ Δ i _q, Δ i _qBe q shaft current increment value, Δ i _qGet the q shaft current amplitude limit value i of permanent-magnetic synchronous motor stator _{Q max}1%～5%,

Step 3, judge whether the i that satisfies condition _q〉=i _{Q max},

Judged result is for being, execution in step 11, judged result be not for, execution in step four,

Step 4, make the given current i of q axle _Qref=i _q, the given electric i of d axle _Dref=i _d, with the given current i of q axle under the two synchronised rotary axis _QrefWith the given current i of d axle _DrefBe transformed into the threephase stator current i under the three phase static axle system _a, i _bAnd i _c, adopt SVPWM Control Method output threephase stator current i _a, i _bAnd i _cThe control permagnetic synchronous motor is set up stator field, drives rotor to rotor given position angle θ _e(k) direction rotation,

Step 5, judge the permagnetic synchronous motor m line that whether turned clockwise, wherein setting m is that permagnetic synchronous motor allows the rotational line number: m gets 5 lines～10 lines,

Judged result is for being, execution in step eight, judged result be not for, execution in step six,

Step 6, judge whether permagnetic synchronous motor has been rotated counterclockwise the m line,

Judged result is for being, execution in step seven, judged result be not for, and permagnetic synchronous motor execution in step two, provides next rotor given position angle at step 7 ${\mathrm{\θ}}_e(k+1)={\mathrm{\θ}}_e\left(k\right)-\frac{\mathrm{\π}}{2^{k+1}},$ Execution in step nine then,

Step 8, provide next rotor given position angle ${\mathrm{\θ}}_e(k+1)={\mathrm{\θ}}_e\left(k\right)+\frac{\mathrm{\π}}{2^{k+1}},$ Execution in step nine then,

Step 9, judge whether to satisfy condition $\frac{\mathrm{\&pi;}}{2^{k+1}}<\mathrm{\&alpha;},$ Wherein, α is that precision allow to increase angle: and 0.5 °＜α＜1 °, judged result is for being, execution in step 11, judged result be for denying, execution in step ten,

The q shaft current i of step 10, the permanent-magnetic synchronous motor stator that resets _q=0, make k=k+1, execution in step two then;

Step 11, initial position angle of rotor be the value of declaring θ just _e(first)=θ _e(k),

Step 12, with rotor given position angle θ _e(k) be rotated counterclockwise 90 degree, produce a torque perpendicular to the rotor field direction,

Step 13, make i _Qref=i _{Q max}* p%, i _Dref=0, according to i _QrefAnd i _Dref, and adopt SVPWM Control Method control output stator electric current to set up stator field, drive rotor to rotor given position angle θ _e(k) direction rotation,

Wherein, p% gets the q shaft current amplitude limit value i of permanent-magnetic synchronous motor stator _{Q max}2%～5%,

Step 14, judge permagnetic synchronous motor 1 line that whether turns clockwise,

Judged result is not for, and execution in step 15, judged result be for being, execution in step 16,

Step 15, obtain initial position angle of rotor θ _e(initial)=θ _e(fisrt),

Step 10 six, obtain initial position angle of rotor θ _e(initial)=θ _e(fisrt)+π.

Advantage of the present invention:

1, the basis for estimation of stator current output phase is only changed into by this rotation information by front and back 2 times (last time and this) rotation information, and logic is more clear, and has improved the reliability of judging;

When 2, avoiding only approaching rotor-position by this rotation information foundation, 180 ° of electrical degree polarity of identifying position inverse case is accelerated positioning time;

3, rotate judgement information and change into and can set rotational pulse quantity arbitrarily, when guaranteeing reliable starting, strengthened vulnerability to jamming by the outside by the maximum conditions of 1 delta pulse only.

4, electric system carries or has under the vibrations condition also an initial alignment fast at band.

Description of drawings

Fig. 1 is the flow chart of the inventive method, and Fig. 2 is the schematic diagram of two synchronised rotary axis and three phase static axle system, and Fig. 3 is the structural representation of AC servo, and Fig. 4 is a theory diagram of realizing the AC servo drive system of the inventive method.

Embodiment

Embodiment one: below in conjunction with Fig. 1 to Fig. 4 present embodiment is described, this method of present embodiment may further comprise the steps:

Step 1, the following variate-value of initialization:

The q shaft current i of permanent-magnetic synchronous motor stator _q=0, the d shaft current i of permanent-magnetic synchronous motor stator _d=0, make k=0, rotor given position angle θ _e(k)=θ _e(0)=0,

Step 2, with the q shaft current i of permanent-magnetic synchronous motor stator _qIncrease Δ i _q, i.e. i _q=i _q+ Δ i _q, Δ i _qBe q shaft current increment value, Δ i _qGet the q shaft current amplitude limit value i of permanent-magnetic synchronous motor stator _{Q max}1%～5%,

Step 3, judge whether the i that satisfies condition _q〉=i _{Q max},

Judged result is for being, execution in step 11, judged result be not for, execution in step four,

Step 4, make the given current i of q axle _Qref=i _q, the given electric i of d axle _Dref=i _d, with the given current i of q axle under the two synchronised rotary axis _QrefWith the given current i of d axle _DrefBe transformed into the threephase stator current i under the three phase static axle system _a, i _bAnd i _c, adopt SVPWM Control Method (SVPWM) output threephase stator current i _a, i _bAnd i _cThe control permagnetic synchronous motor is set up stator field, drives rotor to rotor given position angle θ _e(k) direction rotation,

Step 5, judge the permagnetic synchronous motor m line that whether turned clockwise, wherein setting m is that permagnetic synchronous motor allows the rotational line number: m gets 5 lines～10 lines,

Judged result is for being, execution in step eight, judged result be not for, execution in step six,

Step 6, judge whether permagnetic synchronous motor has been rotated counterclockwise the m line,

Judged result is for being, execution in step seven, and judged result illustrates that for not permagnetic synchronous motor does not rotate, permagnetic synchronous motor execution in step two,

Step 7, provide next rotor given position angle ${\mathrm{\&theta;}}_e(k+1)={\mathrm{\&theta;}}_e\left(k\right)-\frac{\mathrm{\&pi;}}{2^{k+1}},$ Execution in step nine then,

Step 8, provide next rotor given position angle ${\mathrm{\&theta;}}_e(k+1)={\mathrm{\&theta;}}_e\left(k\right)+\frac{\mathrm{\&pi;}}{2^{k+1}},$ Execution in step nine then,

Step 9, judge whether to satisfy condition $\frac{\mathrm{\&pi;}}{2^{k+1}}<\mathrm{\&alpha;},$ Wherein, α is that precision allow to increase angle: and 0.5 °＜α＜1 °, judged result is for being, execution in step 11, judged result be for denying, execution in step ten,

The q shaft current i of step 10, the permanent-magnetic synchronous motor stator that resets _q=0, make k=k+1, execution in step two then;

Step 11, initial position angle of rotor be the value of declaring θ just _e(first)=θ _e(k),

Step 12, with rotor given position angle θ _e(k) be rotated counterclockwise 90 degree, produce a torque perpendicular to the rotor field direction,

Step 13, make i _Qref=i _{Q max}* p%, i _Dref=0, according to i _QrefAnd i _Dref, and adopt SVPWM Control Method control output stator electric current to set up stator field, drive rotor to rotor given position angle θ _e(k) direction rotation,

Wherein, p% gets the q shaft current amplitude limit value i of permanent-magnetic synchronous motor stator _{Q max}2%～5%,

Step 14, judge permagnetic synchronous motor 1 line that whether turns clockwise,

Judged result is not for, and execution in step 15, judged result be for being, execution in step 16,

Step 15, obtain initial position angle of rotor θ _e(initial)=θ _e(fisrt),

Step 10 six, obtain initial position angle of rotor θ _e(initial)=θ _e(fisrt)+π.

Indicate item: all angles of mentioning among the present invention are electrical degree.

Fig. 3 is the AC servo of permagnetic synchronous motor, the positional information that adopts incremental encoder 1 to gather permanent-magnetic synchronous motor rotor in this system, and promptly the A/B/Z signal is given AC servo driver 2, the stator current i of sampling permagnetic synchronous motor _a, i _b, the fixed relationship of three characteristics of the middle term electric current, the two-phase of only sampling can obtain i _cData, the stator current that sampling obtains also feeds back to AC servo driver 2, AC servo driver 2 sends corresponding order control permagnetic synchronous motor according to the information that feeds back.A position that very important parameter is a rotor when the control permagnetic synchronous motor.Introduce below and use incremental encoder 1 to realize the method that permanent-magnet synchronous motor rotor position detects:

Suppose that it provides pulse number in T preset time (s) in rotary course be a, then motor speed n (r/min) can be expressed as:

n＝60×(a/T)×N (1)

In the formula (1), N is the umber of pulse of incremental encoder 1 revolution output.

Suppose that motor initial position angle of rotor when static is θ _e(initial), the number of pole-pairs of motor is p, the rotor-position of the motor behind the static beginning elapsed time T (s) then, and the pass between the motor speed degree is:

θ _e(k)＝θ _e(initial)+p×(n×T/60)×2π

(2)

＝θ _e(initial)+2π×p×a/N

This θ _eCarry out the needed rotor position angle of coordinate transform when (k) angle is exactly vector control.Its transform vector equation is:

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\sqrt{\frac{2}{3}\left[\begin{array}{ccc}\cos {\mathrm{\&theta;}}_e\left(k\right)& \cos ({\mathrm{\&theta;}}_e\left(k\right)-\frac{2}{3}\mathrm{\&pi;})& \cos ({\mathrm{\&theta;}}_e\left(k\right)+\frac{2}{3}\mathrm{\&pi;})\\ \sin {\mathrm{\&theta;}}_e\left(k\right)& \sin ({\mathrm{\&theta;}}_e\left(k\right)-\frac{2}{3}\mathrm{\&pi;})& \sin ({\mathrm{\&theta;}}_e\left(k\right)+\frac{2}{3}\mathrm{\&pi;})\end{array}\right]}\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right]---\left(3\right)$

After i sampling time finished, promptly i sampled value was:

θ _e(i)＝θ _e(i-1)+2π×p×a _i/N (4)

In the formula (3), i is a positive integer, a _iIt is the counted number of pulses in i sampling period.

In formula (4) substitution formula (3), try to achieve this moment permagnetic synchronous motor electrical quantity after the respective value in the d-q axle system, system can be by suitable adjuster to specified amount (as q shaft current i _q) regulate, then at i _dUnder=0 situation, the Mathematical Modeling of permagnetic synchronous motor is:

$\left\{\begin{array}{c}{u}_q=R_s{i}_q+L_q\frac{{\mathrm{di}}_q}{\mathrm{dt}}+\mathrm{\&omega;}{L}_d{i}_d+{\mathrm{\&omega;}}_r{\mathrm{\&psi;}}_f\\ u_d=R_s{i}_d+L_q\frac{{\mathrm{di}}_d}{\mathrm{dt}}-{\mathrm{\&omega;}}_r{L}_q{i}_q\\ T_e=p{\mathrm{\&psi;}}_f{i}_q\\ T_e=J\frac{d({\mathrm{\&omega;}}_r/p)}{\mathrm{dt}}+R_{\mathrm{\&Omega;}}\frac{{\mathrm{\&omega;}}_r}{P_n}+T_1\end{array}\right.---\left(5\right)$

In the formula (5), ω _rBe permagnetic synchronous motor angular velocity of rotation, ψ _fBe permanent-magnetic synchronous motor rotor excitation magnetic linkage, R _ΩBe coefficient of friction, T _eBe permagnetic synchronous motor electromagnetic torque, T ₁Be permagnetic synchronous motor load torque, R _sBe permagnetic synchronous motor armature equivalent resistance.

At this moment, permagnetic synchronous motor mathematical model and direct current machine are identical, realize decoupling zero between d axle and the q axle, and system can imitate the control of DC method permagnetic synchronous motor is controlled.

As seen, permagnetic synchronous motor by coordinate transform, can convert the Equivalent DC motor to and control under rotor-position situation as can be known.As long as know original position of electric motor's rotator angle θ _e(initial), then the position of rotor any time all can be tried to achieve by formula (4), and the method that the present invention proposes is exactly the problem that solves the initial position that obtains permanent-magnetic synchronous motor rotor.

The inventive method adopts the common incremental encoder 1 of only exporting the A/B/Z signal, having remarkable advantages aspect cost, is that the incremental encoder cost of the exportable U/V/W signal condition that relates to of the Chinese patent of CN101409523 is much lower than publication number in the background technology.

Permanent magnet synchronous motor is the key link of AC synchronous governing system, and referring to shown in Figure 2, getting rotor permanent magnet first-harmonic excitation field axis is the d axle, and the q axle is along leading d axle 90 degree of direction of rotation, and the d-q axle is with angular velocity omega in company with rotor _rTogether rotation, its space coordinates is with d axle and the reference axis A angle θ of between centers mutually _eRepresent that (k) regulation A phase place axle---reference axis A axle mutually is a zero degree.Initial position angle of rotor θ then _e(initial) be the rotor field and the reference axis A angle between the axle mutually.

The electromagnetic torque of permagnetic synchronous motor depends on the component of stator current on the q axle basically.And the component main application on the d axle is an excitation, because the rotor flux of permagnetic synchronous motor is invariable, so generally adopt the vector control of pressing rotor flux linkage orientation, the essence of control is exactly to realize the torque control of AC permanent-magnet synchronous motor by the control to stator current.Rotating speed under the given situation of stator current, is controlled i when base speed is following _d=0 can more effective generation torque, and the inventive method mainly utilizes electromagnetic torque that rotor is rotated to the direction of setting, and therefore makes the q shaft current i of permanent-magnetic synchronous motor stator in step 1 _q=0, the d shaft current i of permanent-magnetic synchronous motor stator _d=0, in follow-up step, increase i _qValue, and i _dBe 0 always.

The control mode that the present invention takes is the i under synchronous rotating frame (d-q axle system) _d=0 closed-loop control guarantees d axle, q shaft current i _d, i _qCan tracing preset value---the given current i of d axle of stator _Dref, stator the given current i of q axle _QrefUnder synchronous rotating frame, Control of PMSM is not had the d-axis armature reaction, can not make the permanent magnet demagnetization, Current Control efficient height, electromagnetic torque can be utilized effectively.

Initialization rotor given position angle θ in the step 1 _e(k)=θ _e(0)=0, this moment k=0, the phase angle of promptly given stator field be 0 the degree.

Give the q shaft current i of permanent-magnetic synchronous motor stator in the step 2 _qIncrease Δ i _q, then the size of current of stator field and phase place are all given, execution in step three, the q shaft current i of judgement permanent-magnetic synchronous motor stator at this moment _qWhether greater than the q shaft current amplitude limit value i that sets _Qmax, judged result is not for, execution in step four, in the step 4 with the q shaft current i that obtains in the step 2 _qAssignment is given the given current i of q axle _Qref, with seasonal i _Dref=i _d=0, according to formula (3), with the given current i of q axle under the two synchronised rotary axis _QrefWith the given current i of d axle _DrefBe transformed into the threephase stator current i under the three phase static axle system _a, i _b, i _c, adopt SVPWM Control Method output threephase stator current i _a, i _b, i _cThe control permagnetic synchronous motor is set up stator field, and the method for definite initial position angle of rotor of permanent magnet synchronous motor that the present invention proposes is by control i _d, i _qControl stator three-phase current i indirectly _a, i _bAnd i _c, controlled quentity controlled variable is a DC quantity, rather than the sinusoidal quantity under the three-phase current control model, and the generation of control signal is complicated unlike producing sinusoidal signal, can control permagnetic synchronous motor as the control direct current machine, and control method is simple, and the control effect is obvious.

The current value of the stator field of this moment is i _Qref=i _q, i _Dref=i _d=0, phase place is θ _e(k), under the effect of stator field, rotor is driven to rotor given position angle θ _e(k) direction rotation, step 5 and step 6 are exactly to judge the rotation situation of rotor, if rotor did not both clockwise rotate, do not rotate counterclockwise yet, the magnetic direction that rotor is described may overlap with given stator field direction, in order to determine this conclusion, return execution in step two, continue to increase a current increase value Δ i _q, if 0 phase invariant is initial position angle of rotor θ _e(initial) be 0, then no matter how increase q shaft current i _qValue, rotor can not rotate, and sets a current limit i _{Q max}, work as i _q〉=i _{Q max}The time, determine conclusion: the output rotor initial position angle is the value of declaring θ just _e(first)=0;

If initial position angle of rotor θ _e(initial) be not 0, then it can rotate under given stator field effect, if clockwise rotate the m line, determines next rotor given position angle ${\mathrm{\&theta;}}_e(k+1)={\mathrm{\&theta;}}_e\left(k\right)+\frac{\mathrm{\&pi;}}{2^{k+1}},$ Promptly the phase place of next given stator field is Rotor turns clockwise, the angle that given stator field this moment is described is less than rotor field and A angle mutually spool, rotor wants dextrorotation to turn to stator field to draw close, to reach the purpose that two magnetic fields overlap, after determining this conclusion, program is adjusted the phase place of next stator field counterclockwise, and the rotor field is approached to given stator field phase place; If rotate counterclockwise the m line, determine next rotor given position angle ${\mathrm{\&theta;}}_e(k+1)={\mathrm{\&theta;}}_e\left(k\right)-\frac{\mathrm{\&pi;}}{2^{k+1}},$ Promptly the phase place of next given stator field is Rotor is rotated counterclockwise, the angle that given stator field this moment is described is greater than rotor field and A angle mutually spool, rotor will be rotated counterclockwise to stator field and draw close, to reach the purpose that two magnetic fields overlap, after determining this conclusion, program is adjusted the phase place of next stator field clockwise, and the rotor field is approached to given stator field phase place.The phase place of stator field is rotor given position angle just, and for control precision, general m selects 5 lines～10 lines.

After rotor process step 7 or the step 8, judge the angle of rotating when given stator field is approached in each rotor field Whether allow to increase angle [alpha] less than the precision of setting, 0.5 °＜α＜1 °, if $\frac{\mathrm{\&pi;}}{2^{k+1}}<\mathrm{\&alpha;},$ Illustrate that rotor field and given stator field are very approaching, in the scope of the precision that allows, regard as the rotor field and overlap, the phase theta at this moment given magnetic field with stator field _e(k) be place, the rotor field direction of being asked, constantly change the phase place of stator field in the above-mentioned steps, its purpose is exactly to allow given stator field constantly approach actual position, rotor field, promptly regard as given stator field and overlap in case satisfy the condition of step 9, obtain the step 11 initial position angle of rotor value of declaring θ just with the rotor field _e(first).

The inventive method is for initial position angle of rotor θ _e(initial) definite step is divided two stages: determine that rotor magnetic pole direction (being parallel to magnetic field) and definite rotor magnetic pole point to (direction of N, the S utmost point).Phase I as described in the step 11, is determined the set-point of electrical degree by judging encoder rotation direction and rotational line number (m line) as step 1, and the rotor field is approached in the magnetic field that stator current is produced gradually.When reaching given amplitude limit value of electric current or precision and reach requirement, finish the phase I, enter second stage, second stage only needs to judge the rotation direction of this rotor, do not need system log (SYSLOG) last time rotor turn to, so overhead descends, simplified software programming work.Simultaneously, given current limit i _{Q max}, code-disc rotational line number and precision allow to increase parameter such as angle [alpha] and can artificially be provided with, and can guarantee each judge accurately reliable, the uncertain influence of having avoided external interference to cause has increased control flexibility and degree of intelligence.In the second stage, judged the tangential direction of rotor magnetic pole, had two kinds of situations: the direction of having judged is pointed to coincidence or opposite with rotor magnetic pole.In order accurately to judge the sensing of magnetic pole, angle and the actual angle avoiding judging differ 180 degree, by on the angle value basis of having judged, increasing the mode of 90 degree, control stator current once more to produce electromagnetic torque perpendicular to the magnetic direction of judging in the first step, make rotor have the trend of rotating to the magnetic direction normal direction, by judging that rotor turns to, finally determine the actual rotor initial position angle.After finishing initial angle and determining work, withdraw from the initial alignment process.Second stage as described in the step 10 six, specifies as follows as step 12:

In the step 12, the phase place of given stator field is rotated counterclockwise 90 degree, be for produce one straight in the torque of rotor field direction, purpose is for by rotor clockwise or being rotated counterclockwise the magnetic pole of judging rotor arranges, just the real direction in rotor field.Stator current given in the step 13 is bigger than electric current given in the abovementioned steps, purpose be torque for the stator field that produces even as big as allowing rotor rotation, can not allow rotor that the error situation of not rotating takes place.

Step 14, and judges that if the step 14 condition is set up, rotor has turned clockwise, and the initial position angle of rotor value of declaring θ just is described as long as rotor rotation 1 line will be detected _e(first) Zhi Shi direction vector is consistent with the direction indication of rotor field reality, and then initial position angle of rotor is θ _e(initial)=θ _e(fisrt); If step 14 is false, then rotor has been rotated counterclockwise 1 line, and the initial position angle of rotor value of declaring θ just is described _e(first) Zhi Shi direction vector is just in time opposite with the direction indication of rotor field reality, differs 180 degree, and then initial position angle of rotor is θ _e(initial)=θ _e(fisrt)+π.

Embodiment two, below in conjunction with Fig. 1, Fig. 3 and Fig. 4 present embodiment is described, the difference of present embodiment and execution mode one is, judges in the step 5 that whether the turned clockwise method of m line of motor is:

Adopt incremental encoder to measure the positional information of permanent-magnetic synchronous motor rotor, when m pulse of described incremental encoder output, and the A pulse of exporting is when lagging behind B pulse 90 and spending, then the permagnetic synchronous motor m line that turned clockwise.

Judge in the step 6 that the method whether motor has been rotated counterclockwise the m line is:

Adopt incremental encoder to measure the positional information of permanent-magnetic synchronous motor rotor, when m pulse of described incremental encoder output, and the A pulse advance of exporting is when B pulse 90 is spent, and then permagnetic synchronous motor has been rotated counterclockwise the m line.

Other step is identical with execution mode one.

Fig. 4 provides a systematic schematic diagram of realizing the AC servo driver 2 of the method for the invention, the ac input signal of described AC servo driver 2 is through rectification circuit, soft starting circuit powers on, filter circuit and energy-dissipating brake circuit enter IPM three-phase inversion bridge circuit, the output signal of rectification circuit is also exported to digital signal processor as working power by the control power supply, the soft start control signal of digital signal processor output is exported to the soft starting circuit that powers on by control relay circuit, the pwm control signal of digital signal processor output converts 6 road PWM drive signals to by the switching tube Drive and Control Circuit and exports to the IPM three phase inverter bridge, the switching tube Drive and Control Circuit is also exported brake control signal and is given energy-dissipating brake circuit, electric current A/D sampling module will be gathered the two-way current signal that obtains and export to digital signal processor, and modulate circuit is exported to digital signal processor with the code device signal that collects.

Execution mode one described method for determining initial position angle of rotor of permanent magnet synchronous motor is compiled into the initial position of rotor trace routine, be arranged in the digital signal processor (DSP), be core with digital signal processor (DSP) in the AC servo driver 2, adopt incremental encoder 1 to measure the positional information of permanent-magnetic synchronous motor rotor, be the A/B/Z signal, described A/B/Z signal is exported to digital signal processor after handling through modulate circuit.

The feature of incremental encoder 1 is only to export A, B, Z three road pulse signals, wherein A, B signal are quadratures, when permagnetic synchronous motor just changes, the A impulse phase is ahead of B pulse 90 degree, when permagnetic synchronous motor reverses, the A impulse phase lags behind B pulse 90 degree, and permagnetic synchronous motor whenever turns around, Z pulse of incremental encoder 1 output.The QEP module of digital signal processor the inside participates in handling the signal that incremental encoder 1 feeds back, and can obtain turning to and the rotational pulse number of permagnetic synchronous motor.

Adopt execution mode one described method for determining initial position angle of rotor of permanent magnet synchronous motor to calculate initial position angle of rotor θ _e(initial), calculating initial position angle of rotor θ _e(initial) in the process, by the given current i of program setting q axle _Qref, the given electric i of d axle _Dref,, press the SVPWM mode by switching tube drive control circuit IPM three phase inverter bridge output threephase stator current i through coordinate transform _a, i _bAnd i _c, set up stator field, drive rotor to rotor given position angle θ _e(k) operating state of controlling the IPM three phase inverter bridge by SVPWM mode output drive signal is controlled in direction rotation based on field orientation.

Utilize electric current A/D sampling module to gather the two-phase stator current i of tested permagnetic synchronous motor _aAnd i _b, and export to digital signal processor, the fixed relationship of three characteristics of the middle term electric current, the two-phase of only sampling stator current i _aAnd i _bCan obtain i _cData, digital signal processor sends corresponding order according to the information that feeds back and rotates by IPM three phase inverter bridge output corresponding motor drive signal control permagnetic synchronous motor, this is current closed-loop control, the threephase stator current i that sampling obtains _a, i _bAnd i _cGiven electric current identical (after coordinate transform) with program setting.

Digital signal processor obtains the A/B/Z signal that stator current value and incremental encoder 1 feed back according to electric current A/D sampling module, adopt execution mode one described method for determining initial position angle of rotor of permanent magnet synchronous motor, calculating is also exported 6 road PWM ripple signals in the IPM three-phase inverter, control stator output current, and then the rotation of control stator field, drive motors rotates.

The formation of stator current is determined that by two kinds of parameters a kind of is stator current value of feedback i _a, i _bAnd i _c, a kind of is the absolute location information of rotor.And the incremental encoder 1 that only adopts the A/B/Z formula can not obtain the rotor absolute information, can only obtain relative increment information, so, adopt execution mode one described method to obtain initial position of rotor information, obtain increment information in conjunction with incremental encoder 1 again, obtain the absolute information of rotor.After finishing initial angle and determining work, withdraw from the initial alignment process.In case after initial position message obtained, the computational methods of output current were just as broad as long with general incremental encoder.

Claims (3)

1, method for determining initial position angle of rotor of permanent magnet synchronous motor is characterized in that, this method may further comprise the steps:

Step 1, the following variate-value of initialization:

The q shaft current i of permanent-magnetic synchronous motor stator _q=0, the d shaft current i of permanent-magnetic synchronous motor stator _d=0, make k=0, rotor given position angle θ _e(k)=θ _e(0)=0,

Step 2, with the q shaft current i of permanent-magnetic synchronous motor stator _qIncrease Δ i _q, i.e. i _q=i _q+ Δ i _q, Δ i _qBe q shaft current increment value, Δ i _qGet the q shaft current amplitude limit value i of permanent-magnetic synchronous motor stator _{Q max}1%～5%,

Step 3, judge whether the i that satisfies condition _q〉=i _{Q max},

Judged result is for being, execution in step 11, judged result be not for, execution in step four,

Step 4, make the given current i of q axle _Qref=i _q, the given electric i of d axle _Dref=i _d, with the given current i of q axle under the two synchronised rotary axis _QrefWith the given current i of d axle _DrefBe transformed into the threephase stator current i under the three phase static axle system _a, i _bAnd i _c, adopt SVPWM Control Method output threephase stator current i _a, i _bAnd i _cThe control permagnetic synchronous motor is set up stator field, drives rotor to rotor given position angle θ _e(k) direction rotation,

Step 5, judge the permagnetic synchronous motor m line that whether turned clockwise, wherein setting m is that permagnetic synchronous motor allows the rotational line number: m gets 5 lines～10 lines,

Judged result is for being, execution in step eight, judged result be not for, execution in step six,

Step 6, judge whether permagnetic synchronous motor has been rotated counterclockwise the m line,

Judged result is for being, execution in step seven, judged result be not for, permagnetic synchronous motor execution in step two,

Step 7, provide next rotor given position angle ${\mathrm{\&theta;}}_e(k+1)={\mathrm{\&theta;}}_e\left(k\right)-\frac{\mathrm{\&pi;}}{2^{k+1}},$ Execution in step nine then,

Step 8, provide next rotor given position angle ${\mathrm{\&theta;}}_e(k+1)={\mathrm{\&theta;}}_e\left(k\right)+\frac{\mathrm{\&pi;}}{2^{k+1}},$ Execution in step nine then,

Step 9, judge whether to satisfy condition $\frac{\mathrm{\&pi;}}{2^{k+1}}<\mathrm{\&alpha;},$ Wherein, α is that precision allow to increase angle: and 0.5 °＜α＜1 °, judged result is for being, execution in step 11, judged result be for denying, execution in step ten,

The q shaft current i of step 10, the permanent-magnetic synchronous motor stator that resets _q=0, make k=k+1, execution in step two then;

Step 11, initial position angle of rotor be the value of declaring θ just _e(dirst)=θ _e(k),

Step 12, with rotor given position angle θ _e(k) be rotated counterclockwise 90 degree, produce a torque perpendicular to the rotor field direction,

Step 13, make i _Qref=i _{Q max}* p%, i _Dref=0, according to i _QrefAnd i _Dref, and adopt SVPWM Control Method control output stator electric current to set up stator field, drive rotor to rotor given position angle θ _e(k) direction rotation,

Wherein, p% gets the q shaft current amplitude limit value i of permanent-magnetic synchronous motor stator _{Q max}2%～5%,

Step 14, judge permagnetic synchronous motor 1 line that whether turns clockwise,

Judged result is not for, and execution in step 15, judged result be for being, execution in step 16,

Step 15, obtain initial position angle of rotor θ _e(initial)=θ _e(fisrt),

Step 10 six, obtain initial position angle of rotor θ _e(initial)=θ _e(fisrt)+π.

2, method for determining initial position angle of rotor of permanent magnet synchronous motor according to claim 1 is characterized in that, judges in the step 5 that whether the turned clockwise method of m line of permagnetic synchronous motor is:

Adopt incremental encoder to measure the positional information of permanent-magnetic synchronous motor rotor, when m pulse of described incremental encoder output, and the A pulse of exporting is when lagging behind B pulse 90 and spending, then the permagnetic synchronous motor m line that turned clockwise.

3, method for determining initial position angle of rotor of permanent magnet synchronous motor according to claim 1 is characterized in that, judges in the step 6 that the method whether permagnetic synchronous motor has been rotated counterclockwise the m line is:

Adopt incremental encoder to measure the positional information of permanent-magnetic synchronous motor rotor, when m pulse of described incremental encoder output, and the A pulse advance of exporting is when B pulse 90 is spent, and then permagnetic synchronous motor has been rotated counterclockwise the m line.