CN103780193A - Method for detecting initial position of rotor of power robot - Google Patents

Abstract

The invention discloses a method for detecting the initial position of a rotor of a power robot. The method comprises the steps of firstly exerting three high-frequency low-voltage pulses on a motor by controlling a driving circuit, utilizing an average current oblique differential method for calculating wire inductance values Lab, Lbc and Lac, comparing the inductance values Lab, Lbc and Lac to determine the section of the position angle of the rotor, controlling an inverter to exert a high-frequency low-voltage pulse again according to the section of the position angle of the rotor, selecting the three optimal detection values in the four current peak value detecting processes for rotational coordinate transformation, and finally determining the initial position angle of the rotor. The method for detecting the initial position of the rotor of a permanent magnet synchronous motor can detect the initial position of the rotor of the permanent magnet synchronous motor quite accurately, and achieve smooth starting of the motor, the implementation process is simple, any motor parameters are not required to be depended on, the measuring result is accurate, and the method has the high engineering practical value.

Description

A kind of Power Robot method for detecting initial position of rotor

Technical field

The present invention relates to a kind of Power Robot method for detecting initial position of rotor, by detecting respectively after A, B, C phase inductance, calculate initial position of rotor by rotating coordinate transformation.

Background technology

At present, in the robot system of various structures, owing to adopting, the scheme efficiency of permagnetic synchronous motor (PMSM) is higher, and therefore this scheme has consequence.Particularly, in Power Robot and small scale robot, PMSM is because these advantages have obtained more application.And can carry out accurately estimating to be the precondition that magneto alternator High Performance Control Strategies (vector control or Direct Torque) and position-sensor-free operation realize to initial position of rotor, also be to be related to whether smoothly starting of robot, and can realize the key issue of maximum torque starting; Therefore, it is one of the focus of engineering technological research and difficulties that initial position of rotor detects always, especially in Power Robot, because what robot carried out is operating as basic is operation with high pressure, the circuit detecting is abnormally dangerous, inaccurate if initial position of rotor detects, and can cause the repercussion of Power Robot to rotate, result is likely because misoperation destroys whole power circuit and robot, the serious high voltage short circuit that even can cause.

Guarantee that motor does not rotate and the method for detection rotor initial position, current achievement in research is di/dt detection method and two kinds of high-frequency signal injections: di/dt detection method need to inject the series of voltage pulse that amplitude is identical, direction is different in motor, the size of detection more corresponding electric current is carried out estimated rotor initial position, this method is feasible, if but expected that accurate initial position of rotor need to apply the potential pulse of multiple different directions, comparatively complicated to the control of inverter; And employing High Frequency Injection, its basic principle is in motor, to inject specific high-frequency voltage signal, then detect current signal corresponding in motor to determine the initial position of rotor, but the method algorithm is comparatively complicated, implement comparatively difficulty, and need the extra hardware circuits such as low pass filter, increased cost.

In engineering, the method for comparatively conventional initial position of rotor is to force positioning mode, and this method need to be before robot operation, make by force robot rotate, this in Power Robot, be very unreliable be also impracticable.In addition some initial position detection methods, all need to rely on robot and drive parameter, and the accuracy that makes to operate reduces a lot.Therefore propose one and do not rely on robot driving parameter, and realize simply, initial position detection method is very necessary accurately.

Summary of the invention

Goal of the invention: in order to overcome the deficiencies in the prior art, the invention provides a kind of Power Robot method for detecting initial position of rotor, enough detect very accurately a kind of permanent-magnetic synchronous motor rotor initial position, realize the smooth starting of motor; Implementation process is simple, does not need to rely on any parameter of electric machine, and measurement result is accurate.

Technical scheme: for achieving the above object, the technical solution used in the present invention is:

A kind of Power Robot method for detecting initial position of rotor, first applies three high frequency low voltage pulses by controlling three-phase inverter (drive circuit) to magneto, and utilizes the oblique poor method of average current to calculate L _ab, L _bcand L _ac, pass through L _ab, L _bcand L _acrelatively determine between rotor position angle location; Then according between rotor position angle location, apply a high frequency low voltage pulse by controlling three-phase inverter to magneto again, in four line inductance detection processes, select three times optimum detected values to be rotated coordinate transform, finally determine initial position angle of rotor; Specifically comprise the steps:

(1) control mode of employing three-phase inverter conducting between two, be that each moment motor has two to be conducted, non-conduction mutually unsettled, apply three high frequency low voltage pulses to magneto, in the time that corresponding two are conducted, calculate corresponding two alternate inductance suc as formula (a) by line inductance computing module:

$\left\{\begin{array}{c}{L}_{\mathrm{ab}}\left({\mathrm{\θ}}_r\right)=\frac{{2U}_d}{{\mathrm{di}}_{\mathrm{ab}}/\mathrm{dt}{|}_{\mathrm{on}}-{\mathrm{di}}_{\mathrm{ab}}/\mathrm{dt}{|}_{\mathrm{off}}}\\ L_{\mathrm{ac}}\left({\mathrm{\θ}}_r\right)=\frac{{2U}_d}{{\mathrm{di}}_{\mathrm{ac}}/\mathrm{dt}{|}_{\mathrm{on}}-{\mathrm{di}}_{\mathrm{ac}}/\mathrm{dt}{|}_{\mathrm{off}}}\\ L_{\mathrm{bc}}\left({\mathrm{\θ}}_r\right)=\frac{{2U}_d}{{\mathrm{di}}_{\mathrm{bc}}/\mathrm{dt}{|}_{\mathrm{on}}-{\mathrm{di}}_{\mathrm{bc}}/\mathrm{dt}{|}_{\mathrm{off}}}\end{array}\right.---\left(a\right)$

Wherein: U _dfor DC bus-bar voltage; L _ab, L _bcand L _acbe respectively AB phase line inductance, BC phase line inductance and AC phase line inductance; Di/dt| _onfor the rate of change of Current rise; Di/dt| _offfor the rate of change of electric current decline; θ _rfor initial position angle of rotor;

According to the saliency of magneto, detect current peak and present following Changing Pattern with the conversion of rotor position angle:

$\left\{\begin{array}{c}{L}_{\mathrm{bc}}\left({\mathrm{\&theta;}}_r\right)=L_o+{\mathrm{<figure-callout\; id="2"\; label="L\; g"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">L</figure-callout>}}_g\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">cos</figure-callout>}2{\mathrm{\&theta;}}_r\\ L_{\mathrm{ac}}\left({\mathrm{\&theta;}}_r\right)=L_o+{\mathrm{<figure-callout\; id="2"\; label="L\; g"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">L</figure-callout>}}_g\cos (2{\mathrm{\&theta;}}_r+\frac{2}{3}\mathrm{\&pi;})\\ L_{\mathrm{ab}}\left({\mathrm{\&theta;}}_r\right)=L_o+{\mathrm{<figure-callout\; id="2"\; label="L\; g"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">L</figure-callout>}}_g\cos (2{\mathrm{\&theta;}}_r-\frac{2}{3}\mathrm{\&pi;})\end{array}\right.$

Wherein: L _ofor the mean value of every phase winding self-induction, be the existing parameter of motor, the mean value of each phase winding self-induction equates; L _g2for the secondary harmonic amplitude of every phase winding self-induction, be the existing parameter of motor, the secondary harmonic amplitude of each phase winding self-induction equates;

The inductance value L calculating in conjunction with formula (a) _ab, L _bcand L _ac, according to following criterion, tentatively judge initial position angle of rotor θ _r:

If L _bc>=L _ab>L _ac, θ _rit between the lane place being positioned at, is 0 °～30 ° or 180 °～210 °;

If L _ab>=L _bc>L _ac, θ _rit between the lane place being positioned at, is 30 °～60 ° or 210 °～240 °;

If L _ab>L _ac>=L _bc, θ _rit between the lane place being positioned at, is 60 °～90 ° or 240 °～270 °;

If L _ac>=L _ab>L _bc, θ _rit between the lane place being positioned at, is 90 °～120 ° or 270 °～300 °;

If L _ac>L _bc>=L _ab, θ _rit between the lane place being positioned at, is 120 °～150 ° or 300 °～330 °;

If L _bc>L _ac>=L _ab, θ _rit between the lane place being positioned at, is 150 °～180 ° or 330 °～360 °;

(2) the initial position angle of rotor θ obtaining based on preliminary judgement _r, according to θ _rinterval difference, the magnetic direction same/opposite that can cause permanent magnet magnetic extreme direction and winding current to produce, thus make iron core more saturated/reduce saturated, magnetic permeability reduce/increase, line inductance value reduces/becomes greatly, thereby makes L in (a) formula _ab, L _bcand L _acdiminish/become and be large, increase the impact of magnetic or degaussing for fear of electric machine iron core, we are according to θ _rinterval again apply a high frequency low voltage pulse to magneto, carry out initial position angle of rotor θ _rfinal judgement, rule as follows:

If (2a) initial position angle of rotor θ _rinterval be 30 °～90 ° or 210 °～270 °, apply high frequency low voltage pulse to AB phase, C is mutually unsettled: when A phase winding is connected with forward dc busbar voltage, calculate now AB phase line inductance be according to formula (a) when B phase winding is connected with forward dc busbar voltage, calculate now AB phase line inductance according to formula (a) and be

Average

according to motor coordinate transform basic theories, the relation between rest frame A-B-C and alpha-beta coordinate system can be expressed as:

$\left[\begin{array}{c}{L}_{\mathrm{\&alpha;}}\\ L_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{L}_{\mathrm{bc}}\\ L_{\mathrm{ac}}\\ {\mathrm{\&Sigma;L}}_{\mathrm{ab}}\end{array}\right]=\left[\begin{array}{cc}{L}_o& \mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">cos</figure-callout>}{2\mathrm{\&theta;}}_r\\ L_o& \sin 2{\mathrm{\&theta;}}_r\end{array}\right]$

So, initial position angle of rotor θ _rcan be expressed as:

${\mathrm{\&theta;}}_r=\left\{\begin{array}{c}\frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}\\ \mathrm{or}\\ \frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}+\mathrm{\&pi;}\end{array}\right.$

Meanwhile, if

initial position angle of rotor θ _rinterval be 30 °～90 °; If

initial position angle of rotor θ _rinterval be 210 °～270 °;

If (2b) initial position angle of rotor θ _rinterval be 0 °～30 °, 330 °～360 ° or 150 °～210 °, apply high frequency low voltage pulse to BC phase, A is mutually unsettled: when B phase winding is connected with forward dc busbar voltage, calculate now BC phase line inductance be according to formula (a)

when C phase winding is connected with forward dc busbar voltage, calculate now BC phase line inductance according to formula (a) and be

Average

according to motor coordinate transform basic theories, the relation between rest frame A-B-C and alpha-beta coordinate system can be expressed as:

$\left[\begin{array}{c}{L}_{\mathrm{\&alpha;}}\\ L_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}\mathrm{\&Sigma;}{L}_{\mathrm{bc}}\\ L_{\mathrm{ac}}\\ L_{\mathrm{ab}}\end{array}\right]=\left[\begin{array}{cc}{L}_o& \mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">cos</figure-callout>}{2\mathrm{\&theta;}}_r\\ L_o& \sin 2{\mathrm{\&theta;}}_r\end{array}\right]$

So, initial position angle of rotor θ _rcan be expressed as:

${\mathrm{\&theta;}}_r=\left\{\begin{array}{c}\frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}\\ \mathrm{or}\\ \frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}+\mathrm{\&pi;}\end{array}\right.$

Meanwhile, if

initial position angle of rotor θ _rinterval be 150 °～210 °; If

initial position angle of rotor θ _rinterval be 0 °～30 ° or 330 °～360 °;

If (2c) initial position angle of rotor θ _rinterval be 90 °～150 ° or 270 °～330 °, apply high frequency low voltage pulse to AC phase, B is mutually unsettled: when A phase winding is connected with forward dc busbar voltage, calculate now AC phase line inductance be according to formula (a) when C phase winding is connected with forward dc busbar voltage, calculate now AC phase line inductance according to formula (a) and be

Average

according to motor coordinate transform basic theories, the relation between rest frame A-B-C and alpha-beta coordinate system can be expressed as:

$\left[\begin{array}{c}{L}_{\mathrm{\&alpha;}}\\ L_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\mathrm{\&Sigma;}\begin{array}{c}{L}_{\mathrm{bc}}\\ L_{\mathrm{ac}}\\ L_{\mathrm{ab}}\end{array}\right]=\left[\begin{array}{cc}{L}_o& \mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">cos</figure-callout>}{2\mathrm{\&theta;}}_r\\ L_o& \sin 2{\mathrm{\&theta;}}_r\end{array}\right]$

So, initial position angle of rotor θ _rcan be expressed as:

${\mathrm{\&theta;}}_r=\left\{\begin{array}{c}\frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}\\ \mathrm{or}\\ \frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}+\mathrm{\&pi;}\end{array}\right.$

Meanwhile, if initial position angle of rotor θ _rinterval be 90 °～150 °; If initial position angle of rotor θ _rinterval be 270 °～330 °;

Wherein, L _αand L _βfor being transformed into the inductance value under alpha-beta coordinate system.

Beneficial effect: Power Robot method for detecting initial position of rotor provided by the invention, can examine very accurately the method for detecting initial position of rotor of Power Robot drive motors, realize the smooth starting of robot; Implementation process is simple, does not need to rely on the parameter of any robot drive motors, and measurement result is accurate, has very strong engineering practical value.

Accompanying drawing explanation

Fig. 1 is implementing procedure figure of the present invention;

Fig. 2 arrives AB phase for applying high frequency low voltage pulse, when C is mutually unsettled, and the equivalent circuit diagram that A phase winding is connected with forward dc busbar voltage;

Fig. 3 arrives AB phase for applying high frequency low voltage pulse, when C is mutually unsettled, and the equivalent circuit diagram that B phase winding is connected with forward dc busbar voltage;

Fig. 4 is initial position angle of rotor while being 45 °, for applying high frequency low voltage pulse to AB phase, and when C is mutually unsettled, increasing magnetic chart when A phase winding is connected with forward dc busbar voltage;

Fig. 5 is initial position angle of rotor while being 45 °, for applying high frequency low voltage pulse to AB phase, and when C is mutually unsettled, increasing magnetic chart when B phase winding is connected with forward dc busbar voltage;

Fig. 6 is line inductance block plan.

Embodiment

Below in conjunction with accompanying drawing, the present invention is further described.

Be illustrated in figure 1 a kind of Power Robot method for detecting initial position of rotor, first apply three high frequency low voltage pulses by controlling three-phase inverter (drive circuit) to magneto, and utilize the oblique poor method of average current to calculate L _ab, L _bcand L _ac, pass through L _ab, L _bcand L _acrelatively determine between rotor position angle location; Then according between rotor position angle location, apply a high frequency low voltage pulse by controlling three-phase inverter to magneto again, in four line inductance detection processes, select three times optimum detected values to be rotated coordinate transform, finally determine initial position angle of rotor; Specifically comprise the steps:

(1) control mode of employing three-phase inverter conducting between two, be that each moment motor has two to be conducted, non-conduction mutually unsettled, apply three high frequency low voltage pulses to magneto, in the time that corresponding two are conducted, calculate corresponding two alternate inductance by line inductance computing module;

As shown in Figure 2, to apply high frequency low voltage pulse to AB phase (T ₁and T ₄conducting), C is mutually unsettled is example, calculates L _ab, order:

L _ab(θ _r)=L _aa+L _bb+M _ab+M _ba

Wherein, L _aafor A phase self-induction, L _bbfor B phase self-induction, M _abfor the mutual inductance of A phase and B phase, M _bafor the mutual inductance of B phase and A phase;

Work as T ₁and T ₄conducting, when other power tubes turn-off, when A phase winding is connected with forward dc busbar voltage, B phase winding is while being connected with negative sense DC bus-bar voltage, voltage equation can be expressed as:

$U_d={2U}_T+2R{i}_{\mathrm{ab}}+L_{\mathrm{ab}}\left({\mathrm{\&theta;}}_r\right)\frac{{\mathrm{di}}_{\mathrm{ab}}}{\mathrm{dt}}{|}_{\mathrm{on}}$

Work as T ₁and T ₄turn-off, electric current is by diode VD ₂and VD ₃afterflow, voltage equation can be expressed as:

$-U_d={2U}_T+2R{i}_{\mathrm{ab}}+L_{\mathrm{ab}}\left({\mathrm{\&theta;}}_r\right)\frac{{\mathrm{di}}_{\mathrm{ab}}}{\mathrm{dt}}{|}_{\mathrm{off}}$

Wherein, U _dfor DC bus-bar voltage, U _ttube voltage drop during for power device conducting; R is the resistance of every phase winding, di/dt| _onfor the rate of change of Current rise; Di/dt| _offfor the rate of change of electric current decline;

Because power tube is very short from opening to time interval of shutoff, although the instantaneous value of line current is not identical, their mean value is almost identical, therefore, can suppose the U in above-mentioned two voltage equations _tchange interval mean value with R pressure drop at power tube on off state and all equate respectively, can obtain so:

$L_{\mathrm{ab}}\left({\mathrm{\&theta;}}_r\right)=\frac{{2U}_d}{{\mathrm{di}}_{\mathrm{ab}}/\mathrm{dt}{|}_{\mathrm{on}}-{\mathrm{di}}_{\mathrm{ab}}/\mathrm{dt}{|}_{\mathrm{off}}}$

In like manner, can be in the hope of L _bcand L _ac, obtain formula (a):

$\left\{\begin{array}{c}{L}_{\mathrm{ab}}\left({\mathrm{\&theta;}}_r\right)=\frac{{2U}_d}{{\mathrm{di}}_{\mathrm{ab}}/\mathrm{dt}{|}_{\mathrm{on}}-{\mathrm{di}}_{\mathrm{ab}}/\mathrm{dt}{|}_{\mathrm{off}}}\\ L_{\mathrm{ac}}\left({\mathrm{\&theta;}}_r\right)=\frac{{2U}_d}{{\mathrm{di}}_{\mathrm{ac}}/\mathrm{dt}{|}_{\mathrm{on}}-{\mathrm{di}}_{\mathrm{ac}}/\mathrm{dt}{|}_{\mathrm{off}}}\\ L_{\mathrm{bc}}\left({\mathrm{\&theta;}}_r\right)=\frac{{2U}_d}{{\mathrm{di}}_{\mathrm{bc}}/\mathrm{dt}{|}_{\mathrm{on}}-{\mathrm{di}}_{\mathrm{bc}}/\mathrm{dt}{|}_{\mathrm{off}}}\end{array}\right.---\left(a\right)$

Wherein: L _ab, L _bcand L _acbe respectively AB phase line inductance, BC phase line inductance and AC phase line inductance; θ _rfor initial position angle of rotor;

According to the saliency of magneto, detect current peak and present following Changing Pattern with the conversion of rotor position angle:

$\left\{\begin{array}{c}{L}_{\mathrm{bc}}\left({\mathrm{\&theta;}}_r\right)=L_o+{\mathrm{<figure-callout\; id="2"\; label="L\; g"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">L</figure-callout>}}_g\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">cos</figure-callout>}2{\mathrm{\&theta;}}_r\\ L_{\mathrm{ac}}\left({\mathrm{\&theta;}}_r\right)=L_o+{\mathrm{<figure-callout\; id="2"\; label="L\; g"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">L</figure-callout>}}_g\cos (2{\mathrm{\&theta;}}_r+\frac{2}{3}\mathrm{\&pi;})\\ L_{\mathrm{ab}}\left({\mathrm{\&theta;}}_r\right)=L_o+{\mathrm{<figure-callout\; id="2"\; label="L\; g"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">L</figure-callout>}}_g\cos (2{\mathrm{\&theta;}}_r-\frac{2}{3}\mathrm{\&pi;})\end{array}\right.$

Wherein: L _ofor the mean value of every phase winding self-induction, be the existing parameter of motor, the mean value of each phase winding self-induction equates; L _g2for the secondary harmonic amplitude of every phase winding self-induction, be the existing parameter of motor, the secondary harmonic amplitude of each phase winding self-induction equates;

The inductance value L calculating in conjunction with formula (a) _ab, L _bcand L _ac, according to following criterion, tentatively judge initial position angle of rotor θ _r:

If L _bc>=L _ab>L _ac, θ _rit between the lane place being positioned at, is 0 °～30 ° or 180 °～210 °;

If L _ab>=L _bc>L _ac, θ _rit between the lane place being positioned at, is 30 °～60 ° or 210 °～240 °;

If L _ab>L _ac>=L _bc, θ _rit between the lane place being positioned at, is 60 °～90 ° or 240 °～270 °;

If L _ac>=L _ab>L _bc, θ _rit between the lane place being positioned at, is 90 °～120 ° or 270 °～300 °;

If L _ac>L _bc>=L _ab, θ _rit between the lane place being positioned at, is 120 °～150 ° or 300 °～330 °;

If L _bc>L _ac>=L _ab, θ _rit between the lane place being positioned at, is 150 °～180 ° or 330 °～360 °;

(2) the initial position angle of rotor θ obtaining based on preliminary judgement _r, according to θ _rinterval difference, the magnetic direction same/opposite that can cause permanent magnet magnetic extreme direction and winding current to produce, thus make iron core more saturated/reduce saturated, magnetic permeability reduce/increase, line inductance value reduces/becomes greatly, thereby makes L in (a) formula _ab, L _bcand L _acdiminish/become and be large, increase the impact of magnetic or degaussing for fear of electric machine iron core, we are according to θ _rinterval again apply a high frequency low voltage pulse to magneto, carry out initial position angle of rotor θ _rfinal judgement, rule as follows:

If (2a) initial position angle of rotor θ _rinterval be 30 °～90 ° or 210 °～270 °, apply high frequency low voltage pulse to AB phase, C is mutually unsettled: when A phase winding is connected (a, b are conducted) with forward dc busbar voltage, calculate now AB phase line inductance to be according to formula (a)

when B phase winding is connected (b, a are conducted) with forward dc busbar voltage, calculate now AB phase line inductance according to formula (a) to be

Because inductance is subject to increasing the impact of magnetic and degaussing, have influence on the detection of current peak, thereby can cause rotor position angle θ _rerror, the therefore error of avoiding in order to try one's best, improve precision, average

according to motor coordinate transform basic theories, the relation between rest frame A-B-C and alpha-beta coordinate system can be expressed as:

$\left[\begin{array}{c}{L}_{\mathrm{\&alpha;}}\\ L_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{L}_{\mathrm{bc}}\\ L_{\mathrm{ac}}\\ {\mathrm{\&Sigma;L}}_{\mathrm{ab}}\end{array}\right]=\left[\begin{array}{cc}{L}_o& \mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">cos</figure-callout>}{2\mathrm{\&theta;}}_r\\ {\mathrm{<figure-callout\; id="2"\; label="L\; o\; sin"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">L</figure-callout>}}_o& \sin 2{\mathrm{\&theta;}}_r\end{array}\right]$

So, initial position angle of rotor θ _rcan be expressed as:

${\mathrm{\&theta;}}_r=\left\{\begin{array}{c}\frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}\\ \mathrm{or}\\ \frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}+\mathrm{\&pi;}\end{array}\right.$

Meanwhile, if

initial position angle of rotor θ _rinterval be 30 °～90 °; If

initial position angle of rotor θ _rinterval be 210 °～270 °; Be analyzed as follows:

If θ _rinterval be 30 °～90 °, in the time that a, b are conducted, the resultant magnetic field direction that permanent magnet magnetic extreme direction produces with winding current is identical, produce increase magnetic effect, thereby make iron core more saturated, magnetic permeability reduce, inductance value reduces, thereby makes the L calculating _abdiminish; In the time that b, a are conducted, the resultant magnetic field opposite direction that permanent magnet magnetic extreme direction and winding current produce, produce demagnetizing effect, thereby it is saturated that iron core is moved back, and magnetic permeability increases, and inductance value increases, thereby makes the L calculating _abbecome large; Therefore

If θ _rinterval be 210 °～270 °, situation is contrary;

If (2b) initial position angle of rotor θ _rinterval be 0 °～30 °, 330 °～360 ° or 150 °～210 °, apply high frequency low voltage pulse to BC phase, A is mutually unsettled: when B phase winding is connected (b, c are conducted) with forward dc busbar voltage, calculate now BC phase line inductance to be according to formula (a)

when C phase winding is connected (c, b are conducted) with forward dc busbar voltage, calculate now BC phase line inductance according to formula (a) to be

Because inductance is subject to increasing the impact of magnetic and degaussing, have influence on the detection of current peak, thereby can cause rotor position angle θ _rerror, the therefore error of avoiding in order to try one's best, improve precision, average

according to motor coordinate transform basic theories, the relation between rest frame A-B-C and alpha-beta coordinate system can be expressed as:

$\left[\begin{array}{c}{L}_{\mathrm{\&alpha;}}\\ L_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}\mathrm{\&Sigma;}{L}_{\mathrm{bc}}\\ L_{\mathrm{ac}}\\ L_{\mathrm{ab}}\end{array}\right]=\left[\begin{array}{cc}{L}_o& \mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">cos</figure-callout>}{2\mathrm{\&theta;}}_r\\ {\mathrm{<figure-callout\; id="2"\; label="L\; o\; sin"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">L</figure-callout>}}_o& \sin 2{\mathrm{\&theta;}}_r\end{array}\right]$

So, initial position angle of rotor θ _rcan be expressed as:

${\mathrm{\&theta;}}_r=\left\{\begin{array}{c}\frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}\\ \mathrm{or}\\ \frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}+\mathrm{\&pi;}\end{array}\right.$

Meanwhile, if

initial position angle of rotor θ _rinterval be 150 °～210 °; If

initial position angle of rotor θ _rinterval be 0 °～30 ° or 330 °～360 °; Be analyzed as follows:

If θ _rinterval be 0 °～30 ° or 330 °～360 °, in the time that b, c are conducted, the resultant magnetic field opposite direction that permanent magnet magnetic extreme direction and winding current produce, produce demagnetizing effect, thereby it is saturated that iron core is moved back, magnetic permeability increases, inductance value increases, thereby makes the L calculating _bcbecome large; In the time that c, b are conducted, the resultant magnetic field direction that permanent magnet magnetic extreme direction produces with winding current is identical, produces and increases magnetic effect, thereby make iron core more saturated, and magnetic permeability reduces, and inductance value reduces, thereby makes the L calculating _bcdiminish; Therefore

If θ _rinterval be 150 °～210 °, situation is contrary;

If (2c) initial position angle of rotor θ _rinterval be 90 °～150 ° or 270 °～330 °, apply high frequency low voltage pulse to AC phase, B is mutually unsettled: when A phase winding is connected (a, c are conducted) with forward dc busbar voltage, calculate now AC phase line inductance to be according to formula (a)

when C phase winding is connected (c, a are conducted) with forward dc busbar voltage, calculate now AC phase line inductance according to formula (a) to be

Because inductance is subject to increasing the impact of magnetic and degaussing, have influence on the detection of current peak, thereby can cause rotor position angle θ _rerror, the therefore error of avoiding in order to try one's best, improve precision, average

according to motor coordinate transform basic theories, the relation between rest frame A-B-C and alpha-beta coordinate system can be expressed as:

$\left[\begin{array}{c}{L}_{\mathrm{\&alpha;}}\\ L_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\mathrm{\&Sigma;}\begin{array}{c}{L}_{\mathrm{bc}}\\ L_{\mathrm{ac}}\\ L_{\mathrm{ab}}\end{array}\right]=\left[\begin{array}{cc}{L}_o& \mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">cos</figure-callout>}{2\mathrm{\&theta;}}_r\\ {\mathrm{<figure-callout\; id="2"\; label="L\; o\; sin"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">L</figure-callout>}}_o& \sin 2{\mathrm{\&theta;}}_r\end{array}\right]$

So, initial position angle of rotor θ _rcan be expressed as:

${\mathrm{\&theta;}}_r=\left\{\begin{array}{c}\frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}\\ \mathrm{or}\\ \frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}+\mathrm{\&pi;}\end{array}\right.$

Meanwhile, if

initial position angle of rotor θ _rinterval be 90 °～150 °; If

initial position angle of rotor θ _rinterval be 270 °～330 °; Be analyzed as follows:

If θ _rinterval be 90 °～150 °, in the time that a, c are conducted, the resultant magnetic field direction that permanent magnet magnetic extreme direction produces with winding current is identical, produce increase magnetic effect, thereby make iron core more saturated, magnetic permeability reduce, inductance value reduces, thereby makes the L calculating _acdiminish; In the time that c, a are conducted, the resultant magnetic field opposite direction that permanent magnet magnetic extreme direction and winding current produce, produce demagnetizing effect, thereby it is saturated that iron core is moved back, and magnetic permeability increases, and inductance value increases, thereby makes the L calculating _acbecome large; Therefore

If θ _rinterval be 270 °～330 °, situation is contrary;

Wherein, L _αand L _βfor being transformed into the inductance value under alpha-beta coordinate system.

Be briefly described below in conjunction with an example.

A method for detecting initial position of rotor for Power Robot, specifically comprises the steps:

(1) apply three high frequency low voltage pulses by controlling three-phase inverter to motor, and utilize the oblique poor method of average current, calculate line inductance value L _ab, L _bcand L _ac, by relatively determining between rotor-position location of three, according to Fig. 6, by comparing L _ab, L _bcand L _actentatively judge θ _rlane place between, suppose θ _r=45 °, i.e. L _ab>L _bc>L _acbe positioned at interval 2.

Because θ _rwhile between the lane place being positioned at being 30 °～90 °, making alive pulse is conducted b, a, T ₃, T ₄conducting, calculates line inductance compare simultaneously

with

for the error of avoiding of trying one's best, in order to improve line inductance identification precision, average here according to motor coordinate transform basic theories, the relation between rest frame A-B-C and alpha-beta coordinate system can be expressed as

$\left[\begin{array}{c}{L}_{\mathrm{\&alpha;}}\\ L_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{L}_{\mathrm{bc}}\\ L_{\mathrm{ac}}\\ {\mathrm{\&Sigma;L}}_{\mathrm{ab}}\end{array}\right]=\left[\begin{array}{cc}{L}_o& \mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">cos</figure-callout>}{2\mathrm{\&theta;}}_r\\ {\mathrm{<figure-callout\; id="2"\; label="L\; o\; sin"\; filenames="HDA0000469277370000041.png"\; state="\{\{state\}\}">L</figure-callout>}}_o& \sin 2{\mathrm{\&theta;}}_r\end{array}\right]$

So, rotor position angle θ _rcan be expressed as

${\mathrm{\&theta;}}_r=\left\{\begin{array}{c}\frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}\\ \mathrm{or}\\ \frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}+\mathrm{\&pi;}\end{array}\right.$

Now try to achieve θ _r=45 ° or 225 °, compare simultaneously

with

can obtain

θ _rbe positioned at 30 °～90 °, i.e. θ _r=45 °.

The above is only the preferred embodiment of the present invention; be noted that for those skilled in the art; under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (1)

1. a Power Robot method for detecting initial position of rotor, is characterized in that: first apply three high frequency low voltage pulses by controlling three-phase inverter to magneto, and utilize the oblique poor method of average current to calculate L _ab, L _bcand L _ac, pass through L _ab, L _bcand L _acrelatively determine between rotor position angle location; Then according between rotor position angle location, apply a high frequency low voltage pulse by controlling three-phase inverter to magneto again, in four line inductance detection processes, select three times optimum detected values to be rotated coordinate transform, finally determine initial position angle of rotor; Specifically comprise the steps:

(1) control mode of employing three-phase inverter conducting between two, be that each moment motor has two to be conducted, non-conduction mutually unsettled, apply three high frequency low voltage pulses to magneto, in the time that corresponding two are conducted, calculate corresponding two alternate inductance suc as formula (a) by line inductance computing module:

$\left\{\begin{array}{c}{L}_{\mathrm{ab}}\left({\mathrm{\&theta;}}_r\right)=\frac{{2U}_d}{{\mathrm{di}}_{\mathrm{ab}}/\mathrm{dt}{|}_{\mathrm{on}}-{\mathrm{di}}_{\mathrm{ab}}/\mathrm{dt}{|}_{\mathrm{off}}}\\ L_{\mathrm{ac}}\left({\mathrm{\&theta;}}_r\right)=\frac{{2U}_d}{{\mathrm{di}}_{\mathrm{ac}}/\mathrm{dt}{|}_{\mathrm{on}}-{\mathrm{di}}_{\mathrm{ac}}/\mathrm{dt}{|}_{\mathrm{off}}}\\ L_{\mathrm{bc}}\left({\mathrm{\&theta;}}_r\right)=\frac{{2U}_d}{{\mathrm{di}}_{\mathrm{bc}}/\mathrm{dt}{|}_{\mathrm{on}}-{\mathrm{di}}_{\mathrm{bc}}/\mathrm{dt}{|}_{\mathrm{off}}}\end{array}\right.---\left(a\right)$

Wherein: U _dfor DC bus-bar voltage; L _ab, L _bcand L _acbe respectively AB phase line inductance, BC phase line inductance and AC phase line inductance; Di/dt| _onfor the rate of change of Current rise; Di/dt| _offfor the rate of change of electric current decline; θ _rfor initial position angle of rotor;

According to the saliency of magneto, detect current peak and present following Changing Pattern with the conversion of rotor position angle:

$\left\{\begin{array}{c}{L}_{\mathrm{bc}}\left({\mathrm{\&theta;}}_r\right)=L_o+L_{g2}\cos 2{\mathrm{\&theta;}}_r\\ L_{\mathrm{ac}}\left({\mathrm{\&theta;}}_r\right)=L_o+L_{g2}\cos (2{\mathrm{\&theta;}}_r+\frac{2}{3}\mathrm{\&pi;})\\ L_{\mathrm{ab}}\left({\mathrm{\&theta;}}_r\right)=L_o+L_{g2}\cos (2{\mathrm{\&theta;}}_r-\frac{2}{3}\mathrm{\&pi;})\end{array}\right.$

Wherein: L _ofor the mean value of every phase winding self-induction, be the existing parameter of motor, the mean value of each phase winding self-induction equates; L _g2for the secondary harmonic amplitude of every phase winding self-induction, be the existing parameter of motor, the secondary harmonic amplitude of each phase winding self-induction equates;

The inductance value L calculating in conjunction with formula (a) _ab, L _bcand L _ac, according to following criterion, tentatively judge initial position angle of rotor θ _r:

If L _bc>=L _ab>L _ac, θ _rit between the lane place being positioned at, is 0 °～30 ° or 180 °～210 °;

If L _ab>=L _bc>L _ac, θ _rit between the lane place being positioned at, is 30 °～60 ° or 210 °～240 °;

If L _ab>L _ac>=L _bc, θ _rit between the lane place being positioned at, is 60 °～90 ° or 240 °～270 °;

If L _ac>=L _ab>L _bc, θ _rit between the lane place being positioned at, is 90 °～120 ° or 270 °～300 °;

If L _ac>L _bc>=L _ab, θ _rit between the lane place being positioned at, is 120 °～150 ° or 300 °～330 °;

If L _bc>L _ac>=L _ab, θ _rit between the lane place being positioned at, is 150 °～180 ° or 330 °～360 °;

(2) the initial position angle of rotor θ obtaining based on preliminary judgement _r, according to θ _rinterval difference, the magnetic direction same/opposite that can cause permanent magnet magnetic extreme direction and winding current to produce, thus make iron core more saturated/reduce saturated, magnetic permeability reduce/increase, line inductance value reduces/becomes greatly, thereby makes L in (a) formula _ab, L _bcand L _acdiminish/become and be large, according to θ _rinterval again apply a high frequency low voltage pulse to magneto, carry out initial position angle of rotor θ _rfinal judgement, rule as follows:

If (2a) initial position angle of rotor θ _rinterval be 30 °～90 ° or 210 °～270 °, apply high frequency low voltage pulse to AB phase, C is mutually unsettled: when A phase winding is connected with forward dc busbar voltage, calculate now AB phase line inductance be according to formula (a)

when B phase winding is connected with forward dc busbar voltage, calculate now AB phase line inductance according to formula (a) and be

Average

according to motor coordinate transform basic theories, the relation between rest frame A-B-C and alpha-beta coordinate system can be expressed as:

$\left[\begin{array}{c}{L}_{\mathrm{\&alpha;}}\\ L_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{L}_{\mathrm{bc}}\\ L_{\mathrm{ac}}\\ {\mathrm{\&Sigma;L}}_{\mathrm{ab}}\end{array}\right]=\left[\begin{array}{cc}{L}_o& \cos {2\mathrm{\&theta;}}_r\\ L_o& \sin 2{\mathrm{\&theta;}}_r\end{array}\right]$

So, initial position angle of rotor θ _rcan be expressed as:

${\mathrm{\&theta;}}_r=\left\{\begin{array}{c}\frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}\\ \mathrm{or}\\ \frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}+\mathrm{\&pi;}\end{array}\right.$

Meanwhile, if

initial position angle of rotor θ _rinterval be 30 °～90 °; If

initial position angle of rotor θ _rinterval be 210 °～270 °;

If (2b) initial position angle of rotor θ _rinterval be 0 °～30 °, 330 °～360 ° or 150 °～210 °, apply high frequency low voltage pulse to BC phase, A is mutually unsettled: when B phase winding is connected with forward dc busbar voltage, calculate now BC phase line inductance be according to formula (a)

when C phase winding is connected with forward dc busbar voltage, calculate now BC phase line inductance according to formula (a) and be

Average

according to motor coordinate transform basic theories, the relation between rest frame A-B-C and alpha-beta coordinate system can be expressed as:

$\left[\begin{array}{c}{L}_{\mathrm{\&alpha;}}\\ L_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}\mathrm{\&Sigma;}{L}_{\mathrm{bc}}\\ L_{\mathrm{ac}}\\ L_{\mathrm{ab}}\end{array}\right]=\left[\begin{array}{cc}{L}_o& \cos {2\mathrm{\&theta;}}_r\\ L_o& \sin 2{\mathrm{\&theta;}}_r\end{array}\right]$

So, initial position angle of rotor θ _rcan be expressed as:

${\mathrm{\&theta;}}_r=\left\{\begin{array}{c}\frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}\\ \mathrm{or}\\ \frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}+\mathrm{\&pi;}\end{array}\right.$

Meanwhile, if initial position angle of rotor θ _rinterval be 150 °～210 °; If

initial position angle of rotor θ _rinterval be 0 °～30 ° or 330 °～360 °;

If (2c) initial position angle of rotor θ _rinterval be 90 °～150 ° or 270 °～330 °, apply high frequency low voltage pulse to AC phase, B is mutually unsettled: when A phase winding is connected with forward dc busbar voltage, calculate now AC phase line inductance be according to formula (a)

when C phase winding is connected with forward dc busbar voltage, calculate now AC phase line inductance according to formula (a) and be

Average

according to motor coordinate transform basic theories, the relation between rest frame A-B-C and alpha-beta coordinate system can be expressed as:

$\left[\begin{array}{c}{L}_{\mathrm{\&alpha;}}\\ L_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\mathrm{\&Sigma;},\begin{array}{c}{L}_{\mathrm{bc}}\\ L_{\mathrm{ac}}\\ L_{\mathrm{ab}}\end{array}\right]=\left[\begin{array}{cc}{L}_o& \cos {2\mathrm{\&theta;}}_r\\ L_o& \sin 2{\mathrm{\&theta;}}_r\end{array}\right]$

So, initial position angle of rotor θ _rcan be expressed as:

${\mathrm{\&theta;}}_r=\left\{\begin{array}{c}\frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}\\ \mathrm{or}\\ \frac{1}{2}\arctan \frac{L_{\mathrm{\&beta;}}}{L_{\mathrm{\&alpha;}}}+\mathrm{\&pi;}\end{array}\right.$

Meanwhile, if

initial position angle of rotor θ _rinterval be 90 °～150 °; If

initial position angle of rotor θ _rinterval be 270 °～330 °;

Wherein, L _αand L _βfor being transformed into the inductance value under alpha-beta coordinate system.

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