Sensor-Less Speed Control Strategy for IM Drive Incorporating Vector Controlled Scheme PWM Inverter-Fed With Auto-Tuning Machine Parameter

8/14/2019 Sensor-Less Speed Control Strategy for IM Drive Incorporating Vector Controlled Scheme PWM Inverter-Fed With Au

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Sensor-less Speed Control Strategy for Induction Motor Drive Incorporating VectorControlled Scheme PWM Inverter-Fed with Auto-Tuning Machine ParameterEstimationKoji Soshin*, Tarek Ahmed, Prof. Mutsuo Nakaoka** Yukihiko Okam ura

Yamaguchi University2- 16-1 Tokiwa -daiUbe Ci ty , YAMAGUCHI 755-8611Matsush i ta E lectr ic W orks , L td1048 KadomaOsaka 571-8686

J A P A N J A P A N*[email protected], ** [email protected] [email protected] p

A b" I - This paper presents a feasible development on ahighly accurate quick response adjustable speed driveimplementation for general purpose induction motor whichoperates on the basis of sensorless slip frequency type vectorcontrolled sine-wave PWM inverter with automatic tuningmachine parameter estimation schemes.The dynamic speed response performances for largelychanged load torque disturbancesas well as steady sta te speed vs.torque characteristics of this induction motor controlimplementation are illustrated and discussed from anexperimental point of view.1. INTRODUCTION

In recent years, a variety of advanced power electronicscon tro l a nd systems in teg rat ion techn o log ies re la ting to thehig h performance adjustable-speed drives for induction motorapp l icat ions which are based on t h e v o l t ag eso u rce t y p ethree-phase cu rrent controlled PWM inverter using IGBTs andits associated vector control scheme have attracted specialinterest in the fields of the industrial, transportation and.consumer AC motor d r ives as well as electric vehicle ACmotor d r ives .

B u t a is difficult to achieve the sufficient speed regulationaccuracy in s teady s ta te as well as the speed settling time indynam ic s ta te which are requ ired for wide speed setting rangesand largely changed load to rque d is tu rbances .

In order to so lve these feas ib le p rob lems men t ioned above,the a u thors have developed a simple and practical automaticau to - tun ing method to measure and es t imate the s ta to r androtor circuit parameters of application specific inductionmotors addition to some different types of general purposeinduc tion motors used from diverse application viewpoints.11. S Y S T E M D E S C RIP TIO N A N D C O N T R O L S T R A T AG E

In order to perfo rm the ' speed sensor less vecto r con tro l o fthe induction motor, Z-axis model which carried outcoord inates conversion at the synchro nous rotation rectangularcoordinates system (d-q coordinates ) which rotates in th eangu lar f requency of secondary magnetic flux from the equalcircuit expressed with 3 phase AC will be treated in this paper.Fig. 1 shows an ad justah lespeed induct ion moto r d r ivesystem using slip frequency mode vector control based onthree-phase PW M inverter using the latest IGBTs.Equat ion (1 ) gives the general voltage equation of induction

motor descr ibed and fo rmulated on rectangular coordinates

(d-q frame coordinates), in which rotation angle frequencydeno ted as a.' + a L p -0Gw (M lLJp - (M / L , )w

G m r , + % ~ (M/L,)o ( M / L , ) P0 -Mr,lL, w, + P

I;]=[Mr,IL, 0 r J L , + p --w,Where,ill : Exiting c u m n t componentofdaxis

4 :Torque current componentof w i sL,, ;Stator winding inductancer, : Rotor equivalen t inductancer, : Stator winding resistancer2 ; Rotorequivalent resistancep ;Differential operator(= d/dr )

~ Rotar angular speed~ Slip angular frequency

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Equation (3) is the stat esp ace vector equation obtained byrewriting ( I ) .

Torque of the induction motor T-is expressed as ( 4 )T, =~pM(i , ; i , , - i l d , i Z q )

= PM( i iq@2, i l d @ 2 q ) / L Z (4 )Where

: &axis current component oft he rotorizq d-ax is current component of the rotor@2d : &axis of magnetic-flux interlinkag e of the rotorA , : q-axisof magnetic-flux interlinkageof the rotor

Rotator interlinkage magnetic flux 4d qual to MI an dA, = o as shown in (9 , t is possible to control torque T,linearlyjust like the DC motor.

gZd= Mi,, (constant). A, = o ( 5 )The torque of T , shown i n (4) is expressed as follows

T, = P M O ~l i q 1L, ( 6 )Then, reference value a, f slip angular frequency can be

formulated by (7).W , = r Z M & L2Q,, = r2 i lq = K m i , q (7)

Vector controlled PW M inverter supplies the specific voltageexpressed by (8) substituting Ad = Mi, (constant) andhq= 0 to ( I ) for the induction motor.

In a transient condition, tt.e slip angular frequency W, isformulated as (9).

W, = r 2 M l G 4 d . i l q u L l A 4 / L , @ 2 d ~ p i l , (9)111. NOVEL PRACTICAL APPROACH MACHINE

PARAMETERS ESTIMATIONA. Measurement poss ibil i ty of a machineparameter

In this section, the novel automatic a uto tuning scheme of theinduction motor parameters i:; explained.Fig. 1 depicts the developed dynam ic model of the senselessvector controlled PWM inverter system.In Fig.1 detecting the stator current by the current sensor,carries out vector control operation by the microprocessorbased on that stator current value, calcu lates the voltagereference value for obtaining instant torque component current&a nd a s a result the voltage reference value is given to a3

.IO-1

Fig.2. Relation between errorof induction motorparameters ;and speed change.

-0EEw.-I :

-361 -**, *, 0 6% *' 'U, -(4 a lor resistanceYJ , . , , . . , ,

Under these conditions, a, s calculated from i,, byrewriting (3) and the velocity of induction motor could becoincided wi th the reference value of the stat or frequencyadding W , to speed reference U , ' .

-I*, -a>61, 0 A, ib., 1 4(c)Sta,tor i n d u ct ma

Fig.3. Relations hip betweon errorof induction motorparameters and speed van ation.

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phase-voltage type PW M inverter.They areThe vector control operation needs four motor parameters.

L, : Stator winding inductanceI , : Leaksge inductance'I : Stator windingr2 : Rotator equivalent resistance

Fig. 2 represents the experimental result of the inductionmotor spe ed regulation under the conditions of low frequencyat 3Hz and high frequency at 6OHz in case of adapting someerrors to four motor parameters.A s a result of Fig.2-(a) ,Fig.2-@) and Fig.2-(c), statorwinding resistance rI, tator winding inductance L , and rotor

resistance r2 influence to the speed regulation of the inductionmotor. But, Fig. 2-(d) shows that the leakage inductance I,does not give much influence.

The ab ove resul t shows as fol lows.If the parameters o f stator winding resistance r,, statorwinding inductance L,and rotator equivalent resistance r, canhe estimated, it is possible to control the three phase inductionmotor with sufficient accuracy.N e x t , in order to jud ge the possibility of measuremen t of aninduction m otor circuit constants required for vector controlinverter system , the relation between the stator windingresistance r, ,rotator equivalent resistance r2 stator windinginductance L, ,d-axis current component of the stator i , , ,q-axis current component o f the stator i,, and rotor angularspeed 13,f the induction motor parameter are measured.

Fig. 3 represents the experimental results of the rotor currentrkgulation so as to adapt in accordance with some errors tothree induction motor types of system circuit parameters.Fig. x a ) and 3(c) show that the variations of the statorwinding resistance r, and stator inductance L, cause the

variation of stator current i an d i,, .Therefore, it is possibleto est imate its stator winding resistance 4 and stator windinginductance r, by measuring the stator current. But Fig. 3 (b )shows that the speed sensing operation should be necessary tom,easure the rotor speed of the motor 0, tself becausechanging rotor resistance 'I changes the rotor speed ur hutnot the statorcurrent ("and i,,parameters without speed sensor is discussed below.B. Estimation of Stator Resistance

I S

The novel automatic estimation scheme of these motor

The rotor winding resistance r, should be est imated whenthis motor does not rotate to avoid the influence of the statorinductance L, . Und erthis cond ition, the induction motor doesnot generate the output torque at all, then the torque currentcomponent 4 is equal to zero, thus the equationv,, = 54,'

described as the product of r, and ild*can he obtained by~ubs t i tu t ing , ,~ 0 to (8).Accordingly, adapting this initial value of vU' o the m otor,

measuring actual exciting current t d and adjust ing r, value inorder that h d will be equal to i,**. As are sul t, stator resistancer, can he estimated.Fig. 4 shows the method to estima te the stator resistancer, This measuring apparatus cons ists of the integrator.

C. Estimation of Stator InductanceAfter m easuring r , , he stator inductanceL, is measuredafter

rotating the induction motor at constant speed with no-load. Inthis case, the deviation of angular v elocity m5 and the torquecurrent componen t i,g are Zero

Fig.4. Schematic block diagram to estimate resistanczof induction motor stator.

Fig.5. Schematicblock diagram to detect inductanceof statorwinding

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Substituting i,, 0 t o (S), (10) are obtained..*

'Id = 'I "ldv1s = w . @

@ = L .;'.I lTh e initial value of i,,, is: j,; = @ / L , (11)In (1 1) if the stator inductance is A,!, larger more than the

preset value into the inverter, exciting current component il di s s m a l l e r a s Ai , , . Th e n ( , = $ / L , wil l beandeform in to(12)

i,; + A i , d = @ / ( L ,+ A L , ) (12)Equation (13) is obtained by subtracting ( I I ) from (1 2),

Ai,d = [I / ( L ,+ A L , ) I / 41.@ (13)The d-axis vol tage V,d is influenced by the error of d-axis

current i,,, from (1 0)-(a) an d the error of 1: is included in theequation of defined as (14).

A v ld = r , . A i , d [ I @ + A L , ) - l / L , ] . r , . @ (14)Stator winding resistance q has been measured and fixed,

the difference between the reference value and the detectedvalue of A i , , depends on the m ismatched error of the statorinductance. Therefore, by adjust ing the reference value il d tobe th e same as the de tec ted i d , he stator inductance L , willbe exactly set to the actua l value.Th e s tator inductance est imation system is demonstrated inFig. 5.

A V, , = r , . A i , d = [ I / ( L , + ~ , ) - l / L , ] ~ r , . @14)Stator winding resistance has been measured and f ixed,

the difference between the reference value and the detectedvalue of Aild depen ds on the mismatched error of the statorinductance. Therefore, by adjust ing the reference value i,,to b e t h e s a m e as the detected(, , the stator inductance L, willbe ex actly set to the actual value.Th e stator inductance est imation system is demonstrated i nFig. 5 .D. Esrimotion of Roror Resistonce

When the terminals of the induction motor driven by theinverter are opened, the terminal voltage v, will decreasesgradually a s shown in Fig. 6. Th is voltage v, is defined as theresidual voltage, and represented by (1 5 )

b t ,-4Fig.6. Relationship between residual voltage of theinduction motor and output voltage o f the comparator

IPM

equivalent resistance detection~

conparator "e III II IL I

Fig.7. Schematic circuit block diagram ofdetecting residual vol tag .

Slip Angula!,Frequency Constant Calculator

L-

...ild : d axis current reference including theK m Slip angular-h-equency gain

measured a stator inductance value

Fig.8. Black diagram of rotor equivalent resistance detector o finduction m o ta rotor.

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va =-JL,M.I,~~$O . s i n ( w , t + e , ) (15)The d ampin g performance of residual voltage is determinedb y th e d am p in g t im e co n s t an tr, and the moto r speed&,. and

its f r eq u en cy is equal to the moto r speed .The damping t ime constan t T o is constituted of the rotor

res is tance rl and the ro to r inductance L,. (ru L, / r 2 )Theref ore, the rotor resistance r2can be calculated from the

damping t ime constan t wh ich is determined by the moto rterminal voltage.

Fig. 6 i l lustrated the relationship between the residua l voltageand the outpu t voltage of its detecting circuit. Fig. 7 alsoind icates the schem at ic b lock d iag ram of t he p rocess ing ci rcu i tto detec t the residual voltage.The detect ing ci rcu i t o f res idual vokage made up o f acompacto r and a photo-coupler, is too simple.As sh o w n in Fig. 6 an d 7, novel estimation system will he

explain ed in the following.Consider ing the ampl itude of the residual voltage alone, thepeak voltage value of the residual voltage v, i s def ined asV, =I-&w,M. I,,I , an d then equat ion (17) can be ob tained .Where,M : Mutual inductance between 4 and L2v c Voltage value in real time t of the residual-voltageU , Rotation angular velocity of the indu ction motor

Actual rotator current value which f low s just b efore thepower supply terminalof the induction motor is opening.

7 : Damping time constant(ru L , / r 2 (16)e, : Phase angle

In Fig. 6 , when t l which is the time for the residhal-voltagev, to decline and become criteria comparison voltage v , , ~ ssubst i tu ted in ( I 7), (1 8) will be obtaine d.

Calcu lating the logarithm of both the sides- 4 1%= (% 1vo ) (19)

Substituting (1 6 ) T, = L , / rl , L, 3 L, a n d (1 )-(c) $ = L, . i,,in to (19) and so lv ing abou t r2 he n (20) will be obtained. Itwill be clear that the rotator equivalent resistance r, can beobserved f rom (20).

The block diagram for estimating rotor equivalent resistance

Fig. 9 shows the experimental results of measuring somer, is show n in Fig. 8.kinds of motors by this estimation system and .The moto rs constan ts are as fo l lows;*Rated vo l tages are 200 an d 4 0 0 v .*Horse powers are f rom l i4hp to 5hp .

Fig.9. Rotor resistance v alues estimated by digital signalprocessor incorporated into invcrter

1 I*-.IIY,". */"~.I-..U""nb

Fig.10. Block diagram ofcontrol systcm with a novelautcHurning machine parameter estimation scheme.

Molorshdcxpccd N.=%vmI M Y l orS hl ns pE E d #,.U"27la ) lndvr l ionMoloryi fh2UUVolt r~cRl ln i 1h)lnductmn Molorw~lh lOOVoliagc nting

Fig.11. Chara cteristics between motor speed and torqueestimated by novel machine parameter autm uning method

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MotorTypeAType B

v e c t o r c o n t r o l system are able to be measured in short time an dhigh a c c u r a c y , and the validity an d p rac t i c a l i t y of n o v e lm e a s u r e m e n t s y s t e m w e r e c la .r if ie d.

REFERENCES[ I ] Toshiaki Okuyama, N O ~ Nuiimoto, TakayukiMa~sui;VectorControl

Scheme of Induction Moto r without Speed and Voltage Sensors.,EEJTransaction on Industry Applic ations Vol. I07, ppl9 1-198, Feb. I987[2] K ouhci Ohnisi, Kunio Miyachi, Masnyuki Terashima :An Approach toInduction Motor Drive wit11 Controlled Volfage So-, IEEJTransaction on Power and Eno-gy,pp25-30, Nov.1984[3] Toshiaki O h y- N O ~ Nujimoto, Himshi Fujii :Simplified VectorControl System without Speed and Voltage Sensors-EffectsofSettingE m n in Control Parameters and their Compensation J, IEElTransaction on ndustryApplications, Vol.110.pp.477-486,May.l990.[4 ] Nmki Ymamurq Masahiko Iw; iSala, H i m e Sakurai :PGlessVectorContra1 with Estimating Functions of Motor Parameter, IEEJTransaction an Indus try Applic ations. V01.107, NoS. pp.37 5378,May. I99 1

(5 1 Geng Yang, TungHai Chin: Hyperstability of the Full OerderAdaptive Observer far Vector Controlle&lnduction Motor Drivewithout SpeedSenso?, IEEJ Transaction an Industry Applications,Vol. I 12. pp. 1047-1 55, Nov.1992[6] T.Kawamoto, Y . 0 k a m q Y.lslUda and H.Abe: Blushless lntemationalConference 1993 (SMIC93). pp.5 1-58, Marl993[7] Yukihiko Okamura, Koji S o s h , Himaki Yuasa High PerformanceAdjustabh-Speed Induction IMotor Drive System using %nsodessVector Controlbased PW M Inverter with Auto-TuningMachine-Operated Estimation Scheme, IEE Japan Trans. RM.,RM-94-62,pp.21-30,ldy.199.4[8] Yukihiko Okamura, b u j l Saushin, rkihiro Yuasa, yisuo SuzukiMutsuo Nakaoka, Eiji Hiraki,: High Performance Adjustable-SpeedInduction Motor Drive System using Sensorless Vector ControlledPW M Inverter with Auto-Tuning Machine-Opemted ParameferEstimation Schemes; Pmcwdings Powersystems World PowerElectmnics and Conference, Intelligent Motion System pp.204-223,Sept. 1995[9] Yukihiko Okamura, Ibuji soushin, Pkihim Yuasa, %suo SuzukiMutsuo Nakaoka, Eiji Hiraki : High Perfamlance Adjustable-SpeedInduction Motor Drive System using Sensorless Vector ConmLbawdPWM Inverter with Auto-Tuning Machine-Operated ParameterEstimation Schemes;Roc. Of :IEE- Kom lntemational ConferenceonPower E lectmnics pp.804-809, t3ct.1995

[ IO] Hideki Sugimoto, Li Ding, M,usatoshi Kay asu : A n IdentificationMethod of Primary and Secondw Resistance for Vector UmhulledInduction Motor System, IEE 1% Domestic ConferenceTransaction, p997,Aril 1998.

ri(Q) r@) LI (H I2.50 2.47 0.151.54 I I .9 7 I 0.11

VI . CONCLUSIONIn this paper, the slip a n g u l a r - f r e q u e n c y control system speed

s e n s o r l e s s v e c t o r c o n t r o l method of t h e i n d u c t i on motor andt h e proposed a u t o m a t i c parameter m e a s u r i n g method of ap rac t i c a l i n d u c t i o n motor c i rcu i t were ex p l a i n ed , th e t r ia lp r o d u c t i o n e x p e r i m e n t a n d t h e a p p l i c a t io n experimentperformed th e property e v a l u a t i o n , an d th e validity was madec l e a r f r o m an e x p e r i m e n t a l s t a n d p o i n t ., stator winding inductance4 an d rotor e q u i v a l e n t r e s i s t a n c e , required in the sensorlessStator w i n d i n g r e s i s t a n c e

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Sensor-Less Speed Control Strategy for IM Drive Incorporating Vector Controlled Scheme PWM Inverter-Fed With Auto-Tuning Machine Parameter