SOME ASPECTS OF THE MAGNETIC FIELD DISTRIBUTION PROBLEMS OF LINEAR INDUCTION MOTOR

Transcription

1 International Journal on Technical and Physical Probles of Engineering (IJTPE) Published by International Organization of IOTPE ISSN IJTPE Journal June 2014 Issue 19 Volue 6 Nuber 2 Pages SOME ASPECTS OF THE MAGNETIC FIELD DISTRIBUTION PROBLEMS OF LINEAR INDUCTION MOTOR A. Meedov 1 T. Abbasov 1 M. Seker 2 1. Electrical Engineering Departent, Faculty of Engineering, Inonu University, Malatya, Turkey arif.eedov@inonu.edu.tr, teyuraz.abbasov@inonu.edu.tr 2. Divrigi Nuri Deirag Vocationally High School, Cuhuriyet University, Sivas, Turkey ustafaseker@cuhuriyet.edu.tr Abstract- In this study, linear otors has been exained with three-phase oving agnetic field odels and insufficiently-research parts of the proble have been interpreted as different odels in the literature has been evaluated. Polar step-change on the oving area has been odeled with variation of agnetic flux. The rotor and stator agnetic flux change has been deonstrated graphically and envelops during in different ties calculated theoretically. When these changes are taken into consideration, possible changes of graph in the oving agnetic field consist of three-phase has been plotted. Possible change odel in parts of rotor and stator of agnetic field are interpreted. In fact, taking into consideration the agnetic field, change of oving agnetic field on graph discussed the necessity of the disclosure in ters of the electroagnetic field theory or ponders otive force assuptions. Keywords: Linear Motor, Moving Magnetic Field, Magnetic Flux, Electroagnetic Force. I. INTRODUCTION Nowadays, due to the acceleration of technological and scientific advances, scientist required to design and use advanced technological application in technology and electro echanis. One of the ost iportant eleents of the technological processes used in the industry is electrical otors and drivers. With the progress of technology developents in power electronics and icroprocessor technology allows that ore efficient operation of electrical achines and drivers and the creation of ore flexible control systes. Therefore, today, the electrical achines drivers, is one of the coponents which base on robotic technology and flexible control systes. About 40 percent of electric otors used in industry are used achines and echaniss which forward-backward linear otion. Therefore, additional echaniss are needed for converting linear otion to rotary otion of the otor shaft. These additional echaniss are causes an increase in losses and decrease the flexibility of the achine s operating. Linear electric otors that have the ability to ove forward-backward allow the reoval of transission eleents such as repulsive, converter. This is provide that echaniss which working with linear electric otor connect to sae body. Thereby, a linear otor contributes to eliination of additional losses and flexible operation of the syste. In soe of the working echanis is not possible deterine the boundaries between linear electric otor drivers syste with working echaniss of autoatic control syste. In other words, linear otors constitute part and parcels with operating echaniss. Today, vast ajority of hundreds of scientific studies which published in the field of linear induction otors survey are take into account the effect of edge and tip theoretical research [1-9]. One of the probles encountered in the study of linear induction otors investigate the oving linear agnetic field [6, 7]. The agnetic field of an linear otors ore coplex than that of a rotating induction otor. At analysis of linear otor liited diensions of the inductor should be considered. Therefore it is necessary to investigate the agnetic fields beyond the inductor boundaries (edge effect and end effect), and interdependencies of these fields. Because of the phenoenon of end effect, additional factors ust be considered: there is a reduction of attraction force, and despite a balanced supply voltage, increased phase ipedance and phase differences of leading currents [8]. There are any ethods of analysis and syntesys of the agnetic field and end effects. Fro these approches three ethods are significiant which give reliable results of calculations for linear ethods, i.e. Shturan s [3], the Yaaura s ethod [10] and a ethod which utilizes the coefficient of longitudinal end effects [7]. An aproach which are sperated of agnetic field of linear induction otors and proposed by Sadovsky [9] has been shown in Figure 1. This approach has been used by any investigators [9]. 54

2 International Journal on Technical and Physical Probles of Engineering (IJTPE), Iss. 19, Vol. 6, No. 2, Jun Figure 1. Propogation curves of agnetic flux density in the air-gap of linear induction otor (Sadovski odel [9]) Although there is a large nuber of oving agnetic field odels presented in the literature, there are not different approaches and interpretations belonging to the foration and effect of such areas. The concept of linear electric otors is ore than 170 years old. The first proposal was patentetin The first linear induction otor (LIM) was patendent in 1890 [7]. The physical eaning of the aplitude of agnetic induction pulsation in inductor bank range has been announced for the first tie scientific study of Shturan G.I. [3]. This study deonstrated that getting the area two pulsations, another walking wave with constant aplitude in air gap. When one of these areas variables the hyperbolic cosine law, other varies with hyperbolic sine law. Slituran s odel which has been created to assess agnetic shunting event is assued that there are hypothetical areas of uncertain length in agnetic field between ends of agnetic circuit. In reference [4], the installed state of open agnetic circuit induction otor is exained. Here, using the ethod of superposition, prier and secondary areas has been exained separately. As a result of theoretical analysis, it is different losses of secondary circuit, speeds that ideal no-load operation, induction of oving agnetic field. This analysis are exained that secondary speed is different than synchronic speed, length of shunt ranges and other probles [2]. Other sources are taking into the spread of wavefor area. Siulation of flux density under different tooth s obvious that agnetic field under ending and iddle tooth pulsates with different aplitudes and phases [8]. By investigating agnetic flux outside the inductor at different air gap widths, it is shown that characteristic are not linear: then is big air gap width, when dependency on air gap width changing is lower. Magnetic flux density in the air gap varies ore in cross-section near inductor and in cross-section near secondary eleent. The exaining theoretical and experiental results presented in literature of oving agnetic field are shown that different odels in this topic are described under different condition. Moreover, none of the odels is not X X copletely explain the foration of walking agnetic area and effect of echaniss. For this reason, lack of these probles in walking agnetic fields, both theory and practical application, exained and ore detail investigations are needed. II. MODELING OF MOVING MAGNETIC FIELD As is known, the running of the otor and other theoretical exaining are perfored in rotating electric otors, however, take into consideration the rotating agnetic field. Electrical field which occurring in this situation is not considered because of it is very sall. In analysis and design of linear electrical otors are used electroagnetic wave theories. Therefore, in the literature there are no knowledge about two pulsations field which is reported in [3], secondary speed which is different fro synchronous speed in [4] and the length and foration of shunt ranges. In this study, the effect of this fields has been neglected in linear otors because of the effect of electrical field to operating otor is less than and considering the effect of agnetic field, oving agnetic field are exained. The laboratory odel of the linear induction otor has been ade and exained for coparing the theoretical and experiental investigation and consolidation of result which are obtained (Figure 2). Figure 2. Views of linear induction otor: side view; top wiev Part of the odel which is used to perfor the experients is presented in Figure 3.Width and length of agnetic circuit is respectively 0.01 and 1. Magnetic circuit has been constituted ш-shaped sheets which has been prepared electrical steel with thickness of 0,35. 55

3 International Journal on Technical and Physical Probles of Engineering (IJTPE), Iss. 19, Vol. 6, No. 2, Jun Placeent of bobbin and agnetic flux lines which generated A-phase represented in Figure 3. Bobbins of each phase are connected to as back to each other. Magnetic flux lines which generated by A-phase represented in Figure 4. Here, ajor flux line fro the parts of the agnetic circuit placed A-phase bobbin, φ ϭ agnetic flux fro the agnetic circuit of B and C are covered infinite discontinuity. In the sub-grade, according to flux lines are covered with ferroagnetic aterial, leakage areas ay not be taking into consideration. Figure 3. Placeent of bobbins in linear induction otor Ф a -agnetic flux fored by A phase bobbin and lines of fugitive agnetic flux-ф бk In this procedure, values that are calculated at different tie of are presented in Table 1. T Table 1. Values that are calculated at different tie of φ T ωt Φ ωt Φ ( ). Φ ( ). Φ =0 =1.732 Φ 30 ( ) Φ =2Φ 330 ( ) Φ =Φ ( ) Φ 60 ( ) Φ 360 =1.732Φ =1.732Φ 90 ( ) Φ =Φ 390 ( ) Φ =2Φ 120 ( ) Φ =0 420 ( ) Φ =1.732Φ 150 ( ) Φ =-Φ 450 ( ) Φ =Φ 180 ( ) Φ =-1.732φ 480 ( ) Φ =0 210 ( ) Φ =-2Φ 510 ( ) Φ =-Φ ( ) Φ ( ) Φ =Φ =-1.732Φ 270 ( ) Φ =-Φ -60 ( ) Φ =0 According to algebraic calculations to the data in table 1and as a result of graphically calculation of wavefor in Figure 5, total agnetic flux wavefor is considered in Figure 6. Figure 4. The distribution of agnetic flux lines Ф A, Ф B, Ф C in the values of I a =I ax, I b =I ax, I c =I ax. The sae way as it is agnetic flux line propagation of B and C phases are not shown for not having coplex the shape. Clearly, phase B and C can be including with a specific phase shift which assue for A phase. Magnetic flux lines coposed by each of three phases are presented in Figure 4. In this figure, lover part of closing ferroagnetic aterials of flux is shown to avoid coplex shape. As linear asynchronous otors fed by three-phase sinusoidal current, agnetic flux will vary with the sine law. In other words; sint (1) A sin( t 120 ) (2) B C sin( t 240 ) (3) It will describe. We can calculate the phase flux which values corresponding to these values with t arguent by giving different values. In this way; ωt =0, φ A =0 φ -B =-φ ω.sin(-120 )=0.866φ φ C = φ.sin(120 )=0.866φ T A ( B ) C (4) ( ) Figure 5. The distribution of agnetic flux lines Ф A = Φ sin(t), Ф B =Φ sin(t+120), Ф C =-Φ sin(t) Figure 6. Wave diagra of Ф=(Ф A +Ф C -Ф B )=Ф sin(t+) Figure 7. Ф=Ф sin(t+) space diagra of the agnetic field and direction of progress If reflected spaces which seen in Figure 3 is taken into account, area for that shown in the Figure 7 can be obtained. This oving field is consist of the su of two fields according to wt axis. 56

4 International Journal on Technical and Physical Probles of Engineering (IJTPE), Iss. 19, Vol. 6, No. 2, Jun Envelops of these areas has been liited with sinuslike, one of the(see above section) is ferroagnetic layers that ake up rotor of the otor, the other(see the following section) are covering the agnetic circuit of the stator is able to wave with the V speed (Figure 8). V 2 f (1 S) (1 S) (5) a where: a (c) Figure 8. The appearances of the walking agnetic field for different occasions in linear induction otor. without rotor, use of diaagnetic aterial as rotor, (c) use of ferroagnetic aterials and aluinu as rotor; 1- Ferroagnetic core, 2- Aliinu layer, 3- ferroagnetic layer, 4- bronze layer Due to the assence of paper constitute the atheatical and graphical odeling; one further additional of paper the chapter is not necessary. III. CONCLUSIONS 1. In the literature, otion of the lineer otors explained within the fraework of electroagnetic wave theory. In this case, exaination of the field changes, the driving force and synchronous speed coe to light soe probles. Explanation of this proble according to electroagnetic wave theory is not sufficent. 2. The evaluation of lineer otors theory in ters of agnetic field theory will allow the solution of any probles. Description of oving agnetic field which it is active in lineer otors odeled as siilar to the general theory of induction otor. His approach is allow that creating equivalent agnetic circuit of lineer otor, deterining the graphically and analytically the change of the agnetic field in different parts of rotor and stator phase. 3. Exaination ethod suggested in the article can be used in the design of the linear electric otors, deterination of the characteristics and laboraatory experients. 4. Approach is presented the ideas of the authors and is open to debate. REFERENCES [1] P. Trobetta, The Electric Haer, AIEE Conv., Chicago, NY, [2] B.D. Sadovskiy, Moving back and forth as a Mechanical Inspection of Induction Motor, Journal of Vestnik Elektro-proishlennosti, No. 7, pp , 1940 (in Russian). [3] G.I. Sturan, Induction Machines with Open Magnetic Circuits, Elektricestvo dergisi, No. 10, Russia, [4] G.I. Sturan, P.L. Aponov, Outdoor Edge Effect Magnetic Core Induction Motors, Elektrijestvo, No. 2, pp , 1947 (in Russian). [5] I.M. Postkinov, L.P. Nijnik, et al., Calculation of Electroagnetic Fields Trigger Multi-Tier Environent SUSPENSION, Journal of Elektrijestvo, No. 9, pp. 1-7, 1965 (in Russian). [6] O.N. Veselovskiy, A.Y. Konyaev, F.N. Sarapulov, Lineer Asenkron Motorlar, Energoatoizdat, Moskova, 1991 (in Russian). [7] Y.F. Gieras, Lineer Induction Drivers, Clarendon Press, Oxford, 1994 [8] T. Saudauscas, A. Silgevicus, Z. Savickiene. Distribution of Magnetic Field of Linear Induction Motor, Electronics and Electrical Engineering, Vol. 4, No. 16, pp , [9] M.M. Sokolov, L.K. Sorokin, Electrical Drive Systes with Linear Asynchronous Motors, Energia, Moscow, 1974 (in Russian). [10] S. Yaaura, Theory of Linear Induction Motors 2nd Edition, University of Tokyo Press, Tokyo, Japan, BIOGRAPHIES Arif Meedov was born in Baku, Azerbaijan, in He received the B.Sc., M.Sc. and Ph.D. degrees fro Azerbaijan State Oil Acadey, Baku, Azerbaijan all in Electrical Engineering, in 1967 and 1970, respectively. Currently, he is a Professor of Electric Engineering at Inonu University, Malatya, Turkey. Teyuraz Abbasov was born in Karabag, Azerbaijan, in He received the B.Sc. and the M.Sc. degrees fro Moscow Auto Mechanical Institute (Moscow State Technical University, MAMI) and the Ph.D. degree fro Azerbaijan State Oil 57

5 International Journal on Technical and Physical Probles of Engineering (IJTPE), Iss. 19, Vol. 6, No. 2, Jun Acadey and Azerbaijan National Acadey of Sciences, Baku, Azerbaijan all in Electrical Engineering, in 1981 and 1991, respectively. Currently, he is a Professor of Electrical Engineering at Inonu University, Malatya, Turkey. He is also an acadeic eber of Aerican Cheical Society and the World Scientific, Engineering Acadey and Society (WSEAS), and Meber of Scientific Coittee of the Virtual For CEAM-VF He is a eber of editorial broad of the International Review on Cheical Engineering (IRECHE). His research interests are in the area of electroagnetic fields and technology, agneto hydro dynaics and agnetic fluids, bio-electroagnetics. Mustafa Seker was born in Istanbul, Turkey, in He received the B.Sc. and M.Sc. degrees in Electrical and Electronically Engineering in 2006 and He is a Ph.D. student in Electrical Engineering at Inonu University, Malatya, Turkey. Besides, he is working in Divrigi Nuri Deirag Vocationaly High School, Cuhuriyet University, Sivas, Turkey. 58