Australian Journal of Basic and Applied Sciences

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1 Austalian Jounal of Basic and Applied Sciences, 7(14) Decembe 13, Pages: 5-58 AENSI Jounals Austalian Jounal of Basic and Applied Sciences Jounal home page: Development of Induction Moto Efficiency Model and Impoving At ow oad Condition Using Atificial Intelligence 1 D. Santhosh Kuma, D.D.Manamalli, 3 O.T. Shamina 1 Reseach Scholo, MIT campus, Anna Univesity, Tamilnadu, India. Associate Pofesso, MIT campus, Anna Univesity, Tamilnadu, India. 3 PG Scholo,VIETW, Eode, India. ARTICE INFO Aticle histoy: Received 13 Novembe 13 Received in evised fom Decembe 13 Accepted 3 Decembe 13 Available online 1 Febuay 14 Keywods: Induction Moto, Mathematical Model, osses calculation, Efficiency model. ABSTRACT Induction moto is the electical dives which ae widely used in majo industial applications. Geneally efficiency of the induction moto is poo at lowe load condition. It is necessay to impove the efficiency fo the bette pefomance that is possible with the modeling of an induction moto. In this wok the mathematical model of an Induction Moto is developed. Fom the paametes obtained fom the model, efficiency can be calculated fom no load to full load condition consideing all moto losses including Stay loss, Fiction loss etc. Efficiency has been impoved by using conventional and atificial intelligent technique like FUZZY logic. The pefomance of developed induction moto model is analyzed with vaious paametes like toque, speed, cuent and vaious losses. 13 AENSI Publishe All ights eseved. To Cite This Aticle: D. Santhosh Kuma, D.D.Manamalli, O.T. Shamina., Development of Induction Moto Efficiency Model and Impoving At ow oad Condition Using Atificial Intelligence. Aust. J. Basic & Appl. Sci., 7(14): 5-58, 13 INTRODUCTION The utility of induction moto is moe than 5% in the electical enegy geneation woldwide. A small impovement in efficiency would significantly save the total electical enegy. Hence, it is impotant to optimize the efficiency of moto dive systems if significant enegy savings ae to be obtained. The induction moto (IM), especially the squiel-cage type, is widely used in electical dives and is esponsible fo most of the enegy consumed by electic motos. The main objective of the poject is to develop the mathematical model of an Induction Moto fo calculating the efficiency fom no load to full load condition. The efficiency of the induction moto must be analyzed deeply ove the vaious opeating egions. Fom the analysis, efficiency of the induction moto is less accuate ove some opeating egion. This wok involves only in obtaining the efficiency model of induction moto including all the losses fo vaious load conditions. Geneally efficiency of the moto will be poo at low load conditions. Induction moto cannot be opeated at full load condition in all applications, fo example taction, electic vehicle etc. In many applications efficiency optimization of induction moto (IM) which is the most used electical moto pesents an impotant facto of contol especially fo autonomous electical taction. Induction moto is well explained in Bimal k. Bose (3), Efficiency calculation model can be studied in the pape pesented by Cui shumei, iang chen, Song liwei (8). In this wok, Section explains the development of mathematical model of Induction Moto using stato efeence fame. Section 3 deals with calculation of losses. Section 4 deals with the detemination of efficiency model. Section 5 explains about the esults and analysis. Section 6 is the conclusion. Development of Mathematical Model of Induction Moto Using Stato: Refeence Fame: Induction moto model can be developed by using diffeential equations of the induction moto, thee ae six mathematical equations fo developing the model of the induction moto which ae as follows. di ( mr + R ) P ds s m m = is + ψ q + ψ dω as as as R Vds + a s (1) Coesponding Autho: D. Santhosh Kuma, Reseach Scholo, Depatment of Instumentation Engineeing, Madas Institute of Technology, Anna univesity, Tamilnadu, India , santhoshkuma86@gmail.com

2 51 Santhosh Kuma et al, 13 Austalian Jounal of Basic and Applied Sciences, 7(14) Decembe 13, Pages: 5-58 di ( R + R ) P qs m s m m = ids + ψ d ψ qω a a s as s R Vqs + a s () dψ d = mr i ds + R ψ d P ψ qω (3) dψ q = mr i qs R ψ q + P ψ d ω (4) dω 3Pm = 4 J ( ψ i ψ i ) d qs q ds Tl J Bω J (5) dt e 3P = 4 m ( ψ i ψ i ) d qs q ds (6) Whee ids - stato d-axis cuent, iqs -stato q-axis cuent, ψ d - Roto d-axis flux inkage, ψ q - Roto q- axis flux inkage, Inductance, a - constant, ω - Roto speed, T e - Developed Toque, m - Magnetizing inductance, R - Roto esistance, B - Fiction coefficient, P - No of poles, J - Moment of Inetia s - Stato Fo developing induction moto model, vecto model is the best way, because vecto model decouples the inteaction between the flux and toque. Nomally, in dc sepaately excited moto flux and toque can be contolled independently because thee is natual decoupling between the flux contol quantity and toque contolling quantity. Constuction wise amatue and field windings ae placed othogonal to each othe but in ac moto this is not thee, so always thee is a inteaction between the stato cuent and oto toque. In the gaph, 85 sampling instants ae taken fo moto stating condition; moto eaches its ated speed afte 85 sampling instants. V/F contol has been applied fo moto stating in ode to educe the stating cuent which can be educed futhe by educing the step incease in V/F atio. When V/F atio is educed, stating time of moto will also incease. Fo calculating moto paametes at diffeent load conditions, load toque which vaies at diffeent time instants is taken as load vaiable. Vaiation in the load cuent, flux linkage, speed, and developed toque has been plotted in the figues below. Vaiation in the q-axis and d-axis cuent at vaious load conditions ae shown in Fig1 1 1 Id(A) Iq(A) Fig. 1: Stato d-axis cuent. Fig. : Stato q-axis cuent. The flux linkage of the moto is constant fo load vaiation. Fo the stating of moto, V/F contol is applied so stating flux linkage value will be lowe. When the load is inceasing moto speed will stat to educe. The eduction in the moto speed is plotted in Fig3. Hee low loads ae applied so eduction in the speed will be less.

3 5 Santhosh Kuma et al, 13 Austalian Jounal of Basic and Applied Sciences, 7(14) Decembe 13, Pages: Speed(RPM) 1 5 Fig. 3: Moto speed Developed toque of the moto is plotted in the Fig4, wheeas the Output powe of the moto which is calculated fom the speed and toque of the moto is shown in the Fig.5 toque(n-m) output powe(watts) Fig. 4: Developed toque. Fig. 5: Output powe of the moto. Diffeent types of losses pesent in Induction moto ae 1. Coe oss (constant loss). Coppe oss (I R loss, Vaiable loss) 3. Fiction and Windage osses (Mechanical losses) 4. Stay loss Total oss = P c + P cus + P cu +P fw +P s (7) Coe loss: Coe loss is a constant loss, i.e. it will not change when the load is changing. The coe loss of moto is diectly popotional to supply voltage. The coe loss of a induction moto depends upon the fequency and the maximum flux density when the volume and thickness of the coe lamination ae given. The coe loss can be educed by educing the supply voltage. Coe oss contains two components which ae as follows, Eddy cuent loss: Eddy cuent loss is occuing due to flow of ciculating cuent in the moto coe, this ciculating cuent can limited by laminating the moto coe, the eddy cuent loss is occuing in the fom of heat. P e αf B (8) f =opeating fequency, B =Max.flux density Hysteesis loss: Hysteesis loss is occuing due to the magnetic popety of the coe mateial, due to the satuation of the mateial hysteesis loss occus in the fom of heat. P h αfb 1.6 (9) Fo educing the coe loss we can adjust supply fequency, flux density and supply voltage, coe loss occu due to flow of I w (coe loss cuent) though the R (coe loss esistance),the no load cuent of the moto is combination of the I w +I μ. When we educe the magnetizing cuent by adjusting the voltage coe loss can be educed. Nominal values, fo 1 to 1 HP motos, 1. Thickness of the lamination can be vaying in between.3mm to.5 mm based on the moto atings.. Flux density can be vay in between.3 wb/m to.45wb/m

4 53 Santhosh Kuma et al, 13 Austalian Jounal of Basic and Applied Sciences, 7(14) Decembe 13, Pages: 5-58 Coe loss is the combination of eddy cuent and hysteesis loss. In this wok V/F contol is applied at stating of moto so both the flux density and fequency will be inceased gadually upto ated speed afte eaching ated speed it will become constant iespective of load conditions. Eddy cuent is shown in the Fig6, Hysteesis loss is shown in the Fig7 Eddy cuent loss(watts) Hysteesis loss(watts) Fig. 6: Eddy cuent loss. Fig.7: Hysteesis loss. Coppe oss: Coppe loss vaies as a function of load cuent. Wheneve load is applied to the moto coppe loss also will change. In squiel cage induction moto nomally tuns atio is taken as 1, because due to shot cicuit on the oto side oto no of tuns will eplicate stato no of tuns, so in squiel cage induction moto stato and oto cuents ae consideed as equal in magnitude. Due to this stato and oto coppe loss will be same in magnitude. Coppe oss contain two components they ae, Stato coppe loss: Stato coppe loss is diectly popotional to the supply o stato cuent of moto, this stato cuent can be measued diectly at stato side so calculation of this loss is easie. When load is inceasing load cuent also will incease so this coppe loss also will incease. P cus =I s *R s (1) Roto coppe loss: Roto coppe loss is diectly popotional to the oto cuent. Measuement of oto cuent is not so easy as stato cuent measuement. The easiest way to measue oto cuent is tuns atio. Roto coppe loss can be calculated by measuing the slip value, since oto loss is popotional to slip speed. When slip value is low, oto coppe loss will be less. One way to educe oto coppe loss is by contolling the speed of induction moto. P cu =I *R (11) Total coppe loss P cu = I s Rs+I R I s stato cuent. R s stato esistance. I oto cuent. R s oto esistance. Hee stato and oto coppe losses ae calculated fo pe phase value of cuent. Fo total coppe loss, it is necessay to multiply with no of phases. Stato coppe loss is shown in the Fig8 and oto coppe loss is shown in the Fig9 fo vaiations in the load. Total coppe loss is the addition of stato and oto coppe loss 15 1 stato cu loss(watts) 1 5 Roto cu loss(watts) Fig. 8: Stato coppe loss Fig. 9: Roto coppe loss.

5 54 Santhosh Kuma et al, 13 Austalian Jounal of Basic and Applied Sciences, 7(14) Decembe 13, Pages: 5-58 Fiction and Windage osses: Fiction and Windage losses ae mechanical losses pesent in the moto, fiction loss occus due to the fiction in moto pats like beaings. Windage loss occus due to the wind opposition fo moto otation. Accoding to IEEE standad fiction loss will be 1% of output powe fo 5HP moto. This standad value vaies based on the moto powe ating. Fiction and windage loss is shown in the Fig1. fiction&windage loss(watts) Fig. 1: Fiction and windage loss Stay oss: The stay loss could be calculated by the following way. Both the pulsation loss P t and the hamonic loss P B ae in popotion to the stato cuent I 1. The suface loss is popotional to the squae of stato cuent. The sum of the pulsation loss and the hamonic loss equals the suface loss appoximately, and hence it is deduced that the sum of pulsation loss, hamonic loss and suface loss ae occupied 5% of the total stay loss. Stay loss is the combination of five losses such as Suface loss, Pulsation loss, Hamonic cuent loss of oto pat, Coss path loss, and Flux leakage loss. P st =P stf *(I st /I stf ) (1) P st =stay loss at opeating load. P stf =stay loss at full load. I st =load cuent at opeating load. I stf =load cuent at full load. Stay loss of the moto is vaying when the load is vaying. Stay loss is the function of load cuent. Vaiation in the stay loss is shown in the Fig11 and Total loss of the moto is shown in the Fig1 15 Stay loss(watts) 1 5 Total loss(watts) Fig. 11: Stay loss Fig. 1: Total loss. Input powe is nothing but output powe plus losses. Following gaph Fig13 shows the Input powe to the moto. 5 Input powe(watts) Fig. 13: Input powe Development of Efficiency Model: Pefomance of induction moto can be analyzed by calculating the efficiency of the moto knowing the input and output of the moto. But when one of these paametes is unknown, by calculating losses unknown can be infeed. In this wok input powe to the moto is unknown since Powe facto of the moto is not known, so

6 55 Santhosh Kuma et al, 13 Austalian Jounal of Basic and Applied Sciences, 7(14) Decembe 13, Pages: 5-58 by calculating output powe and losses, input powe is calculated. Efficiency can be calculated by using the fomula. OUTPUTPOWER EFFICIENCY = OUTPUTPOWER + OSSES (13) Efficiency of the moto vaies as load vaies, when the applied load is low, efficiency of the moto becomes less. As load inceases, efficiency also will stat to incease. Efficiency of the moto is calculated fo vaiations in the load which is less than half of the ated load. It is possible to find efficiency upto full load condition. Fig14 shows the efficiency at low load condition. Fig. 14: Efficiency of moto in open loop. Methods fo Efficiency Impovement: Efficiency has been impovement in two methods 1. Conventional method using PID.. Fuzzy optimization technique. Conventional Method: Nomally efficiency can be impoved in two methods, 1. Powe facto impovement method ( fo low load condition). Constant speed contol method (fo highe load condition) At the low load condition the majo pat of the loss is coe loss, the coe loss of the moto can be educed by educing the magnetizing cuent of the moto. Cause fo coe loss is magnetic satuation of the moto windings. If the supply voltage to the moto is educed at low load condition, the eactive cuent taken by the moto will be educed and eal cuent will be inceased in ode to make appaent cuent emains same and the powe facto also inceases. But voltage should not be educed below cetain limit. Fig. 15: Conventional PID contol scheme.

7 56 Santhosh Kuma et al, 13 Austalian Jounal of Basic and Applied Sciences, 7(14) Decembe 13, Pages: 5-58 Fig. 16: Magnetizing cuent component. Fig. 17: Coe loss cuent component. Fig. 18: Powe facto. Fig. 19: Speed of the moto. Fig. : Efficiency in conventional contol. Fuzzy ogic Contol Scheme: Fuzzy contolle is acting in supevisoy mode fo poviding set point to contol the diect axis cuent. The fuzzy logic is an aggegation of ules, based on the input state vaiables condition with a coesponding desied output. Accoding to the optimization pinciple, two input vaiables ae consideed toque cuent component I ds and its integal squae vaiation. The output of the fuzzy contolle is the no load I, which is calculated to minimize ion losses. A simplified block diagam of the optimization pocedue is depicted in Fig 1.

8 57 Santhosh Kuma et al, 13 Austalian Jounal of Basic and Applied Sciences, 7(14) Decembe 13, Pages: 5-58 Fig. 1: Block diagam of the optimization contol system. Fig. : Magnetizing cuent component. Fig. 3: Coe loss cuent component. Fig. 4: Powe facto in fuzzy contol. Fig. 5: Speed of the moto. Fig. 6: Efficiency in fuzzy contol. Pefomance Analysis of Conventional and Fuzzy Contolle: The following table shows the pefomance of conventional contolle as well as pefomance of fuzzy optimization whee fuzzy contolle acting in supevisoy mode and PID in egulatoy mode.

9 58 Santhosh Kuma et al, 13 Austalian Jounal of Basic and Applied Sciences, 7(14) Decembe 13, Pages: 5-58 PARAMETER CONVENTIONA CONTROER FUZZY OPTIMIZATION SUPPY VOTAGE 43 V 48 V STATOR D-AXIS CURRENT 3A.7A POWER FACTOR.7.74 MAGNETIZING CURRENT. to to 1.54 CORE OSS COMPONENT to 1.6 to 1.64 EFFICIENCY 6% 6.5% Fom the table above it is clea that efficiency of the induction moto is impoved by using fuzzy contolle in supevisoy mode, thus poves that fuzzy optimization has bette contol pefomance when compaed to conventional contolle. Conclusion: The efficiency model of the induction moto is developed by modeling the induction moto using vecto model. Fom the developed induction moto model, output paametes(cuent,flux linkage,speed and toque) ae obtained. By using those output paametes vaious losses of induction moto ae calculated. In that Coe loss is calculated using maximum flux density fom flux linkage and coppe loss fom output cuent. The output powe and calculated losses of the moto gives the Input powe theeby efficiency of the induction moto is calculated at lowe load conditions. Using conventional and Fuzzy optimization techniques efficiency is impoved by minimizing losses. Fom the simulation esults it is poved that in the efficiency maximization, fuzzy contolle has bette pefomance than conventional contolle. REFERENCES Bimal, K. Bose, 3. Moden powe electonics and ac dives. Peason education, Thid edition, pp: 9-94, Cui Shumei, iang Chen, Song iwei, 8. Study on efficiency calculation model of induction moto fo electical vehicles. IEEE Vehicle Powe and Populsion Confeence (VPPC), Septembe 3-5. Jawad Faiz and M.B.B. Shaifian, Optimum Design of a Thee phase Squiel cage induction moto based on Efficiency maximization, 1(5): Muat Baut, Seta Bogosyan, Metin Gokasan, 7. Speed-sensoless Estimation fo Induction moto using Extended kalman filtes. IEEE Tansactions on industial electonics, 54(1). Singh, G.K. and S.A.S. Al Kazzaz, 3. Induction machine dive condition monitoing and diagnostic eseach a suvey. Electic Powe Systems Reseach, 64(): Vilas N. Ghate, Sanjay V. Dudul and G.M. Dhole, 8. Genealized model of thee phase induction moto fo fault analysis.ieee Region 8 Sibicon.