MODELING OF SEPIC FED PMBLDC MOTOR FOR TORQUE RIPPLE MINIMIZATION

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1 ODEING OF SEPIC FED PBDC OOR FOR ORQUE RIPPE INIIZAION N.kshmipriy.E.,Assistnt Professor Deprtment of EEE Jy Shrirm Group of Institution, irupur, Indi S.nivel.E.,Assistnt Professor Deprtment of EEE Jy Shrirm Group of Institution irupur, Indi N.Sdeesh.E., Assistnt Professor Deprtment of EEE Jy Shrirm Group of Institution irupur, Indi Astrt BDC otor suffers from ommuttion torque ripple, whih minly depends on sttor winding impedne, speed nd trnsient line urrent in the ondution intervl. his pper desries novel iruit topology nd d input link voltge ontrol strtegy to keep inoming nd outgoing phse urrents hnging t the sme rte during ommuttion intervl. A SEPIC (single-ended primry indutor onverter) nd swith seletion iruit re employed in the front of the inverter. he desired ommuttion voltge is otined y the SEPIC onverter. he input d link voltge ontrol strtegy is rried out y the swith seletion iruit to seprte two proedures, djusting the SEPIC onverter nd regulting speed. he ommuttion torque ripple is nlyzed, nd introdued the wy to otin the desired d link voltge in detil. Finlly, simultion nd experimentl results show tht, ompred with onventionl nd the proposed method n otin the desired voltge is otined nd minimize ommuttion torque ripple more effiiently. Keywords- Brushless DC otor, orque ripple, I. Introdution BDC otor is type of Synhronous otor. his mens mgneti field generted y the sttor nd mgneti field generted y the rotor rottes t the sme frequeny. DC motor lso known s eletronilly ommutted is synhronous eletri motors powered y diret urrent eletriity nd hving eletroni ommuttion systems, rther thn mehnil ommuttors nd rushes. he urrent-to-torque nd voltge to speed reltionships of BDC motors re liner. HE rushless d motor (BDC) hs een widely used in industril fields tht require high reliility nd preise ontrol due to its simple struture, high power density, nd extended speeding rnge [] [3]. he performne of suh motors hs een signifintly improved due to the gret development of power eletronis, miroeletronis, mgneti performne of mgnets, nd motion ontrol tehnology in reent yers [4] [9]. BDC motors my e desried s stepper motors with fixed permnent mgnets nd possily more poles on the sttor thn the rotor. he ltter my e without permnent mgnets, just poles tht re indued on the A SEPIC is similr to trditionl uk-oost onverter, ut hs dvntges of hving non-inverted output (the output hs the sme voltge polrity s the input), using series pitor to ouple energy from the input to the output (nd thus n respond more grefully to short-iruit output), nd eing ple of true shutdown. When the swith is turned off, its output drops to V, following firly hefty trnsient dump of hrge when suh lrge horsepower drives re needed []-[]. SEPIC onverter nd swith in series with eh phse re proposed for driving permnent mgnet rushless d motor. he SEPIC onverter is designed to operte in the disontinuous ondution mode for opertion with n supply. In this opertion mode, the line urrent follows the line voltge wveform to ertin extent. he d link voltge ontrol strtegy is rried out y the swith seletion iruit to seprte two proedures, djusting the SEPIC onverter nd regulting speed he pper is orgnized s follows DC link voltge ontrol strtegy to keep inoming nd outgoing phse urrents hnging t the sme rte during ommuttion to ontrol of torque ripple. he desired ommuttion voltge is omplished y the SEPIC (Single-Ended Primry Indutor Converter). SEPIC onverter nd swith in series with eh phse re proposed for driving permnent mgnet rushless d motor. he SEPIC onverter is designed to operte in the disontinuous ondution mode for opertion with n supply. In this opertion mode, the line urrent follows the line voltge wveform to ertin extent. he d link voltge ontrol strtegy is rried out y the swith seletion iruit to seprte two proedures, djusting the SEPIC onverter nd regulting speed. II. BRUSHESS DC OOR he extrtion of torque nd ripple requires the mthemtil model. In three phses sttors winding the phse vrile re given. [ v ] [ R][ p[ ][ [ e] () Where vetors, ISSN (Print) ISSN (Online)

2 [ v] [ [ e] [ v v [ i [ e i i v ] e e Here the resistne nd indutnes re given y R [ R ] R,[ ] R Assuming symmetril struture of the indutne [ v] ' [ ] where [ R][ P[ ][ [ e] In three phse system without neutrl I +I +I =,hene the motor urrent eqution my e written he set of differentil equtions mentioned defines the developed model in terms of the vriles nd times s n independent vrile. he torque ripple is generted due to the urrent ripple. his urrent ripple is depends on the sttor winding impedne nd k eletromgneti fore. P[ where, '' [ ] ] '' [ ] ( {[ V ] ) [ R][ ( l ) [ e]} he eletromgneti torque ( e ), is ], ] ( ) e e i e i e i W * * * m (2) he motion eqution of the BDC motor, dw d B t t e t (3) J Numer of Pole : 6poles III. DESIGN OF SEPIC CONVERER FEED WIH BDC OOR he proposed onverter with four ontrolled swithes nd diode the frontend onsists of SEPIC d/d onverter omprised of indutors nd 2, swith S, intermedite pitor C, diode D A nd output pitor C 2.. Figure.show tht Ciruit Digrm of he diodes D A, D B nd D serve to free wheel the winding urrents when the swithes re turned off during urrent regultion nd phse ommuttion. he output of the onverter is used to energize the three phses of the motor, nd the for proper demgnetiztion of the phse fter eh ondution intervl nd to prevent ondution during periods of negtive k-ef, the instntneous vlue of V C should e greter thn the pek vlue of the k-ef, voltge of pitor C is used to demgnetize the phses during turn-off nd for urrent ontrol. V C >E By pplying Kirhhoff s voltge lw to the SEPIC front-end, we otin V IN =V +V C +V 2 Sine the verge voltges in the two indutors re zero, we get V IN =V C E mx =V in ssuming tht the ripple in the intermedite pitor voltge is negligile. he mximum operting speed is then given y Ω mx =V in /K e, where K e is the phse k-ef onstnt of the motor. he front-end SEPIC onverter n e designed for opertion either in the ontinuous ondution mode in the disontinuous ondution mode. In CC, its voltge onversion rtio is given y. SPECIFICAION OF BDC OOR he mhine detils of BDC motor re given elow. Rted Power : 6W Rted Voltge : 48V DC Rted Speed : 45rpm Where, D is the duty yle of the swith S in DC, its voltge onversion rtio is given y Where, K=2 2 /R( + 2 ),R eing the equivlent lod resistne nd the time period of swith S.he oundry vlue of K etween ontinuous nd ISSN (Print) ISSN (Online)

3 disontinuous ondution modes, K rit n e lulted (m=m d ) s K rit = (-D) 2 he onverter opertes in CC when K > K rit nd in DC when K < K rit. In oth modes of opertion, V d n e regulted t vlue higher (Boost opertion) or lower (Buk opertion) thn the input voltge V in. From the ontrols viewpoint, it is dvntgeous to hve the onverter operting in the sme mode under ll lod onditions. IV. SIUAION RESUS In this hpter desries mthemtil model of BDC motor, nd simultion model of SEPIC onverter, this mthemtil model n e onverter in to eletril model y using ple trnsform. With the use of this proposed method to get sinusoidl wveform nd torque ripple n e redued. Figure 2.show tht modeling of BDC with SEPIC onverter In rushless d motor, the rmture urrent is ommutted; the urrent ripple is generted due to the sttor winding indutne nd devition of k eletromgneti fore. he torque ripple is generted due to the urrent ripple. his urrent ripple is depends on the sttor winding impedne nd k eletromgneti fore Figure 3.show tht Bk EF of BDC otor 2 ISSN (Print) ISSN (Online)

4 Figure 4.show tht Voltge Wveform of BDC otor he urrent ripple n e redued y supplying the pproprite mgnitude of input voltge for free-wheeling period. his onsists of lot of distortion. he torque ripple is generted due to the urrent ripple. his urrent ripple is depends on the sttor winding impedne nd k eletromgneti fore. Fig.6 show tht Output Voltge for hree Phse Inverter he three phse urrent of Input voltge vrying method for rush less d motor hs een simulted. At strting time the distortion is high. When.2 se, the distortion will e reduing. he urrent ripple n e redued y mintining urrent onstnt in freewheeling region. If the urrent of phse is onstnt when the ommuttion is ourred from phse C to phse A, the urrent ripple is not produed. V. HARDWARE SEUP FPGA sed sensor ontrol of rushless DC motor in minimizing the hrmonis used y torque ripple in the system. Here the is introdued etween inverter nd retifier. For the proper ommuttion nd ontrol of the BDC motor n FPGA ontroller is used in it. Figure 5.show tht orque nd Speed wveform of BDC otor his pulsting torque will e redued y input voltge vrying method. he figure 5 shows tht rotor speed torque hrteristis of BDC motor. he wve form is not uniformly in nture. Figure 6. Blok Digrm of Hrdwre Setup he single phse 23 volt AC supply is fed to the retifier. It is onverted into d using the retifier nd fed s 3 ISSN (Print) ISSN (Online)

5 input to the SEPIC onverter. SEPIC onverter fed to the OSFE inverter, Inverter swithes re ontrolled y using the FPGA ontroller nd driver through Optoisoltor, whih fed to BDC motor. FPGA onsists of gtes iruit, whih fed to driver iruit. Seprte supply is fed to the proessor nd emedded C progrm is fed to generting PW pulses. Power Supply is the devie tht trnsfers eletri power from soure to lod using eletroni iruits Figure 8.shows tht Output Voltge Wveform of Inverter he three phse output voltge wveform of voltge soure inverter is tken from digitl nlyzer, In inverter opertion, if the swithing ngels lulted for the equl-d-soure se is pplied to the onsidered unequl se. Oviously, y effetively solving the hrmonis elimintion prolem with lrge numer of swithing ngles, the SHE-PW method n generte high-qulity voltge wveforms s well s less swithing frequeny s ompred to other modultion tehnique. Figure 7.shows tht Experimentl Setup of Hrdwre VI. HARDWARE RESUS he proposed SEPIC onverter sed sheme for BDC otor drive is experimentlly implemented using FPGA ontroller ord IR2 for lortory 6W BDC otor. he hrdwre result from the prototype suh s input nd output voltge wveforms, urrent wveform nd Hrmonis wveform re shown elow. Hrdwre prototype minly onsists of inverter series with SEPIC onverter fed BDC motor. In this hpter held on different onventionl wveforms nd proposed wveforms, these wveforms re otined y Digitl Anlyzer. orque ripple n e lulted y ompre onventionl method to proposed method. Figure 9.shows tht Output Comined Voltge Wveform of Inverter 4 ISSN (Print) ISSN (Online)

6 Figure 2.Show tht Phse Current of BDC otor without Figure.Shows tht Output Comined Current Wveform of Inverter he phse voltge onsists of distortion due to turn on nd turn off of swithing proess (ertin hnge in urrent). he voltge ripple n e redued y SEPIC onverter. he d link voltge ontrol strtegy is rried out y the swith seletion iruit to seprte two proedures, djusting the SEPIC onverter nd regulting speed. In this projet SEPIC onverter series with inverter fed BDC motor Compred with the existing method, the proposed method n otin the desired voltge muh fster nd minimize ommuttion torque ripple more effiiently t oth high nd low speeds. Figure.Show tht Phse Voltge of BDC otor without he required torque n e produed y the initil urrent onstnt. When rmture urrent is ommutted, the urrent ripple is generted due to the sttor winding indutne nd devition of k EF. he urrent ripple leds to genertion of torque ripple. BDC motor does not mke onstnt speed. Figure 3.Show tht Phse Voltge of BDC otor with Figure 4.Show tht Phse Current of BDC otor with 5 ISSN (Print) ISSN (Online)

7 By ompre from without SEPIC onverter, the phse urrent onsists of lower distortion. Phse Current of BDC otor n e otined from Digitl storge osillosope. DC link voltge ontrol strtegy to keep inoming nd outgoing phse urrents hnging t the sme rte during ommuttion to ontrol of torque ripple. he desired ommuttion voltge is omplished y the SEPIC (single-ended primry indutor onverter) onverter. VII. CONCUION Compred to onventionl orque ripple ontrol method, SEPIC onverter sed method will led to lower torque ripple. As result, using the SEPIC onverter sed input voltge vrying method of rushless d motor will led to inresed effiieny. A new iruit topology nd ontrol strtegy hs een proposed to suppress ommuttion torque ripple of BDC. In this pper SEPIC onverter is pled t the input of the inverter, nd the desired d link voltge n e hieved y pproprite voltge swith ontrol. he swith ontrol seprtes the two proedures, djustment of SEPIC onverter, nd regultion of speed so tht torque n respond immeditely during trnsient. REFERENCES [] Y.-C. Son, K.-Y. Jng, nd B.-S. Suh, Integrted OSFE inverter module of low-power drive system, IEEE rns. Ind. Appl., vol. 44, no. 3, pp , y/jun. 28. [2] A. Sthyn, N. ilivojevi, Y.-J. ee,. Krishnmurthy, nd A. Emdi, An FPGA-sed novel digitl PW ontrol sheme for BDC motor drives, IEEE rns. Ind. Eletron., vol. 56, no. 8, pp ,Aug. 29. [3] Anndsthyn, (29) A Alinsst, (29) New orque Control ethod for orque Ripple inimiztion of BDC otors with Un-Idel Bk EF, IEEE rnstion Industril Eletronis., vol. 37, no.4, pp. 8/ 8/4. [4] New Approh for inimum-orque-ripple ximum-effiieny Control of BDC otor, IEEE rnstion Industril Eletron., vol. 48, no. 6, pp , [5] Cheng sung in, (25) Presented Diret orque nd Indiret Flux Control of Brushless DC otor, vol. 8, no. 6, pp , Nov. 25. [6] Dmodhn, (2) A Current Control Sheme with n Adptive Internl odel for orque Ripple inimiztion nd Roust Current Regultion, IEEE Power Applition, vol. 52, no. 2, pp [7] Doo-He Jung,(22) orque Ripple inimiztion in P Synhronous otors Using Itertive erning Control, IEEE rnstion Power Eletronis., vol. 22, no. 2, pp [8] Hifeng u, (24) BDC otor Sttor nd Rotor Iron osses nd herml Behvior Bsed on umped Shemes nd 3-D FE Anlysis, IEEE rnstion. Power Eletronis, vol. 5, no. 4, pp [9] Hung-Chihen, (2) FPGA-Bsed Novel Digitl PW Control Sheme for BDC otor Drives, IEEE rnstion Industril Eletronis, vol. 53, no. 2, pp [] Jin wen show, (2) Commuttion-orque-Ripple inimiztion in Diret-orque-Controlled P Brushless DC Drives, IEEE rnstion Industril. Applition, vol. IA-2, no. 4, pp [] Krthikeyn, (2) Operting orque Estimtion of High-Speed slot less Brushless DC hine Considering Power oss, IEEE rnstion Power Eletronis., vol. 9, no. 6, pp Biogrphy rs.n.kshmipiy ompleted her helor s Degree in Eletril nd Eletronis Engineering in Sri Rmkrishn Engineering College, Coimtore nd Post Grdute in Applied Eletronis from hrj Engineering College. She is urrently working s n Assistnt Professor in the Deprtment of Eletril nd Eletronis Engineering in Jy Shrirm Group of Institution, irupur r.s.nivel ompleted his helor s degree in Eletril nd Eletronis Engineering in Aruni College of Engineering, iruvnnmli nd Post grdute in power Eletronis nd Drives from KSR College of ehnology, iruhengode with GOD medl. He is urrently working s n Assistnt Professor in the Deprtment of Eletril nd Eletronis Engineering in Jy Shrirm Group of Institution, irupur. r.n.sdeesh reeived the Bhelor of Engineering in Eletril nd Eletronis Engineering from Vellr College of Engineering nd ehnology, hindl, Erode in 29., nd the ster of Engineering degree in Control nd Instrumenttion Engineering from Kongu Engineering College, Perunduri, Erode in 23. He is urrently working s n Assistnt professor in the Deprtment of Eletril nd Eletronis Engineering in Jy Shrirm Group of Institutions, irupur. 6 ISSN (Print) ISSN (Online)