PERFORMANCE PREDICTION OF A NEW CONNECTION FOR DUAL VOLTAGE OPERATION OF SINGLE PHASE CAPACITOR RUN MOTOR

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1 Journl o letril ngineering PRFORMANC PRDCTON OF A NW CONNCTON FOR DUAL VOLTAG OPRATON OF SNGL PHAS CAPACTOR RUN MOTOR H. H. Hny letril power nd hines Dept., Fulty o ngineering, Ciro University, Giz-gypt. Add.: letril power nd hines dept., Fulty o ngineering, Ciro University, Giz-gypt, ip Phone:( , Fx:( , e-il: Hny_Hssn@hotil.o Astrt: This pper desries the theory nd test results o new onnetion o Single-Phse Cpitor Run Motor (SPCRM or dul voltge opertion. A progr siulting the opertion o the new onnetion gives suiient results to illustrte its stedy stte perorne. The eets o the operting pitor on the perorne o the new onnetion re inluded. xperientl esureents re rried out on oth trditionl nd new onnetions or oprison nd veriition o siulting results. The greeent o experientl nd oputtionl results pproves the odeling o the new onnetion. Key words: Single phse indution otor, pitor run otor, dul voltge. Noenlture r 1 r 1 x 1 x 1 r x x x n s V H in winding resistne; uxiliry winding resistne; in winding lekge retne; uxiliry winding lekge retne; rotor resistne reerred to in winding; rotor lekge retne reerred to in winding; gnetizing retne; the eetive turns rtio o the uxiliry winding to the in winding; retne o pitor; otor speed in urrent; uxiliry urrent; supply urrent; high supply voltge; 1. ntrodution Single-phse indution otors re widely used euse o their ost, reliility nd roustness in opertion. A single-phse otor hs two unsyetril sttor windings (in nd uxiliry windings, nd squirrel-ge rotor. The in nd uxiliry windings re in spe qudrture nd onneted in prllel ross the single phse supply. A pitor is onneted in series with the uxiliry winding to produe suiient phse shit etween the in nd uxiliry urrents needed or produing n ellipti MMF through the ir-gp o the otor. This ellipti MMF produes the strting torque o the otor. Single phse pitor otors operte either s pitor run otor, where the uxiliry winding is pernently energized, or s pitor strt otor, where the uxiliry winding is swithed out o iruit y entriugl swith nerly t 75% o the otor ull lod speed, or inlly s pitor strt pitor run otor, where the vlue o the pitor is lrge during strting nd sll during running. The single phse pitor run otor (SPCRM is used or ny pplitions suh s heting, ventilting nd ir onditioning (HVAC lowers nd opressors. The SPCRM hs ny dvntges suh s oderted strting torque nd good running perorne (high out power, high power tor, high eiieny nd low supply urrent [1]. SPCRM otors or interntionl use re requently ed y dul voltge suh otors ple o opertion ro high voltge (040 V-50 Hz or low voltge ( V-60 Hz supplies. These otors re provided with two sets o in windings whih n e onneted in series or the high voltge opertion or in prllel or the low voltge opertion. n priniple, two sets o uxiliry windings n e provided or siilr series nd prllel onnetions. However, it is suiient prtilly to it single set o the low voltge uxiliry winding. For the low voltge opertion, the uxiliry winding is onneted diretly ross the supply vi the pitor. For the high voltge opertion, the uxiliry winding is onneted in prllel vi the pitor with one set o the in windings (T-onnetion i.e. the in windings t s n uto-trnsorer reduing the 1

2 Min Winding High Voltge Supply Journl o letril ngineering high supply voltge to the low voltge required y the uxiliry winding []. These types o otors suer ro the ollowing disdvntges: The loss the strting torque nd huing i the urrents pss through eh o the in windings sets in opposite diretions i.e. the orret onnetions o the terinls o the in windings sets ust e gurnteed. The use o dierent vlue o the pitor t low nd high voltges opertion to otin high strting nd rekdown torques (the pitne is inversely proportionl to the squre o the supply voltge, so the pitne hs to e the qudruple t the lower voltge in se o two sets o uxiliry windings [3]. The deteriorted hrteristis t high voltge in se o T-onnetion [3]. On the other hnd, ny reserhers [4-7] hve studied the stedy-stte opertion o three-phse indution otors when ed ro single-phse supply. Sith proposed new kind o winding onnetion ethod, ned Seihex onnetion, whih n ke three-phse indution otor operte syetrilly ro single-phse supply [4]. The single-phse indution otor with Seihex onnetion hs high eiieny nd power tor, ut its strting torque is low nd the strting iruit is oplex [5]. Nil [6] studied the perorne o three-phse indution otor operting ro singlephse supply with new eletronilly ontrolled pitor using n eletroni swith in series with ixed pitor to hieve iniu unlne o the otor phse voltges t ll loding onditions. Xiuhe Wng et l. [7] presented novel energy eiient single phse indution otor with three series-onneted windings nd two pitors. By suitle seletion o pitors, the urrents in three windings were pproxitely syetril, nd thus, the otor n operte pproxitely syetrilly ro single-phse supply. This pper presents n nlysis or the stedy stte perorne o new onnetion o the SPCRM or dul voltge opertion. The onigurtion o the new onnetion is shown in Fig. 1, where the pitor is onneted in prllel with the uxiliry winding nd the prllel ointion is onneted in series with the in winding ross the high voltge supply. This onnetion ould e used or dul voltge opertion (0V-110V s well s or supplying the SPCRM with the line-to-line voltge insted o the line-to-neutrl voltge o the se grid in se o issing the neutrl point. The pper inludes the eets o the operting pitor on the perorne o the new onnetion. The perorne o the new onnetion hs een tested nd opred with tht o the trditionl onnetion in the lortory y loding the SPCRM using dynoeter, nd the siultion results otined were proved experientlly. Auxiliry Winding Cpitor Fig. 1 The new onnetion o the SPCRM. Mthetil Model Fig. shows the equivlent iruit o the new onnetion o the SPCRM, sed on the doule revolving ield theory y Morrill [8]. Fig.3 shows the phsor reltionship etween the in nd uxiliry urrents during the stedy stte opertion o the new onnetion. Sine the uxiliry urrent lgs the in urrent then the resulting ellipti MMF o the sttor windings will rotte in the lokwise diretion ording to the windings onigurtion, nd hene the otor will rotte in the se diretion. t is known tht eh sttor winding produes pulsting MMF. This pulsting MMF ould e deoposed into two rotting MMFs, hving the se plitude nd speed ut rotte in opposite diretions (orwrd nd kwrd. Then the SPCRM hs our rotting MMFs in its ir gp, two orwrd MMFs nd two kwrd MMFs, onsequently eh sttor winding hs our indued voltges: two due to orwrd nd kwrd MMFs o eh winding. Aording to the winding onigurtion, where the in winding leds the uxiliry winding in the spe y 90 eletrilly, the indued voltges o the in winding used y orwrd MMFs led tht o the uxiliry winding y 90 nd onsequently the indued voltges o the in winding used y kwrd MMFs lg tht o the uxiliry winding y 90. The equtions representing the stedy stte equivlent iruit o the new onnetion re written in trix or s ollows:

3 Journl o letril ngineering V H r 1 x 1 J X R X R -J J X X R R X -J Fig. The equivlent iruit or the new onnetion o the SPCRM x 1 V H Fig. 3 The phsor reltionship o the in nd uxiliry urrents o the new onnetion VH r 1 (1 The solution o these equtions under ny operting ondition gives the in nd uxiliry urrents. Hene, ll the perorne hrteristis o the otor t this prtiulr lod point n e lulted using the ollowing equtions: s ( 1 1 r Jx r 1 1 Jx JX (r s Jx R JX r s J(X x 0.5JX (r ( s Jx R JX r ( s J(X x the orwrd equivlent ipedne o the rotor reerred to the in winding the kwrd equivlent ipedne o the rotor reerred to the in winding, the indued voltges in the in winding y its orwrd nd kwrd MMFs, the indued voltges in the uxiliry winding y its orwrd nd kwrd MMFs, the indued voltges in the uxiliry winding y orwrd nd kwrd MMFs o the in winding., the indued voltges in the in winding y orwrd nd kwrd MMFs o the uxiliry winding P g gp power T d developed torque ω s synhronous speed θ phse ngle o the in urrent θ phse ngle o the uxiliry urrent P T g ( d P ω g Where: s J( J( (R (R - - R R X X JX sin(θ ( JX θ (3 (4 3. Siultion Results The siultion o the new onnetion is rried out using pitor run single-phse indution otor with the ollowing speiitions: 175 W, 0 V, 50 Hz, 1440 rp, 1.5 A, nd 10 µf pitor. Tle1 gives the experientlly deterined preters o the otor equivlent iruit. The opertion o the new onnetion is studied y supply voltge o 380 V-50 Hz to the otor onigurtion shown in Fig. 1. Fig. 4 shows the developed torque versus speed urve o the new onnetion. t is oserved tht the otor hs suiient strting torque nd pproxitely 00% over lod pity. Fig. 5 represents the speed- urrents urves o the new 3

4 Journl o letril ngineering onnetion, it is notiele tht the uxiliry winding hs higher urrent thn tht o the in winding, ut the two urrents re sller thn their rted vlues (1.5 A within the norl operting speed rnge. Fig. 6 shows the vritions o the power tor nd input power versus otor speed. Within the norl operting speed rnge, it is oserved tht the otor hs pproxitely power tor o 0.8. This vlue n e onsidered high espeilly i opred with other types o single phse indution otors. Tle 1 quivlent iruit preters o the SPCRM Preter Vlue r 1 6 Ω r 1 4 Ω x Ω x Ω r 14.3 Ω x Ω x Ω Fig. 4 The developed torque versus speed o the new onnetion Fig. 6 The vritions o the power tor nd input power versus the speed 4. ets o the Operting Cpitor The stedy stte perorne o the new onnetion is investigted using dierent vlues o the operting pitor. Fig. 7 shows the siultion results onerning the vrition o the developed torque with the pitor vlues. t is seen tht high vlues o the pitor give high vlues o strting nd rekdown torques. Fig. 8 shows the speed power tor urves or dierent vlues o the pitor. t is oserved tht there is n iproveent in the power tor with the inrese o the pitor. The vritions o the supply urrent (in urrent with otor speed or dierent vlues o the pitor re shown in Fig. 9. The igure deterines the derese o the in urrent with the inrese o the pitor. The eet o the pitor on the uxiliry urrent is shown in Fig. 10. The igure shows tht high o pitors result in high vlues o the uxiliry urrent. The investigtion o the new onnetion with hnging the operting pitor proves tht there is signiint iproveent in the otor perorne t high vlues o the pitor exept the uxiliry urrent. Fig. 5 The speed- urrents urves o the new onnetion Fig. 7 The developed torque results t dierent vlues o the pitor 4

5 Journl o letril ngineering Fig. 8 The speed-power tor urves or dierent vlues o the pitor Fig. 9 The supply urrent versus speed or dierent vlues o the pitor Fig. 10 The uxiliry urrent versus speed or dierent vlues o the pitor 5. xperientl Results The new onnetion is tested nd opred with the trditionl onnetion in the lortory y ehnilly oupling the SPCRM to dynoeter, where the lod torque ould e eletrilly ontrolled. n the trditionl onnetion the uxiliry winding is onneted in prllel vi the pitor with the in winding ross the supply voltge. The new onnetion is investigted y pplying supply voltge o 380 V-50 Hz; while the supply voltge o the trditionl onnetion is 0 V-50 Hz. The operting pitor is held onstnt t 10 μf, whih is the reoended vlue or the otor opertion under norl onditions. Tle illustrtes the experientl results o the two onnetions t the se operting onditions. The oservtion o the results in Tle yields the ollowing relevnt points: The otor speed nd input power o the new onnetion re higher thn tht o the trditionl onnetion. The power tor o the trditionl onnetion hs lwys higher vlues thn tht o the new onnetion. The supply urrent o the new onnetion hs low vlues when opred with those o the trditionl onnetion round the ull lod onditions. The uxiliry urrent nd voltge, o the new onnetion, hve high vlues, ut they re still in the se rnge. The eiieny o the new onnetion is slightly lower thn tht o the trditionl onnetion. The experientl results presented in this setion indite tht the perorne o the new onnetion is stistory when opred with the perorne o the trditionl onnetion; espeilly when onerning the otor speed nd supply urrent. t n e oserved tht the results otined ro siultions irly gree with the results otined ro experientl tests o the new onnetion, nd the odel used is peretly vlidted. 6. Conlusions n this pper, new onnetion or operting the SPCRM ro dul voltge hs een explined theoretilly nd lso hs een proved y test. The investigtion o the new onnetion proved tht it hs stistory perorne when opred with the trditionl onnetion. Also it overoes the disdvntges o the trditionl onnetions or the dul voltge opertion o the SPCRM. Using the new onnetion, it is possile to hieve nerly the se perorne s in se o the trditionl onnetion with ordinry sttor windings nd se pitor or oth ses. Reerenes 1. Yedon W. H., Yedon A.W.: Hndook o sll eletri otors. MGrw-Hill,

6 Journl o letril ngineering. Ji Cox: letri Motors. p. 39-4, Argus Books Ltd Hns-Dieter Stölting, erhrd Kllenh, Wolgng Arhein: Hndook o Frtionl-Horsepower Drives, p , Springer Verlg, Berlin, Heidelerg, New York, Sith O. J. M.: Lrge low-ost single-phse SMHXTM otors. n: Trns. nergy Conversion, vol. 14, no. 4, De.1999, p Chn T. F., Li L., nd Yn L. T.: A oupled iruit nd ield nlysis o three-phse indution otor with the Sith onnetion. n: Trns. Mgnetis., vol. 4, no. 4, Apr. 006, p Nil A. A.: Three-phse indution otor operting ro single-phse supply with n eletronilly ontrolled pitor. n: letri Power Systes Reserh Vol. 73, 005, p Xiuhe Wng, Hui hong, Yuo Yng, nd Xiolei Mu: Study o novel energy eiient single-phse indution otor with three series-onneted windings nd two pitors. n: Trnstions on nergy Conversion, vol. 5, no., June 010, p Morrill W. J.: The revolving ield theory o the pitor otor. n: Trns. A, vol. 48, April 199, p

7 Journl o letril ngineering Tle The experientl results o the two onnetions T (N n trditionl (rp n new (rp P in trditionl (W P in new (W PF trditionl PF new iieny trditionl iieny new s trditionl (A s new (A trditionl (A new (A trditionl (A new (A V trditionl (V V new (V V trditionl (V V new (V