PV Based Resonant Two Inductor Boost Converter for Induction Machine Drive Application

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1 Intenational Jounal of Engineeing ends and echnology (IJE) Volue 7 Nube 5 - Septebe 05 PV Based Resonant wo Inducto Boost Convete fo Induction Machine Dive Application Paveen Sebastian, Joole Joseph Ma Baselios College of Engineeing, Electical and Electonics Engineeing Assisstant Pofesso, Electical and Electonics Engineeing, Ma Baselios College of Engineeing Keala univesity Abstact A new convete is designed to dive an induction oto diectly fo PV enegy. he developed syste is based on a cuent-fed ulti esonant convete fo achieve zeo cuent switching. It is also known as esonant two-inducto boost convete (IBC) and a thee-phase voltage souce invete. he classic topology of the IBC has featues like high voltage gain and low input cuent ipple. he topology is futhe ipoved with the use of a non isolated ecovey snubbe. he convete output is fed to a thee phase ac oto via a thee phase invete. Keywods photovoltaic powe syste, tibc convete, AC oto dives I. INRODUCION In conventional PV based dive systes boost convete and low voltage DC achine is used. Input cuent ipple in the boost convete fed dive syste is highe and DC oto have lowe efficiency and highe aintenance cost copaed with Induction achine. o avoid these pobles two inducto boost convete fed induction achine dive syste was intoduced. Input cuent ipple is less but powe egulation ange is educed[]. he two inducto boost convete exhibits benefits in high powe applications and high input cuent is split between two inductos, thus educing powe loss in both coppe windings and piay switches. Maintain powe egulation ange in the IBC convete fed induction achine dive syste an auxiliay tansfoe is intoduced. But they still have pobles with high voltage spikes ceated due to leakage inductance of the tansfoe and high voltage stess on the ectifying diodes[]. he solution to the cuent fed PWM convete is use of esonant topologies able to utilize the coponent paasitic chaacteistics such as the leakage inductance and winding capacitance of tansfoes in a poductive way to achieve the zeo cuent switching(zcs) o zeo voltage switching(cvs) condition. Modified esonant two inducto boost convete is intoduced fo PV based dive syste due to its vey sall no of coponents, siplicity, high efficiency, easy tansfoe flux balance and coon gound gating diving fo both switches[]. Input cuent is distibuted though the two boost inductos having its cuent ipple aplitude halved at twice the PWM fequency. IBC can be odified to ultiesonant convete to achieve zeo cuent condition fo the input switches and output ectifying diodes and this enables the convete to opeate at high fequency with geate efficiency. his pape intoduce a new DC-DC convete fo photovoltaic wate puping systes. he aangeent will be in the fo section II gives detailed desciption about sola syste III gives detailed desciption about poposed syste, detailed woking of convete is pesented in section IV contol pat in section V; siulation esults in section VI II.SOAR SYSEM A sola cell is the building block of a sola panel. A photovoltaic odule is foed by connecting any sola cells in seies and paallel. Consideing only a single sola cell; it can be odeled by utilizing a cuent souce, a diode and two esistos[4]. his odel is known as single diode odel of sola cell. wo diode odels ae also available but only single diode odel is consideed hee ig : Single diode odel of a sola cell he chaacteistic equation fo a photovoltaic cell is Whee, Io I given by Iph= Isc+ Ki (-8)*ƛ 000 Is=Isc ([exp(qvoc/(ns ka))-]) s [ ] Ego exp[ q* ]{ Bk Ipv=Np*Ipv-Np*Io[exp {(q*(vpv+ipvrs Ak)}-] I & V : Cell output voltage and cuent Ios : Cell evese satuation cuent : Cell tepeatue in celsius k : Boltzann's constant,.8 * 0 - J/K; }] ))/(Ns ISSN: Page 54

2 Intenational Jounal of Engineeing ends and echnology (IJE) Volue 7 Nube 5 - Septebe 05 q : Electon chage,.6*0 - C; Ki : Shot cicuit cuent tepeatue coefficient at Isc; Isc : Shot cicuit cuent at 5 degee Celsius; Ilg : ight-geneated cuent; Ego : Band gap fo silicon; A : Ideality facto; :Refeence tepeatue; Io : Cell satuation cuent ; Rsh : Shunt esistance; Rs : Seies esistance; he chaacteistic equation of a sola odule is dependent on the nube of cells in paallel and nube of cells in seies[4]. It is obseved fo expeiental esults that the cuent vaiation is less dependent on the shunt esistance and is oe dependent on the seies esistance. PV odule odels ae ipleented as asked subsystes in Siulink. Inputs ae PV cuent and insolation and outputs ae PV voltage and PV powe. Matlab M-file poga witten inside atlab function to obtain PV cuent as output with voltage, iadiation and tepeatue as inputs. able.electical chaacteistics data of sola. KW PV odule Rated Powe.KW Voltage at axiu powe III. PROPOSED CONVERER 87V Cuent at axiu powe 5.04A Open cicuit voltage 88.V Shot cicuit cuent.5 A otal no of cells in seies 0 otal no cells in paallel 8 Cell voltage(seies) 8.8V Cell voltage(paallel).74v Poposed convete is designed fo highe efficiency application. Its advantages ae high life tie, low cost and easy accessibility. his convete design focused on single stage PV odule. ig. shows the basic block diaga of the syste. he enegy fo PV panel fed to induction oto by two siple powe stages. he IBC convete used hee fo boost the voltage fo the PV panel and hee phase invete convet the DC voltage fo the convete to phase AC voltage. he two inducto boost convete equies lage voltage convesion atio because of low input cuent ipple and low voltage natue of photovoltaic panels. he coonly use voltage fed convete have high input cuent ipple so filte capacito needed[5]. ilte capacitos ae electolytic so it will affects the life tie of the convete Cuent fed convetes have soe advantages they ae it have high step-up voltage atio and educes tansfoe tuns atio but its disadvantages ae high voltage stess due to leakage inductance of tansfoes and high high voltage stess on ectifying diodes. his disadvantages can be ovecoe by the use of esonant topology. hee fo the convete will odified as esonant convete. he coponent paasitic paaete like the leakage inductance and winding capacitance of tansfoe in a fuit full way to achieve zeo cuent switching(zcs) o zeo voltage switching(zvs)[6]. ig: siplified block diaga of wate puping syste ig. shows the odified tibc topology. he ain pats ae esonant tank cicuit, voltage double ectifie and snubbe cicuit. Resonant tank cicuit is fo achieving zeo cuent switching o zeo voltage switching. By eploying a voltage double ectifie at the seconday teinal of the tansfoe as in fig.(b), it is possible to educe voltage stess on the MOSEs to half of the oginal ones, tansfoe tuns atio as well as necessay feite coe can be educed. inally as a esult the tansfoes and MOSEs can be ade cheape and the no of diodes in the seconday sides can be halved. Classically, the IBC have a iniu opeation load to aintain an established output voltage. Below a cetain load level, the enegy tansfeed to the output capacito is not copletely tansfeed to the load and causes an incease in the output voltage[]. his happens because the inductos ae chaged even if thee is no output cuent. As a esult, this convete has a dawback when used in oto dive systes. Since the oto is a vaiable load and it has lage tie constants, it will deand low powe at soe opeation points. As a solution non dissipative egeneative snubbe cicuit is pesented shown in fig (c).. ISSN: Page 55

Intenational Jounal of Engineeing ends and echnology (IJE) Volue 7 Nube 5 - Septebe 05 ig. Modified IBC topology: (a) esonant tank (b) voltage double ectifie (c) snubbe IV.

3 Intenational Jounal of Engineeing ends and echnology (IJE) Volue 7 Nube 5 - Septebe 05 ig. Modified IBC topology: (a) esonant tank (b) voltage double ectifie (c) snubbe IV. OPERAION PRINCIPE wo Inducto boost convete have six opeating odes. he theoetical wave fos of these opeating odes ae illustated in fig.4. At tie t, the ectifying diode Do is aleady conducting, and the voltage on esonant capacito C is claped at +V out/. At this instant, the switch Q is activated by VgQ. As the switch is tuned ON, its voltage dops to zeo, and the snubbe diode Ds is foced to stop conducting. o t to t, C tansfes its enegy to the leakage inductance, beginning the piay switch s esonant pocess and focing the cuent IQ on the switch Q to decease. decease until it eveses its polaity. When IQ is negative, the switch can be tuned off. his happens at instant t when VgQ is foced to zeo. At the tie t, the voltage VdsQ stats to incease, Q is copletely blocked, and the snubbe diode Ds begins to conduct, tansfeing enegy diectly to the snubbe capacito Cs. Between t and t4, C and continue to esonate, deceasing the voltage on the double ectifie s input and on VC. At instant t4, the voltage acoss C eaches Vout/, and the ectifying diode Do stats to conduct, claping VC in Vout/. o t4 to t5, the capacito Co is chaged, and the cuent Of Do stats to decease. At the instant t5, Q is tuned on, initiating the esonant pocess on Q. As Q is activated, Ds is foced to stop conduction. At the instant t6, the cuent in Do eaches zeo, and Do stops conducting, einitiating the esonance between C and. o this oent, until the end of the switching peiod, the pocess epeats syetically as explained fo the othe input switch. A siplified ethodology based on the effect of each esonant pocess, the esonant fequencies, and the switching fequency is applied. Matlab siulations and a pototype is used to show that, despite the siplicity of the design ethodology, the coect opeation of the convete is guaanteed, paticulaly the soft switching of the piay switches fo the whole opeating load ange. Although the esonant pocess affects the output voltage, depending on the esonant tank coponent values and the load, this can be neglected because of its sall influence and coplex effect. Although the esonant pocess affects the output voltage, depending on the esonant tank coponent values and the load, this can be neglected because of its sall influence and coplex effect. hus, neglecting the esonant effect ove the output voltage, including the voltage double ectifie and the snubbe connecting the piay and the seconday side of the convete[]. V.SYSEM DESIGN he static voltage gain (Kv) of the convete is defined as V V out in K v N ( D N s p ) ig.4 key wave fos of the tibc duing switching peiod o t to t, the piay switch s esonance (Q) continues to foce its cuent to whee D epesents the duty cycle of each switch and ust be highe than 50% to guaantee the necessay ovelapping fo the coect opeation. Ns/Np epesents the tansfoe tuns atio. o iniize the influence of the load on the esonant pocess on the piay cuent coutation inteval, the switching fequency (sw) should be highe than ISSN: Page 56

4 Intenational Jounal of Engineeing ends and echnology (IJE) Volue 7 Nube 5 - Septebe 05 the esonant fequency (s) of and C by a value of at least.. hus, s C sw. Duing the piay cuent coutation inteval, when both switches Q and Q ae tuned on, inducto paticipates on the esonance in paallel with and C; thus, the esonant fequency fo this inteval is defined as p C Consideing that epesents the agnetizing inductance and epesents the leakage inductance, then is uch lage than ; thus, can be siplified to p C he duation of the coutation inteval is equal to the ovelapping tie (ov) of the pulse diving signals and can be calculated as he whole esonant pocess of the piay switches has the duation of half a esonant cycle, as shown in ig. 4. o guaantee the ZCS condition fo the entie load ange, the following conditions ust be satisfied: ON ON p ( D 0.5) D SW sw Anothe ipotant constaint is the enegy accuulated in C at the beginning of the piay switching esonant pocess. his enegy needs to be copletely tansfeed to the leakage inductance duing this pocess. o this condition, the following equation is deived: RESONAN ANK CIRCUI DESIGN p C (D ) 0 s ( C ) C C sw sw 80 0 / VO V0 in I C ISSN: Page 57

5 Intenational Jounal of Engineeing ends and echnology (IJE) Volue 7 Nube 5 - Septebe 05 he bus voltage which is defined using the iniu necessay voltage fo the invete topology and PWM stategy. wo inducto boost convete switching fequency ust be copoised between the switching losses and the inducto as well as tansfoe size. Switching fequency is usually designed to be 80 KHZ, which is used in siulation. Duing fixed duty cycle contol in ode to guaantee ovelapping conduction of MOSEs, D is chosen to be 5% based on the iniu equied ovelapping and coutation ties of the MOS and the dives selected VI.SIMUAION RESUS he siulink odel of PV based two inducto boost convete connected to induction oto is shown below able. Convete paaetes Paaetes Values Inductance i, i, i 00µH Capacitance C 0,C 0,C 0 C Switching fequency.5µ n.7h 0.85H 80kHZ he output of two inducto boost convete settles at 45V. he siulation esult of output of the convete is shown below. Siulation esult of input of the DC to DC convete. ig 7 shows the output voltage of the DC- DC convete. ig 5. Siulink odel of PV based IBC connected to induction oto ig 6 shows the gate voltages of two switches. Duing fixed duty cycle contol in ode to guaantee the ovelapping conduction of MOSEs, D is chosen to be 5% based on the iniu equied ovelapping and coutation ties of the MOSE and the dives selected. ig.7 output of the DC to DC convete ig 8 shows the siulation esult of zeo cuent switching. o the siulation esult it is clea that both tun on and tun off occus at zeo cuent switching. ig.6 Gate voltage wavefos ig.8 Veification of zeo cuent condition on the input switch Q ISSN: Page 58

Intenational Jounal of Engineeing ends and echnology (IJE) Volue 7 Nube 5 - Septebe 05 As can be seen, fo an input DC voltage of 45V, the cicuit poduces phase ac voltage

he filteed output voltage wavefos of invete ae shown below in fig 0. ig Output line voltage wavefos fo phase PWM invete with achine load able.

0 ilteed output voltage of invete ig. shows thee phase cuent,toque and speed of the achine. he achine acceleates and coe to steady state at 0.

coplete dq odel of induction he inputs of a Induction achine ae the thee-phase voltages, thei fundaental fequency and the load toque.

6 Intenational Jounal of Engineeing ends and echnology (IJE) Volue 7 Nube 5 - Septebe 05 As can be seen, fo an input DC voltage of 45V, the cicuit poduces phase ac voltage output (fig.).he output voltages of thee phases ae 0 degee apat fo one anothe. hus invete action was obtained. he filteed output voltage wavefos of invete ae shown below in fig 0. ig Output line voltage wavefos fo phase PWM invete with achine load able. Machine paaetes PARAMEERS VAUES R.805 Rs 4.85 ls l fb 50 p 4 J 0.0 l+ /R wb *pi*fb Xls wb*ls Xl wb*l X wb* Xsta /(/Xls+/X+/Xl). ig.0 ilteed output voltage of invete ig. shows thee phase cuent,toque and speed of the achine. he achine acceleates and coe to steady state at 0.5 sec with a sall slip because of inetia load. he achine is siulated by applying 45V thee phase ac voltage at 50 Hz With just inetia (=0). achine ig. coplete dq odel of induction he inputs of a Induction achine ae the thee-phase voltages, thei fundaental fequency and the load toque. On the othe hand the outputs ae the thee-phase cuents, the electical toque and the oto speed. he achine paaetes of Hp induction achine is used fo siulation. ig. hee phase cuents,toque and speed of induction achine When = 0 N, at steady state e appoaches, oto speed educes due to loading with ὡe = ad/sec and ὡ = ad/sec shown in ig. ISSN: Page 5

7 Intenational Jounal of Engineeing ends and echnology (IJE) Volue 7 Nube 5 - Septebe 05 ig. he stato cuent of the induction oto at ated speed VII.CONCUSION Softwae odel of PV based two inducto boost convete fed induction achine dive is done and concluded that the DC output obtained was vey high in PV based IBC fed induction achine dive copae with conventional topology. Switching losses ae eliinated by achieving zeo cuent switching(zcc). [] R.-Y. Chen,.-J.iang, J.-.Chen, R.-.in, and K.-C. seng, Study and ipleentation of a cuent-fed full-bidge boost dc-dc convete withzeo-cuent switching fo high-voltage applications, IEEE ans. Ind.Appl., vol. 44, no. 4, pp. 8 6, Jul./Aug [4J. Ki, H.-S.Song, and K. Na, Asyetic duty contol of a dualhalf- bidge dc/dc convete fo sing] le-phase distibuted geneatos, IEEEans. Powe Electon., vol. 6, no., pp. 7 8, Ma. 0. [5] B. iu, C. iang, and S. Duan, Design consideations and topology selection fo dc-odule-based building integated photovoltaic syste, in Poc. d IEEE Conf. ICIEA, Jun. 5, 008, pp [6] J. Biela and J. W. Kola, Using tansfoe paasitics fo esonant convetes A eview of the calculation of the stay capacitance of tansfoes, in Conf. Rec. 40th IEEE IAS Annu. Meeting, 005, pp [7]. Yan and B. ehan, Isolated two-inducto boost convete with one agnetic coe, in Poc. IEEE Appl. Powe Electon. Conf. Expo., 00,pp [8] Y. Jang, wo-boost convete, U.S. Patent 6 584, May, 00. [] Q. i and P. Wolfs, he powe loss optiization of a cuent fed ZVS two-inducto boost convete with a esonant tansition gate dive, IEEEans. Powe Electonics, vol., pp. 5 6, Sep [0] B. Ozpineci and. olbet, Siulink ipleentation of Induction achine odel, IEEEans. Powe Electonics,vol.4, pp. 6-6, feb.0 REERENCES []J. victo, G. aias,.eizeia,. Ribeio, Ipleentation of high efficiency, High-life tie, and low cost convete o an autonoous photovoltaic wate puping syste, IEEE ans. Ind. Applications, vol. 50, no.,pp. 6-67,feb. 04 [] United state patents Jang et. Al. patent no US 6,,584B [] D. schanz, H. ovatt, A. Vezzini, and V. Peenoud, Single phase thee level boost powe facto coection convete, in Poc. IEEEAPEC, Poc, pp. 44 4,5 [4] N. Pandiajan, R. RanganathMuthu Matheatical odelling of photovoltaic odule with siulink, ICEES,pp.-5,jan 0 [5] M. A. Vitoino, M. B. R. Coea, C. B. Jacobina, and A. M. N. ia, An effective induction oto contol fo photovoltaic puping, IEEE ans.ind. Electon., vol. 58, no. 4, pp. 6 70, Ap. 0. [6] S. R. Bowes and A. Midoun, Suboptial switching stategies fo icopocesso contolled PWM invete dives, Poc. Inst. Elect. Eng. Elect.Powe Appl., vol., no., pp. 48, May 85. [7] M. Cacciato, A. Consoli, and V. Cisafulli, A high voltage gain dc/dc convete fo enegy havesting in single odule photovoltaic applications, in Poc. IEEE ISIE, 00, pp [8] P. J. Wolfs, A cuent-souced dc-dc convete deived via the duality pinciple fo the half-bidge convete, IEEE ans. Ind. Electon., vol. 40, no., pp. 44, eb.. [] P. Wolfs and Q. i, An analysis of a esonant half bidge dual convete opeating in continuous and discontinuous odes, in Poc. IEEE PoweElecton. Spec. Conf., 00, pp. 8. [0] W. i,. an, Y. Zhao, X. He, D. Xu, and B. Wu, High stepup and high efficiency fuel cell powe geneation syste with active clap flybackfowad convete, IEEE ans. Ind. Electon., vol. 5, no., pp. 5 60, Jan. 0. [].-J. iang, R.-Y.Chen, J.-.Chen, and W.-J. zeng, Bucktype cuentfed push-pull convete with ZCS fo high voltage applications, in Poc.IEEE Region 0 Conf., 007, pp. 4. [] P. M. Babosa and I. Babi, A new cuent-fed, isolated PWM dc-dc convete, IEEE ans. Powe Electon., vol., no., pp. 4 48, May 6. ISSN: Page 60

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