POWER CONTROLLING FOR MICRO GRID USING RENEWABLE ENERGY SOURCES

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1 POWER ONTROING FOR MIRO GRID USING RENEWABE ENERGY SOURES G. Dugapasad, D. Bud Snvasa Rao 2 Assstant.Pofesso dept. Of EEE SVET,Skakulam(Inda) 2 Asst. Pof, Dept of EEE, SVET, Skakulam(Inda) ABSTRAT Powe system plays mpotant ole fo the geneaton of powe fom onventonal soues, tansmutaton and dstbuton powe at dffeent onsume applatons t wll faes a so many poblems. Ths an be oveome to mplement the mo gd onept. The mo gd onept ntodues the powe s geneated fom the enewable enegy soues lke p.v wnd, fuel ell, mo tubne et wll gve sgnfyng moment n nea futue. these powe geneatng statons nteonneted to fom a mo gd system needed numbe of multple evese onvesatons (A-D o D-A) fo onsume applatons ths esults nease ut omplexty, ost and system have less elablty. The A/D mo gd onept ntodues to edues multple eseve onvesons and t wll onssts of both A. and D. netwoks onneted to dstbuton geneaton though multbdetonal onvetes and to mantan stable opeaton of system by usng poposed oodnaton shemes n the MATAB smulnk envonment. Keywods: mo gd, gd-ted mode, oodnaton ontol opeatons, PV system, wnd powe geneaton. I.INTRODUTION The eve neasng enegy onsumpton, the soang ost and the exhaustble natue of fossl fuel, and the wosenng global envonment have eated neased nteest n geen [enewable based enegy soues] powe geneaton systems. Wnd and sola powe geneaton ae two of the most pomsng enewable powe geneaton tehnologes. The gowth of wnd and photovolta (PV) powe geneaton systems has exeeded the most optmst estmaton. Nevetheless, beause dffeent altenatve enegy soues an omplement eah othe to some extent, multsoue hybd altenatve enegy systems (wth pope ontol) have geat potental to povde hghe qualty and moe elable powe to ustomes than a system based on a sngle esoue. Beause of ths featue, hybd enegy systems have aught woldwde eseah attenton []. Photovolta (PV) geneaton systems and solated wnd-elet systems ae onsdeed among the enewable systems to be vable altenatves fo the desgne of suh emote powe supples. Nevetheless, systems based on ethe wnd o sola enegy ae unelable due to seasonal and dunal vaatons of these esoues. The ontol of suh a sheme s also fa fom staghtfowad, espeally whee thee s a hgh wnd penetaton [2]. Futhemoe, t deeases the advantage of 4 P a g e

2 lean and no polluton enegy aheved fom the enewable soues. A system that s based fully on enewable esoues but at the same tme elable s neessay and hybd wnd and sola systems wth small battey stoage meet these equements. A hybd sheme onssts of wnd dven by nduton geneato, PV aay wth powe eleton onvetos and powe balanng ontols ae poposed n ths pape fo the pupose of edues the evesble ovet ons smooth powe vaaton between soues and mantan stable opeaton n the system. The battey bank, whh s haged dung the daytme, wll supply the nvete dung the nght to povde neessay eatve powe fo the nduton geneato. In stes whee wnds ae stongest n the wnte and spng but weake n summe when sola adaton eahes ts peak, the poposed sheme wth appopate hoe of the szes of the PV aay and wndgeneato ensues almost an unnteuptble supply thoughout the yea. II.GRID OPERATION Wheeve the bas man dagam of a A/D mo gd shows t wll onssts two enewable enegy soues one s P.V the output of P.V aay s onneted to the boost onvete. Fgue.Blok dagam of A/D mo gd A apato s supples the hgh fequeny pples of P.V output voltage.the enegy stoage battey s onneted to the D. bus though D-D boost onvete. The ated voltage of D. bus s 400v espetvely. Anothe enewable enegy deve s wnd geneaton wth DFIG s onnetng to a soues though A. bus. Thee phase bdetonal D/A man onvete wt R-- onneted between D bus and A bus. The hybd gd an opeate n two modes one s gd-ted mode and solated mode the pesent wok s dd n gd-ted mode the boost onvete and WTG ae ontolled to povde the maxmum powe. The man onvete s to povde stable d bus voltage and equed eatve powe and to exhange powe between the a and d buses. When the output powe of the d soues s geate than the d loads, the onvete ats as an nvete and njets powe fom d to a sde. When the total powe geneaton s less than the total load at the d sde, the onvete njets powe fom the a to d sde. When the total powe geneaton s geate than the total load n the hybd gd, t wll njet powe to the utlty gd. 42 P a g e

3 III. MODEING OF P.V SYSTEM Geneally, a PV module ompses of a numbe of PV ells onneted n ethe sees o paallel the lassal equaton of a PV ell desbes the elatonshp between uent and voltage of the ell (negletng the uent n the shunt esstane of the equvalent ut of the ell) as Fgue2. Equvalent ut of PV ell I ph I O Vph RseI ph I I O exp A K ov n pi ph n pi s exp ns Whee Io denotes the PV aay output uent, V s the PV output voltage, s the ell photouent that s popotonal to sola adaton, s the ells evese satuaton uent that manly depends on the tempeatue, s a onstant, n and ae the numbes of sees stngs and paallel stngs n the PV aay, espetvely. IV.MPPT (P&O METHOD) Defne Petub-and-obseve (P&O) method s domnantly used n patal PV systems fo the MPPT ontol due to ts smple mplementaton, hgh elablty, and takng effeny. Shows the flow hat of the P&O method [4-5]. The pesent powe P (k) s alulated wth the pesent values of PV voltage V (k) and uent I (k), and s ompaed wth the pevous powe P (k-). If the powe neases [6-7], keep the next voltage hange n the same deton as the pevous hange. 43 P a g e

4 44 P a g e Fgue3. Flow hat fo MPPT algothm. V.DYNAMI MODEING OF BOOST ONVERTER The man objetve of the boost onvete s to tak the maxmum powe pont of the PV aay by egulatng the sola panel temnal voltage usng the powe voltage haatest uve. Fgue 4. Boost onvete 0 ) ( ESR D V dt d Vn D n Out n.. V 0 v 0 V V 0 v R D D ESR v

5 VI.MODEING OF BATTERY Battey ats as a onstant voltage load lne on the PV aay and s haged both by PV aay and nduton geneato.the battey s modeled as a nonlnea voltage soue whose output voltage depends not only[8-9] on the uent but also on the battey state of hage(so), whh s non lnea funton of the uent and tme V V b O R b b Q K Q b dt Aexp b dt VII. MODEING OF WIND TURBINE The powe aptued by the WG blades Pm s a funton of the blade shape, the pth angle, and the adus and the oto speed of otaton. Whee ρ s the a densty (typally.25 kg/m3), β s the Pth angle (n degees), p (λ, β) s the wnd-tubne powe oeffent, R s the blade adus (n metes), and V s the wnd Speed (n m/s). The tem λ s the tp-speed ato [0]. P m P w p, P w 0.5AU 3 p 2, e 3 4 2N 60 U U VIII.MPPT AGORITHM ONERT FOR WIND ENERGY SYSTEM The algothm uses the HS methodology powe management to tak the maxmum powe ponts of wnd enegy systems unde flutuatng ondtons. The man poblems n exstng powe extaton methods ae ) ustomzaton, 2) speed, and 3) wasted powe. The poposed algothm povdes a soluton to these poblems. The poposed algothm man onept s to enable flexble, fast and effent maxmum powe extaton. The onept s t qukly detemne the maxmum powe pont by usng the tubne fundamental tp-speed ato equaton n onjunton wth the HS methodology fo eah tubne thee s one TSR that wll always n maxmum powe tansfe. 45 P a g e

6 The HS onept s essentally an obseve and petub onept used to tavese the natual powe uve of tne. In ths thess, the algothm geneates the efeene sped by measung the output powe of the wnd enegy onveson system and adjustment the system s opeatng pont aodngly. Fgue5. Flow hat fo maxmum powe pont takng fo wnd IX.MODEING OF DFIG In geneal the mahne vaables that dtate pefomane ae funtons of oto speed, load and the mahne paametes. Sne the vaous ndutanes n thee phase ae tme vayng wth oto poston [-2], efeene analyss s often used to edues the omplexty of analyss. In ase of the nduton mahne possble efeene fames ae statonay efeene fame, oto efeene fame. Usually, the mahne vaables ae fstly tansfomed to the own efame and then those ae tansfeed to equed efeene fame [3-4]. V V qs ds q ( R p ) s s qs ss qs s s ds ( R p ) m qs m ds s s p ds m q q m q m p M d m d V p ( ) ( R p ) ( ) V ( ) p ( ) ( R p ) d m qs m ds q s d d ds m d p d dt s s 2 m 46 P a g e

7 Fgue 6.Smulnk dagam of DFIG. Fgue 7. ontol blok dagam of man onvete. X.PROPOSED OORDINATION ONTRO OF THE GRID-ONNETED MODE When mo gd opeates n the gd-onneted mode, the man objetve of the HVD (a/d/a) onvete of the double-fed nduton geneato s to egulate the oto sde uent to aheve maxmum powe pont takng and boost s to tak the maxmum powe fom P.V aay by egulatng the temnal voltage and whh ae synhonze wth oespondng gd. the man onvete s desgned to opeate bdetonal to nopoate omplementay haatests of wnd and sola soues and to mantan a stable d-lnk voltage fo vaable D load and to synhonze wth the A lnk utlty system. The ole of the battey ats as a onstant voltage load lne on the PV aay and s haged both by the IG and PV aay. Unde ondtons of low wnd speed, the nduton geneato s solated fom the system and the load s fed by the PV aay and the battey. The load s fully suppled by the battey n stuatons whee thee s nadequate wnd speed and adaton [5]. Dung nghts and unde hgh wnd penetaton, the IG supples the load, the exess enegy f any beng used to hange the battey beng fully haged and unable to aept ths exess enegy 47 P a g e

8 on othe hand, dung the daytme, n the event of the battey beng dsonneted to pevent ovehagng, the IG and PV aay feed the load. In suh ondtons, the PV aay n addton to supplyng powe to the load also povdes the needed eatve powe to the IG. t should be noted that when the battey s dsonneted fom system to pevent a voltage ollapse, t s equed to opeate the PV aay as a voltage soue by load sheddng f neessay. The battey would be deeply dshaged only n the event of long duaton of both low wnd speed and adaton, and hene, s not subjeted to yl hagng and dshagng unlke n PV alone o wnd alone systems[6]. The poposed ontols ae appled to the boost onvete, man onvete, and wnd enegy system s fo the powe balanng between the A soues, D soues, and utlty gd unde vayng load ondtons.ths thess the man onvete s plays mpotant ole t wll ats as a voltage soue to poved a stable voltage and fequeny fo the gd and opeates ethe n nvete o onvete unde vayng load ondtons fo smooth powe balanng between the A lnks and D lnks. The battey onvete opeates ethe n dshagng o hagng ondton based on the powe balane n system. The powe unde vayng load and supply ondtons should be balaned as Pa + Ppv= Pb + Pd Ps=Pw-Pa-Pw XI.SIMUATION RESUTS Fgue 8. PV output voltage Fg.8.shows the output voltage of PV aay oespondng sola adaton t wll neases at to 0.3 voltage onstant usng P&O method. At the peod of 0.3 to voltage dop ou dung the load and soue ondton.the boost ontolle qukly eoves ths dop and gves onstant voltage. 48 P a g e

9 Fgue 9. PV output powe and sola adaton Fg.9. shows the output powe of PV s oespondngly neases wth sola adaton. Output powe s neases 2kw to 37kw due to hangng the tempeatue. When tempeatue s fxed at 0.2se to 0.3se powe geneaton s fxed. Fgue 0. A sde voltage and uent wave foms of the man onvete wth onstant adaton Fg.0. shows the voltage and uent of man onvete. The uent ampltude fom 0 to 0.3se s hghe than emanng tme peod means d geneaton s hghe then the d lod at the tme powe s njeted fom d to a gd befoe 0.3s and 0.4s s evesed. Fgue.. A sde voltage and uent wave foms of the man onvete wth onstant adaton and vaable load Fg.. shows the voltage and uent of man onvete. The uent ampltude fom 0 to 0.25se and 0.25 to 0.4se s dffeent tme peods means d geneaton s less than the d lod at the tme powe s njeted befoe 0.3s and 0.4s s evesed. 49 P a g e

10 Fgue2. Output powe of doubly fed nduton geneato The Fg.2. shows out powe of DFIG s losely neased fom 27kw to 30kw oespondng wnd at a peod of 0.35se to 0.5se t onstant.between the peod of 0.6se to 0.35se ous powe osllatons due hangng the wnd by usng the wnd MPPT tak maxmum powe. Fgue.3. voltage and uent wave s of the man onvete at powe balanng ondton TABE I. PARAMETERS FOR PHOTOVOTAI PANE symbol Despton Value q Rated open ut voltage Eleton hage A k Idealty fato Boltzman onstant J/K Sees esstane of a PV ell Paallel esstane of a PV Shot-ut uent Refeene tempeatue Enegy of a band gap fo slon Numbe of ells n paallel Numbe of ells n sees 3.27A 30.8 K.e V S T Sola adaton level Sufae tempeatue of the PV W/ 350K 50 P a g e

11 TABE II. PARAMETERS OF DFIG Symbol Despton Value J Nomnal Voltage Nomnal Powe Stato esstane Roto esstane Stato ndutane Roto ndutane Mutual ndutane Roto netal onstant Numbe of poles Numbe of D voltage of A/D/A onvete 50 kw 400v pu 0.7 pu pu 0.56 pu 2.9 pu 3. s V Nomnal mehanal powe 45 kw XII.ONUSION Ths pape smply povdes the altenatve enegy soluton fo dffeent onsume applatons. The desgn and developed of A/D mo gd fo powe system onfguaton s done n MATAB/SIMUINK envonment. In ths pape edues the poess of A/D and D/A onvesons n ndvdual A o D gd. Although MPPT algothm s used to haness maxmum powe fom D soue.hee poposed ontolles ae developed fo all onvete to mantan the stable system unde vaous esoue and load hangng ondtons and oodnate powe exhange powe between the D and A gd. futue wok ths pape modelng of fuel ell usng MATAB/SIMUINK envonment ths an be nteonnetng to A/D mo gd and oodnately opeate the system and mplementng n Indan mltay applatons. REFERENES []. R. H. assete, MoGds, n Po. IEEE Powe Eng. So. Wnte Meet., Jan. 2002, vol., pp [2]. Gouthamkuma N., Veena Shama, R. Naesh. "Dsupton based gavtatonal seah algothm fo shot tem hydothemal shedulng" Expet Systems wth Applatons, Vol. 42, pp , 205. [3]..Wang and M. H. Neh, Powe management of a stand-alone wnd/photovolta/fuel ell enegy system, IEEE Tans. Enegy onv., vol.23, no. 3, pp , Sep [4]. F. u, S. Duan, F. u, B. u, and Y. Kang, A vaable Step sze IN MPPT method fo PV systems, IEEE Tans. Ind Eleton., vol. 55, no. 7, pp , Jul P a g e

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