Int ern at i onal  Journ al of  P ower E le ctr on i cs a n d  Drive  S ystem s   ( IJ PEDS )   Vo l.   12 ,  No.   2 ,  Jun  2021 ,  pp.  11 5 0 - 116 1   IS S N:  20 88 - 8694 ,  DOI: 10 .11 591/ ij peds . v12.i 2 . pp 11 5 0 - 116 1       1150       Journ al h om e page :  http: // ij pe ds .i aescore.c om   Des i gn   and   co ntr ol   of   gr i d - connec ted   s olar - wind   i nte grated   conversi on   s yste m   with   DFIG   s upplyi ng   t hree - phase   f our - wire   loads       Arj u n   K um ar   GB,   Shiv as h ankar ,   Ke sh avamu r th y   Depa rtment   of   E le c troni cs   &   Co mm unicati o n   En gine er ing,   Sri   V enka t eshwara   C oll eg e   of   Engi n e eri ng,   Beng al uru ,   Indi a       Art ic le   In f o     ABSTR A CT   Art ic le   hist or y:   Re cei ved   J ul   26 ,   20 20   Re vised   M a r   2 6 ,   20 21   Accepte d   Apr   18 ,   2021       Thi s   p ape r   desc ribe s   the   ar chi t e ct ure   and   cont ro l   of   an   aut onom ous   hybri d   solar - wind   sys te m   (AH SWS)   powere d   dist ribut ed   g ene r ation   sys tem   supplying   to   a   3ϕ - 4   wire   sys te m .   It   includes   a   no nli ne ar   cont rol ling   techniqu e   for   ma xi mum   p ower   point   trac king   (MP PT)   used   in   doub ly   fe d   induc t ion   gene ra tor   dep en dent   wind   en erg y   tra nsla ti on   sch em e   and   solar   p hotovol taic   sys te m   (SP VS ).   In   th e   hybrid   m odel ,   the   DC/D C   conv erter   out put   fro m   the   PV   sys te m   is   expl ic i tl y   coupl e d   with   the   DC - l ink   of   DF IG's   b ac k - to - b ac k   conve rt er.   An   ar it hmetical   model   of   th e   d evi c e   is   deve lop ed,   der iv ed   using   a   suita ble   d - q   r eferenc e   fra me .   Th e   grid - vo lt ag e - o rie nt ed   ve ct or   re gula ti on   is   req uire d   to   m an age   th e   GSC   to   kee p   th e   ste ady - stat e   vo lt ag e   of   the   DC   bus   and   to   ad just   r ea c ti ve   pow er   on   the   grid   sid e.   Also,   the   st a tor - voltage - orie nt ed   con trol   sche me   of fer s   a   stabl e   fun ct ion   of   DF IG   to   reg ulate   th e   RS C   on   the   st at or   e dge   for   re activ e   and   active   p ower   m ana g ement   in   thi s   appr oac h .   DC/D C   conve r te r   is   b ei ng   used   to   mainta in   th e   m aximum   power   from   SPVS.   A   Perturb   &   Obs e rve   m et hod   is   used   for   tracin g   ma x im um   power   in   an   SP VS .   The   simul ation   designs   of   4. 0kW   DF IG   and   4. 5kW   sola r   arr ay   simu lator   are   bui lt - in   SIM PO WE R   software   kit   of   MA TL AB,   it   is   show n   to   ac h i eve   optimum   eff icienc y   und e r   var ious   me c hani c al   and   el e ct ri ca l   ci rcu m stanc es.   It   can   p roduc e   rated   fre quenc y   and   voltage   in   both   sce nar ios.   Ke yw or d s :   Dou bly - fe d   in duct ion   ge ne rator   So la r   ph otovo l ta ic   sy ste m   Sensorless   ma ximum   powe r   po i nt   trac king   Gr i d   side   co nv erter   Rotor   Side   co nverter   This   is   an   open   acc ess   arti cl e   un der   the   CC   BY - SA   l ic ense .     Corres pond in g   Aut h or :   Ar j un   K um a r   GB     Dep a rtme nt   of   Ele ct ro nics   &   Comm unic at ion   E ngineeri ng   Sr i   V en katesh war a   Coll ege   of   E ng i neer i ng   Be ng al uru,   Ka rn at a ka,   India     Emai l:   arju ngb@g mail .c o m       1.   INTROD U CTION   The   gl ob al   pr oble ms   of   the   21 st   ce ntury   i nclud e   cl imat e   c ha ng e ,   ene rgy   c os ts,   an d   growi ng   en er gy   dema nd.   T his   can   be   a ddress ed   in   pa rt   by   a dd i ng   ef fici ent,   distri bu te d,   a nd   re newable   energ y   re sourc es.   B ut   stren gth e ning   performa nce   in   al l   aspects   of   ren e wa ble   e ne rgy   ge nerat io n   is   of te n   a   m aj or   issue .   Thi s   has   a   direct   or   i nd i re ct   impact   on   t he   su sta i nab le   dev el opment   of   t he   ene rgy   prov i der s   in   c onte xts   of   e ne rgy   costs   and   gen e rato r   dura bili ty.   T he   great er   the   pe rformance ,   t he   re du c ed   the   losses,   an d   th us   t he   li feti me   of   a   gen e rato r   is   sign i ficantl y   higher   co mp a re d   to   tra diti on al   s ys te ms.   In   t he   cu rr e nt   global   co ntext   near l y   tota l   instal le d   ca pac it y   reac hing   597   GW   in   2019   [1],   an d   the   DF I G   de rive d   wind   e nerg y   ge ner at io n   de vi ce   is   a   pr e valent   c hoic e   base d   on   te chn ic al   a vaila bili ty   an d   c ontrol   feasibil it y.   Althou gh,   the   DF I G's   ef fici ency   is   sti ll   a   con ce rn.   Simi la r   wi nd   e nerg y   s ys te ms   base d   on   D FIG   ha ve   dev el ope d   ov e r   t he   past   couple   of   deca des.   Evaluation Warning : The document was created with Spire.PDF for Python.
In t J  P ow Elec   & Dri S ys t   IS S N: 20 88 - 8 694       Desig n a nd control  of  gr id - c onnected  s ola r - wi nd integ ra te d  c on ve rsio n  s yst em  …   ( Arju n  K umar GB )   1151   At   fi rst,   DFI G - centere d   wi nd   ene r gy   co nve rsion   sc he mes   with   se nsor - le ss,   gr i d   c onne ct ion s   we re   su ggest e d   [2 ] - [ 6].   In   [7]   s ugge ste d   var io us   s cheme   will   co ns ide r   the   ef fe ct ive   opti miza ti on   a ppr oac h   to   s olv e   micro - gri d   opti miza ti on   iss ue s   with   li mit at ion s.   In   [ 8],   po w er   qual it y   in   t he   el ect ric   gr i d   and   to   inte gr at e   wind   el ect rici ty   pro duct ion   util iz ing   Stoc kwel l's   tr ansfo rm   (S T )   thr ough ou t   dif f eren t   operati ng   cases.   Like wi se,   in   the   ea rlie r   ph a s e,   sta nd al on e   DF I G   off - gr id   sy ste ms   ha ve   be en   s ugge ste d   as   outl ine d   [9 ] - [ 12]   for   is olate d   a rea   el ect rificat ion .   It   was   f ound   that   ge ner at or   pe rformanc e   an d   power   su ppl y   inter missi on   are   t he   main   chall enges   in   these   sug gested   met hods .   T he se   c on ce r ns   al so   nee d   to   be   pro per ly   discu ssed   f or   s us ta i nab l e   wind   powe r   te chnolo gy   de ve lop me nt   giv e n   eff ic ie ncy   an d   e nerg y   c os ts   [ 13].   Co ncern ing   DFI G   e ff i ci ency ,   init ia ti ves   have   bee n   create d   to   re gula te   the   de vice   thr ou gh   wea ke ning   the   D FIG's   flu x   le vel,   as   pr e sented   [14 ] ,   [ 15].   B ut   the   low   to rque   an d   ma gne ti c   sat ur at ion   of   bo t h   the   hig h   velocit y   a nd   the   low - vel ocity   op e rati onal   a re as   re stric t   thei r   us e   for   a   la r ge   ra ng e   of   s pe eds.   [ 16]   A   double   VSI - DFIG   with   DC   outp ut   util iz ing   a   r ot or   cu rr e nt - ori ented   sta tor   f r equ e nc y   c ontr ol   sc heme   wa s   s uggested   to   a void   the   a bove - mentio ned   s pe ed   li mit at ion s.   Th rou ghout   this   meth od   of   con t ro l,   t he   frequ e nc y   of   sta tor   is   not   va riable   as   reg a rds   ef fici ency.   E ff ect ive   co ntro l   mode ls   hav e   bee n   dev el op e d   to   i ncr ease   the   pe rformance   of   DF I G   dep e ndent   WE GS   in   [17 ] - [ 19 ].   S uc h   a rr a nge ments   do   not   t ake   int o   acc ou nt   the   c oppe r   l os ses   of   the   m achine,   al tho ug h   it   is   a   si gn i ficant   loss   fact or.   The   ne xt   pro blem   c oncer ni ng   the   WE G S   is   t he   e xist ence   of   inter mit te nt   w ind   powe r   s yst ems.   T he   pr e vious   c oncer ns   can   be   ad dr essed   a ppr opri at el y   by   wind   an d   photov oltai c   hybri d   s ys te ms   with   batte r y   ba ckup,   as   na tu rall y   wind   an d   so la r   PV   generati on s   c ompleme nt   each   oth e r   [ 20]. O n   this   ba sis,   a   hy br i d   wind   a nd   so la r - PV   ge ner at io n   model   has   bee n   pro posed   in   [21].T he   DC - link   volt age   c ontr oller   an d   pe rfo rm ance   of   DFI G   were   t he   biggest   c halle ng e s   in   t his   con t ro l   config ur at io n,   restrict ing   its   impleme ntati on s   f or   micr ogr ids   dominate d   by   re ne wab le   ene r gies   a nd   la r ge   sp ee d   se rv ic e   r especti vely .   The   fun dame nt al   ben e fit   of   the   DF I G - SP V S   hy br id   m od e l   is   to   minimi z e   the   pr ic e   of   conve ntion al   structu res.   T he   low - c os t   mod el   in   renewa bl e   ene r gy   ma rket s,   pa rtic ularl y   in   rural   a reas ,   is   quit e   co mpe ti ti ve.   To   furthe r   min imi ze   costs,   a   sens or - le ss   ma ximum   point   tr ackin g   te c hn i que   (MPPT )   for   both   the   PV   s ource   and   hybri d   de vi ce   is   pro po se d.   T he   ke y   idea   of   this   te ch niq ue   is   to   util iz ing   outp ut   po wer   to   cal culat e   in pu t   powe r.   T he   gri d   side   co nver te r   ( GS C)   an d   ro t or   side   c onve rter   (RSC)   powe r   ca n   be   us e d   in   ope ra ti on   to   cal culat e   the   S PV S   po wer   a c cordin g   to   the   DC - link   balanc e   of   the   hy br id   model.   The   fo ll ow i ng   sect ion s   desc ri be   a   detai le d   e sti mate   al gorithm.   S uch   a   se ns or - le ss   M PP T   te ch nique   has   bee n   i mp le mente d   a nd   e ffec ti vely   im ple mented   to   an   a utonomo us   PV   de vice   in   our   pr e vious   w ork   [22].   This   strat e gy   will   reduce   t he   costs   in   c omp ariso n   with   the   hybri d   m od el   us in g   a   co nven ti on al   M PPT   model.   The   pr ic e   of   t he   hybri d   mod el   is   substanti a ll y   chea per   wit h   the   use   of   le ss   po wer   el ect ronic   c onver te rs   a nd   le ss   ap propriat e   sens ors.   In   the   low   volt age   ride - th rou gh   s ources   mu st   be   en han ce d   to   com pensat e   for   the   changin g   vo lt a ge   withi n   t he   gri d   duri ng   a   fa ult   [ 23] .   MAT LAB/Si mu li nk   is   us e d   to   devel op   a nd   e valu at e   the   com plete   sy ste m.   This   a rtic le   introd uces   an   a utonomo us   hybr i d   so la r - wind   sy ste m   ( A HSWS )   sy ste m   ut il iz ing   a   WES - DFI G   and   S PVS   wit h   3ϕ,   4 - li ne   ba tt ery   e ne rgy   st or a ge   s upply   gri d.   T he   se ns or - le ss   M PPT   hybri d   model   can   e xe cute   well   with   changes   in   at mo s pheric   ci rc um sta nces   an d   con t ro l   c onditi on s ,   as   can   be   seen   with   sim ulati on   re su lt s.   Th re e   co nv e rters   can   work   sm oo t hly   a nd   in   coll aborati on,   w hile   the   DF I G   m od e   of   op e rati on   dif f ers   both   in   a bove   a nd   bel ow   rated   s ync hro nous   s pee d.   Also,   the   ba ck - to - back   c onve rter   mana ges   t he   S PV S   DC   po we r   a nd   mai ntain s   the   DC - li nk   balance d   e ve n   with out   an   in ver te r .   Finall y,   it   is   con cl ud e d   that   in   al l   so rts   of   op e rati ng   ci rc um sta nces   the   com plete   modu le   ca n   pro vi de   rate d   volt age   an d   fr e qu e nc y,   ma int ai nin g   DFI G   cu rr e nt   sta bl e   and   t he   inte gr at e d   sen sor - l ess   de vice   can   be   an   ef fecti ve   and   reli able   so l utio n   for   diff e re nt   SPVS   a nd   D FIG   set up s .   The   ke y   ob je ct ive   of   t his   arti c le   is   dem onstra ti ng     •   To   desig n   an   auto nomous   hybri d   s olar - wi nd   s ys te m   (AHS WS)   sy ste m   util iz ing   a   WES - D FIG   an d   SPVS   with   3ϕ ,   4 - li ne   batte ry   energ y   sto ra ge   su ppl y   gr id   •   To   im pleme ntati on   of   a   s ens or - le ss   wi nd   S peed   c ontr ol   sche me   de pende nt   on   Ad a ptive   Ba ckstep ping.   •   To   ac hieve   opt imum   e ff ic ie nc y   unde r   var io us   mec han ic al ,   e le ct ri cal   ci rcumst ances       2.   STUDIE D   M ODEL   AND   DESIG N   COMPO NENT S   The   aut onomo us   hy br id   s olar - wi nd   s ys te m   ( AHSW S)   m od el   util iz ing   a   WES - D FIG   an d   SP VS   wit h   3ϕ ,   4 - li ne   batt ery   e nergy   st orage   s upply   gri d   is   i nvest igate d   in   t his   st udy   a nd   is   re pr e s ented   in   Fig ur e   1.   In   this   co nfi gurat ion ,   the   DC - DC   co nv e rter   outp ut   is   c onne ct ed   to   the   ba ck - to - back   DC - li nk   co nverte r .   An   inv e rter   of   t he   SP VS   is   t hen   rem ov e d.   T his   will   mi nimize   the   co sts   of   t he   overall   de vice.   In   this   stu dy,   the   chop per   c on ve rter   is   B uck - B oo st   (в - в ),   it   ha s   a   ve r y   ste ad y   f unct io ning   and   quic k   reac ti on   a nd   it   mainta ins   the   maxim al   ge ner at io n   of   powe r   f rom   SP VS .   T he   m axi mal   powe r   is   pro vid e d   to   the   DC - link   volt age.   T he   DC   po wer   ca n   then   be   c onve r te d   into   AC   po wer   by   RSC   a nd   GS C,   w hich   is   supp li ed   to   t he   r otor   or   gri d.   The   Evaluation Warning : The document was created with Spire.PDF for Python.
            IS S N :   2088 - 8 694   In t J   P ow  Ele c  &  D ri   S ys t,   V ol .  12 , N o.   2 ,  J une  2021   :   11 5 0   –   116 1   1152   sy nc hro nizat io n   of   these   c onve rters   to   m anag e   powe r   flo w   is   exami ned   a nd   detai le d   in   the   sim ulati on   analysis.   A   s e ns or - le ss   c ontr ol   sc heme   for   the   hybri d   m odel   is   de velo pe d.   T his   a ppr oa ch   will   dec re ase   the   numb e r   of   SP VS   se nsor s,   t he reby   minimi zi ng   the   c os t   of   the   hybri d   mod el           Figure   1 .   Re pr esentat ion   of   t he   a utonomo us   hybri d   so la r - w ind   sy ste m   ( A HSWS)   wit h   a   batte ry   ene r gy   sy ste m.       The   A HSWS   is   dev el op e d   for   a   distrib uted   gen e rati on   sch eme   with   a   ma ximal   load   requireme nt   of   4KW   an d   a   m ean   l oad   of   2KW   for   a   fe w   house holds .   T he   19%   capaci ty   util iz at ion   fact or   is   deeme d   f or   the   so la r   an d   wi nd   syst em   blo c ks.   T he   maxi mum   rate d   c apaci ty   of   s olar   pa ne ls   ( _   )   a nd   wind   tur bin es   ( _   )   is   c on si der e d   as   4KW .   T he   entire   s ys te m   co ntains   two   vo lt age   c onve r te rs:   the   RSC   and   the   GS C,   wh ic h   ar e   at ta ched   bac k - to - back   at   the   DC   en d   as   s how n   in   Fig ur e   1.   T he   RSC   and   GS C   AC   end s   a r e   at ta ched   to   the   ro to r   wi nd i ngs   and   t he   loa d   ports,   c orrespo nd i ng l y.   RSC   regulat es   the   wind   tur bin e   s peed   to   ob ta in   the   wind   M PP T.   T he   so la r   po wer   s upplied   to   the   DC   bus   via   the   DC - DC   bo os t   c onver te r   is   al so   config ur e d   with   the   s olar   M P PT.   GS C   s uppl ie s   rate d   fr e qu ency   an d   volt ages   at   t he   po i nt   of   the   co mm on   li nk.       3.   DFIG   AND   S PVS   M ODEL ING   DF I G   an d   SP VS   a rithmeti c   eq uatio ns   a re   ad dr es sed   in   this   par t.   S uc h   m odel s   a re   extre mely   importa nt   to   e va luate   DFI G   a nd   SP VS   f un ct ion s   an d   c ontr olli ng   strat egie s.     3.1.   SPV S   M odel   An   ide ntica l   S PV   m odule   ci r cuit   is   pr ese nte d   in   Fig ur e   2.   This   mod ule   is   in vo l ved   in   the   di od e   a nd   current   source   co nn ect e d   to   par al le l.   T he   outp ut   resist or   and   the   diode   pr ima rily   e val uate   the   SP V   modu le   char act e risti cs.   T he   a rithmeti c   eq uatio n   ass o ci at ion   am on g   SP VS   an d   volt age - c urre nt   cou l d   be   de scr ibed   as   (1)      = − [  ( ∗  + ∗ ∗ ∗ ∗ ) − 1 ]   (1)     wh e re,      an d      ar e   SP VS   vo lt a ge   an d   c urren t   c orres pondin gly,   - sat ur at io n   c urre nt   of   diode,   q - c harge   of   an   el ect ron,   A - diode   mate rial   factor,   K - B oltzma nn   c on sta nt ,   T - a bs ol ute   te mp e rature,   a nd   - series   resist or.   The   cha racteri sti c   of   the   SPV   s ys te m   is   hi gh ly   a ff ect ed   by   en vir onm ental   fact or s   s uch   as   ra diati on   a nd   te mp erat ur e .   An   MPPT   te c hniqu e   is   th us   es sentia l   to   main ta in   the   maxi mal   powe r   out pu t   of   the   SP V   unit .   Re pr ese ntati ve    - c urves   of   SP VS   is   sho wn   in   Fig ur e   3.     Evaluation Warning : The document was created with Spire.PDF for Python.
In t J  P ow Elec   & Dri S ys t   IS S N: 20 88 - 8 694       Desig n a nd control  of  gr id - c onnected  s ola r - wi nd integ ra te d  c on ve rsio n  s yst em  …   ( Arju n  K umar GB )   1153       Figure   2 .   PV   E qu i valent   ci rc ui t           Figure   3 .    - curv es   of   PV       3.2.   DFIG   m od el   In   se ver al   res earch   stu dies,   D FIG - WTs   are   s ugge ste d   an d   est ablis he d.   T he   DFI G   model   an d   impleme ntati on   a re   desc ribe d   in   detai l.   This   researc h   arti cl e   disc us ses   on l y   ba sic   work - rel at ed   e quat ion s .   T he   relat ion   betwee n   the   sta tor   fl ux   a nd   cu rr e nt   t he   occurs   in   the   sta tor - flu x   c ompa rison   fr am ewor k   is,      ∗ +  ∗ =   (2)      ∗ +  ∗ = 0   (3)     wh e re,    ,    ,    ,   and      are   q - ax is   ro t or,   d - ax is   ro t or,   q - ax is   sta tor,   an d   d - axis   sta to r   c urren t   corres pondin gly ,   -   sta tor   flu x,     an d     are   sta tor   a nd   ma gn et ic   inducta nce   corres pondin gly .   Si nce   the   DF I G   sta to r   is   directl y   li nke d   with   the   gri d,   t he   sta to r   volt age   f orm ulas   ar e   ind ic at ed   as   ( 4).   T he   sta tor   powe r   (6)   ca n   be   dete rmin e d   base d   on   (3)   a nd   ( 5)      = 0   (4)      = ≃ ∗   (5)     = 3 2 (  ∗  ) = − 3 2 ∗ ∗ ∗    (6)     = 3 2 (  ∗  ) = 3 2 ∗ 2 ∗ ∗ ∗  − 3 2 ∗ ∗    (7)     wh e re, ,   ,  ,   an d      are   reacti ve,   act ive,   q - axis   and   d - axis   of   sta tor   vo lt age   corres pondin gly , - gri d   vo lt age , -   an gu l ar   sp ee d   c orres pondin gly .   Eq uation   (6 - 7)   s pe ci fical ly   no te s   that   sta tor   po wer s   in   te rms   of   q - axis   a nd   d - ax is   ro t or   c urre nts   ca n   be   a utonomo us l y   regulat ed.   Firs tl y,   re fer e nce   ro t or   cu rr e nt s   we re   determi ned   f or   the   co rr e spo ndin g   sta to r   po wer s .   T he   RS C   is   then   regu la te d   to   mai ntain   the   c urren t   of   t he   ro t or   e qual   to   the   ref e ren ce   le vels.   The   sta nd a r d   c ub e   la w   f or m ul a   giv e s   the   me chan ic al   powe r     f rom   the   wi nd   tu r bin e.     = 0 . 5 ∗ ∗ ∗ 3 ∗ ∁   (8)   Evaluation Warning : The document was created with Spire.PDF for Python.
            IS S N :   2088 - 8 694   In t J   P ow  Ele c  &  D ri   S ys t,   V ol .  12 , N o.   2 ,  J une  2021   :   11 5 0   –   116 1   1154   wh e re,   - blade s   swep t   area ,   - wi nd   velocit y,   - ai r   densi ty,   an d   ∁ - powe r   c oeffici ent. ∁ is   de pende nt   on   the   blade   ,   w he n   t he   pitch   an gle   of   the   bla de   is   con ti nual .   S ome   of   t he   va rio us   eq uatio ns   f or   est imat ing   the   ∁ .   In   this   st udy   ∁   is   obta ined   as   fo l lowe d,       ∁ = 0 . 5 ( − 5 . 60 )  ( − 0 . 170 ∗ )   (9)     wh e re   the     an d   the   s peed   of   ge ner at or   rati o   are   s pecifie d   f or   t he   tip   sp ee d   rati o   ( ) .   If   the   powe r   coeffic ie nt   is   maximize d,   wi nd   ene r gy   will   pro vid e   t he   ma ximum   me cha nical   powe r.     = ( ω ∗   ∗ )   (10)     = ( ω  ∗   ∗  )   (11)     The   integ rated   model   incl udes   a   4.0 KW   wind   t urbine   with   a   ra diu s   of   3.0 m   a nd   a   ma ximu m   T SR   of   5.660 .    an d   ω    is   the   opti mu m   acce pt able   rated   s peed   of   wi nd   an d   gen e r at or   s peed   corres pondin gly . ω    is   sel ect ed   as   19 8r a d/s,   w hich   c orrel at es   to   the   ge ner at or   r otati on al   s pee d   pe r      of   9.0m/sec.   Con se quently ,   the   gea r   rati o     as   est imat ed   from   ( 11)   is   give n   as   =   11 . 66   DF I G   is   implemente d   to   pro duce   4.0 kW   at   the   rat ed   wi nd   vel ocity.   I gnori ng   lo sses,   rate d   in put   (  _  ) ,   sta to r   ( _  )   an d   ro t or   ( _  )   po w er   are   co rr el at e d   as ,      _  = _  + _    (12)     and,     _  =  _  ( 1 + | _  | )   (13)     _  is   the   sli p - on   DF I G   rated   power,   tur bin e   s pe ed   is   110.0 ra d/sec   to   19 8.0ra d/sec.   T he   as so ci at ed   sli p   range   for   the   gen e rato r   is   - 0.267   to   0.30.   The refor e ,   the   maximal   _    st at or   powe r   e quivale nt   to       at   sli p    =   - 0.2670   is   3.1 5kW .   A   w ound   ro t or   m otor   with   a   capaci ty   3.0 kW   is   e nough   f or   a   wind   tu r bin e   of   4.0kW;   T he   RSC   sat isfie s   the   reacti ve   power   de man d.     3.3.   DC - bu s   vo lt ag e   Op ti m um   sli p   is   0.3 0   wh ic h   is   eq ual   to   11 0.0r a d/sec   s pe ed   of   r otor   the   maxim al   volt age   of   r otor   _  = 0 . 3 ∗ 415 − 124 . 50 .   T he   DC - vo lt a ge   of   batte r y     is,     > { [ 1 . 64 ∗  ] }   (14)     RSC   &   GS C   li ne   volt age      is   chosen   0.125 kV,   m odulati on   ind e x     is   cho se n   unit y,   a nd   t he n     sh oul d   al so   be   more   tha n   0.2 04kV.     is   sel ect ed   for   0.240 kV   in   the   de velo pe d   sc heme .       4.   CONTR OL   A LGORIT HM   Or ie nted   vect or   c on t ro l   ap proach   for   t he   c on t ro l   of   t he   a utonomo us   hy br i d   s olar - wi nd   s ys te m   as   disp la yed   in   Fi gure   1.   T his   c on t ro l   a ppr oac h   is   co mmit te d   to   t he   powe r   conve rter   c ons ist ing   of   the   ba ck - to - back   co nverter ,   cat eg or iz e d   i nto   an   RSC   an d   GS C.   The   grid - vo lt age - ori e nted   vecto r   regulat ion   is   re qu i red   to   mana ge   the   G S C   to   kee p   the   s te ady - sta te   vo l ta ge   of   the   DC   bus   a nd   to   a dj us t   reacti ve   po wer   on   the   gr i d   side .   Also ,   the   sta to r - vo lt age - or ie nt ed   co ntr ol   sch eme   offe rs   a   st able   f un ct io n   of   DFI G   to   regu la te   the   RSC   on   the   sta tor   e dg e   f or   reacti ve   a nd   ac ti ve   powe r   ma nag e ment   [ 24 ] ,   [ 25].     5.1.   Grid   side   c onverter   co nt r ol   The   vecto r   c ontr ol   ap proac h   empl oyed   sat isfie s   the   two   ke y   ai ms   in   the   GS C .   Fir stl y,   mana ge   t he   vo lt age   of   t he   DC   bus ,   sec ondly   mana ge   t he   reacti ve   pow er   interc ha nge d   two - wa ys   be tween   t he   ro t or   a nd   gr i d   si de.   T herefo re,   its   in dir ect   axis   el eme nt   becomes   zer o   by   as so ci at in g   t he   gri d   V oltage   Vecto r   wit h   t he   sy nc hro nous   di rect   axis   fr a m e.   T he   GS C   c on t ro l   f or m ula s   an d   gri d   po wer   re pr es enta ti on s   a re   s how n   in   the   belo w   e qu at i on   ( 15 - 20 ).   Evaluation Warning : The document was created with Spire.PDF for Python.
In t J  P ow Elec   & Dri S ys t   IS S N: 20 88 - 8 694       Desig n a nd control  of  gr id - c onnected  s ola r - wi nd integ ra te d  c on ve rsio n  s yst em  …   ( Arju n  K umar GB )   1155      = − (  + ∗   ) +  +    (15)        = − (  + ∗   ) −    (16)     = 1 . 5 ∗ (   +   )   (17)     = 1 . 5 ∗ (   −   )   (18)      = 0     = 1 . 5 ∗     (19)     = − ( 1 . 5 ∗   )   (20)     Wh e re,        an d      are   vecto r   el em ents   of   the   GSC   outp ut   volt age,  ,    ,   a nd    are   gri d   volt ag e   and   cu rr e nt   c orres pondin gly.   De pendin g   on   the   in dicat ion   of   a   non - ze ro   sli p   ( S )   rati o,   a   portio n   of   t he   real   powe r   pro du ce d   by   DFIG   is   exch a nged   with   t he   gr i d   via   t he   ro t or   that   m ay   pro vid e/ c onsu me   gri d   pow er   in   above   an d   bel ow   rate d   s ync hro nous   mode s,   acc ordin gly.   T he   (19 ) - ( 20)   in dicat es   that   real   pow e r   a nd   accor dingly   DC   bus   volt age   cou l d   be   re gu l at ed   via    ,   wh il e      can   re gu la te   the   gri d's   reac ti ve   po wer   fl ow.   Figure   4   il lustr at es   this   te ch ni qu e .   T hus,   t he   current   c ontr oller   de velo pm e nt   co mes   from   (21 ) ,   ( 22) .      = −   −  ∗ ∫   − (  +  )   (21)      = −   −  ∗ ∫   − (  )   (22)     Her e ,    =  ∗ −     =  ∗ −  .       The   integ ral   a nd   pro portio nal   com pone nt   of   t he   i nter nal   c urren t   lo op   is      an d    res pecti vely .   T he   angular   or ie ntati on   volt age   of   the   gr id   ca n   be   ide ntifie d   th r ough   a   P LL,   with   a   bette r   sta nd a r d   in   e xpre ssion s   of   ste adine ss   a nd   tran sie nt   re act ion .   Su c h   a   locke d   a ng le   is   util iz ed   to   c on ver t   de vice   pa r amet ers   int o   the   d - q   ref e ren ce   po i nt .   T he   outp ut   vo lt age   of   the   PI   regulat or   keeps   t he   ste a dy   vo lt age   of   the   DC   bu s ,   wh ic h   measu res   the   e rror   am ong   t he   ref ere nce,   a nd   determin ed   DC   bus   vo lt age   and   pro du ce s    ∗ .   Althou gh    ∗   is   fixe d   to   null   to   mit igate   t he   reacti ve   powe r   on   t he   gr i d   edg e ,   the   G SC   supp li es   t he   r equ i red   ma gn e ti zi ng   energ y   via   the   DFI G   ro t or.   Ulti mate ly   the   cal culat ed   re f eren ce (  , ∗    ∗ )   a nd   gri d   c urre nt   (  ,  )   are   con t rasted   a nd   handled   by   i nt ern al   c urre nt   PI   re gula tors   to   pro du ce   suffici ent   G SC   sig nal s.           Evaluation Warning : The document was created with Spire.PDF for Python.
            IS S N :   2088 - 8 694   In t J   P ow  Ele c  &  D ri   S ys t,   V ol .  12 , N o.   2 ,  J une  2021   :   11 5 0   –   116 1   1156   Figure   4 .   G rid   side   c onver te r   con t ro l   5.2.   Rotor   side   c onver ter   c on tr ol   The   R SC   is   e ssentia l   f or   re gu la ti ng   t he   DF I G   in   gri d   interco nnect ed   DFI G - ce ntere d   WECS   to   colle ct   the   op ti mal   acce ssible   and   no minal   m echan ic al   pow er   in   the   wi nd   tur bin e   a nd   to   keep   the   unit   powe r   factor   in   t he   st at or .   By   i gnor i ng   the   sta to r's   resist ance,   an d   co ns ide rin g   a   balance d   gr i d   vo lt age ,   the   sta tor's   mag netic   flu x   is   assume d   to   be   c onsta nt   wh ic h   is   e nforce d   by   t he   gr i d.   With   vecto r   of   sta tor   volt age   is   or ie nted   t hro ugh   the   di rect   axi s,   the n   t he   sta t or   flu x   volt age   descr i bed   as.      = ∗    (23)      = − ∗    (24)     Since   the   sta to r's   act ive   a nd   r eact ive   pow er   is   pro vid e d   in :     = − 1 . 5 ∗  ∗     (25)     = 3 2  2  + 3 2        ( 26)     The   ste a dy   sta te   eq uation   f or   r otor   vo lt age   is,      =  +  ∗   − ( ω r   )   (27)      =  +  ∗   + (   +   ∗   )   (28)     Wh e re,   =  − ( 2  ) ,   is   le akag e   co ef fici ent   of   mac hi ne .      re gula te s   sta tor   reacti ve   powe r,   wh e reas   the   sta tor   act ive   pow er   is   re gula te d   by    from   the   sta tor   po wer   eq ua ti on   ( 25 )   a nd   ( 26).   Simi la rly ,   by   inco rpor at in g   M PP T,   the   re qu i red   opti mum   el ect ro - ma gnet ic   tor qu e   c an   co mp el   t he   DF I G   to   pro duce   the   maxim um   acce ssible   po wer   onto   t he   gr i d.   T he   e qu at io n   of   tor qu e   is   re pr e sented   as   (29) ,        = 1 . 5 ∗ ∗  ∗     (29)     The   c ontr ol   te chn i qu e   of   R S C   is   outl ined   in   Fi gure   5.   If   t he   sta to rs   f un c ti on   at   unit y   powe r   facto r,   the   s upply   of   r eact ive   po wer   from   the   sta tor   ed ge   to   t he   gr i d   is   adj us te d   to   zer o.   Th us      can   be   de rive d   fro m   equ at io n   (26 ).   To   determi ne   the   ma ximal   powe r   operati ng   points   for   the   tu rb i ne,   it   is   achieve d   fro m   the   tur bin e   powe r   curve   c har a ct er ist ic s.           Figure   5 .   Roto r   side   c onve rter   con t ro l.   Evaluation Warning : The document was created with Spire.PDF for Python.
In t J  P ow Elec   & Dri S ys t   IS S N: 20 88 - 8 694       Desig n a nd control  of  gr id - c onnected  s ola r - wi nd integ ra te d  c on ve rsio n  s yst em  …   ( Arju n  K umar GB )   1157       5.3.   Wind   MPPT   In   this   sc heme ,   M PP T   is   at ta ined   by   mai ntaining   the   maxi mu m   tip   s peed   rati o;   it   is   t he   rati o   of   t he   tur bin e   vel ocity   at   the   tip   of   a   bla de   to   wind   sp ee d,   t ow a r ds   its   ma ximum   value,   i.e.   by   a dju sti ng   t he   m aximal   ro t or   s pee d   re f eren ce   ∗   to ward s   its   correspo ndent   e valuate d   wind   velocit y ,   it   can   be   co mputed   from   lookup   ta bles .   The   co ntr oller   la w,   wh e n   ∗   is   ob ta ine d   an d   the n   co ntras te d   with   real   r otor   mech anic al   velocit y,    ∗   is   a nalyze d   util iz ing   a   propo rtio nal - inte gr al   co ntr oller,   co ns e qu e ntly,    ∗   ca n   be   deter mine d   from   (29).   T he n,   the   real   r otor   cu rr e nts    and    are   co ntraste d   to   the   ref e ren ce   ro t or   c urren ts  ∗   and    ∗ unti l   b ei ng   ma na ge d   to   util iz e   the   inter nal   cu rr e nt   co ntr oller   of   P I.   U nd e r   si mil ar   pr ocedure s   to   t ho se   util iz ed   f or   GS C,   a nd   t hen   introd uced   two   cr os s - te rms,   to   eve ntu al ly   pro du ce   the   c ontr ol   sig nals   in   the   RSC .     5.4.   SPV S - MPPT   control   techni que   The   gr eat est   pr ob le m   with   S P VS   is   that   the   ou t pu t   powe r   is   highly   de pended   on   the   l oa d   po wer   a nd   cl imat e   ci rcu m sta nces.   T hus,   a   DC/DC   c onver te r   is   bei ng   us e d   to   maint ai n   the   maxim um   powe r   from   PV   irres pecti ve   of   cha ng e s   in   PV   ci rc um sta nc es   [ 26 ] - [ 2 7 ].   I nv e sti gators   ha ve   im pleme nt ed   di ff e ren t   M PP T   fr ame w orks   a nd   te ch niques   over   t he   past   fe w   de cades .   A   вв   co nverte r   is   de ployed   in   t his   resea rc h   to   at ta in   the   opti mum   powe r   outp ut   of   the   PV   s ys te m.   Fig ur e   6   il lustrate s   the   c ontr ol   sc hemati c   for   the   в - в   c onve rter.           Figure   6 .   Co ntr oller   diagram   of   bu c k – bo os t   c onve rter       The   Pe rtu rb   &   ob se r ve   ( P & O)   M P PT   el ement   is   a   f unda mental   pa rt   of   this   fi gure.   In   co mb i nation   with   t he   instan ta neous   cu rr e nt   an d   volt age   of   t he   SP V   s ys t em,   t his   el em e nt   ca n   il lustrate   a   pe rtinent   volt age   ref e ren ce .   Add it ion al ly,   t he   r efere nce   volt age   of   this   el e ment   wil l   be   pro gr essi vely   i ncr ease d   to   tr ack   the   op ti m um   val ue   by   t his   el em ent.   T he   в - в   c onve rter   c ontr ols   to   at ta in   the   volt age   of   t he   SP V   s ys te m   at   its   ref e ren ce   valu e .   T his   te ch niq ue   has   bee n   employe d   bec ause   of   its   use   of   a   simpli s ti c   but   of te n   r obus t   appr oach.       5.   RESU LT S   A ND   DI SCUS S ION     The   e ff ic ie nc y   of   t he   pr ese nt ed   A uton omo us   Hybr i d   S ol ar - Win d   S ys te m   ( AHSW S)   in   va rio us   mecha nical   a nd   el ect rical   s yst ems   is   in dic at ed   in   fig ur e s   7 - 8 .   T he   sim ulati on   desig n   of   the   im plemented   sy ste m   is   a   built - in   SIMP O WER   s of t war e   kit   of   M A TL AB.   T he   PV   pa nel   an d   wind   tur bin e   a re   si mu la te d   util iz e   the   imp la nted   M AT L AB   featu re.   Further more,   t he   eff ic ie nc y   of   t he   A HSWS   at   var i ou s   wind   sp ee ds   and   regular   s ol ar   irrad ia nce   as   disp la yed   in   fig ure   7 - 8   r especti vely .   Both   sit uatio ns   examine   t he   M PP T   appr oach   on   di ff e rin g   wind   s pe eds   a nd   PV   ra diati on .     5.1.   Effici ency   of   ahsws   in   dif feri ng   PV   ra diat i on   with   c on tin ua l   lo ad   and   wind   veloci ty   The   s ys te m   e ffi ci ency   of   A H SWS   in   diff e ri ng   PV   ra diati on   with   co ntin ua l   load   a nd   wi nd   vel ocityis   disp la yed   in   Fi gure   7 .   The   a bove   sc heme   is   op e rati ng   at   a   wind   velo ci ty   of   7.0m /s   an d   s olar   gl ob al   irr a diati on   of   70 0.0W/m 2 at   ti me   t= 5.0s ,   the   s olar   irr adiat ion   is   rai sed   to   nea rly   80 0.0W/m 2   at   the   pro portion   of   400.0W/ m 2 /s   a nd   a fter ward,   it   is   decr ea sed   to   70 0.0W/m 2   a gain   sta rtin g   f r om   t= 6.2 0s   at   t he   simi la r   le ve l.   T he   dev ic e   is   sup pose d   to   sup ply   rated   fr e quenc y   a nd   volt age   f rom   the   P V,   ut il iz ing   an   MPP T   co ntr oller.       Evaluation Warning : The document was created with Spire.PDF for Python.
            IS S N :   2088 - 8 694   In t J   P ow  Ele c  &  D ri   S ys t,   V ol .  12 , N o.   2 ,  J une  2021   :   11 5 0   –   116 1   1158                 Figure   7 .   A HSWS   e ff ic ie nc y   at   changin g   so l ar   ir rad ia ti ons       5.2.   Effici ency   of   AHSWS   in   dif fering   win d   ve locity   wit h   c ontinu al   lo ad   and   PV   r ad i at i on   The   s ys te m   ef f ic ie ncy   of   A H SWS   in   dif fer i ng   wi nd   vel oci ty   with   c on ti nu al   load   an d   PV   ra diati on   is   disp la yed   in   Figure   8 .   At   t he   mo me nt   of   be gi nn in g,   s olar   pa nels   ar e   e xpose d   to   s olar   rad i at ion   of   80 0.0 W/ m2 ,   and   wind   tu rb i nes   to   wind   ve locit y   of   7.0 m/ s .   The   3ϕ   bala nced   l oads   of   1.0kV AR   an d   4.0kW   in   t he   s ta r   li nk   are   co nnect ed   at   the   c om m on   co upli ng   P oin t.   At   the   f ollow i ng   wi nd   velocit y,   the   gen e rato r   velo ci ty   of   153.3 4r ad/s   is   achieve d.   In   c ompli ance   with   at   4.8 5s ,   t he   w ind   vel ocity   is   increase d   to   7.50m/s   as   well   as   the   sp ee d   of   t he   ge ner at or   is   raise d   to   16 6.7   rad/ s .   Win d   velocit y   was   decr ea se d   to   7.0 m/s   at   7.20 s ,   with   t he   same   le vel   of   s hift.   Althou gh,   the   discre pan c y   in   the   ge ne rator   outp ut   an d   t urbine   in   the   el ect r ic al   gr id;   volt age   a nd   fr e qu e nc y   are   not   a ff ect e d   by   the   dif fer e nc e   in   wi nd   ve locit y.   Af te r   s ever al   c ycles   t he   tra ns ie nts   die   out   dev ic e   reac hes   its   maxim um   sp ee d   propo rtion al   to   _ max     dis playing   an   M P PT   sy ste m   ope rati ng   in   t he   wind   con t ro l   s ys te m .     4 4 . 5 5 5 . 5 6 6 . 5 7 4 6 8 10 T i m e   ( s ) G W   ( k W / m 2 )     3 3 . 5 4 4 . 5 5 5 . 5 6 220 240 260 T i m e  ( s ) V t  ( V ) 0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 4 4 . 5 5 5 . 5 6 6 . 5 7 0 4 6 8 T i m e  ( s ) I b ( A ) 4 4 . 5 5 5 . 5 6 6 . 5 7 7 . 5 48 50 52 T i m e   ( s ) f   ( H z )     4 4. 5 5 5. 5 6 6. 5 7 -5 0 5 T i m e   ( s ) P   ( kW )     P L   ( K W ) P B   ( K W ) 4 4 . 5 5 5 . 5 6 6 . 5 7 -5 0 5 6 T i m e   ( s ) P G   ( K W )     P w ( K W) P s o l ( K W) Evaluation Warning : The document was created with Spire.PDF for Python.
In t J  P ow Elec   & Dri S ys t   IS S N: 20 88 - 8 694       Desig n a nd control  of  gr id - c onnected  s ola r - wi nd integ ra te d  c on ve rsio n  s yst em  …   ( Arju n  K umar GB )   1159                   Figure   8 .   A HSWS   e ff ic ie nc y   at   changin g   wi nd   vel ocity       6.   CONCL US I O N     A   3ϕ   4 - wire   AHSW S   m odel   has   been   de velo ped,   wh i ch   dem on st rates   its   eff ic ie nc y.   A   detai le d   desig n   pro cess   is   pro vid e d   to   en sure   accu rat e   rati ngs   a nd   s pecifica ti ons   f or   the   c ompon ents   of   t he   A H SWS.   The   pro po se d   AHSW S   wi nd   tur bin e   with   D FI G   an d   s olar   PV   pan el   is   be en   est ablis h   ab le   to   delive r   qual it y   powe r   to   the   us ers .   T he   de vice   has   an   M PP T   f unct io n   to   ob ta in   opti mu m   ef fici ency.   T he   impl emented   AHSW S   has   be en   sho wn   to   a chieve   op ti m um   eff ic ie nc y   unde r   va rio us   m echan ic al ,   el ec tric al ,   ci rcu mst ances.   The   AHSW S   has   dem onstra te d   the   ca pa bili ty   of   trac king   maxim um   po wer,   ne utral   c urren t   mit igati on,   the   rem ov al   of   ha rm on ic s,   a nd   l oad   balancin g   in   a dd it io n   to   con t ro l   of   fr e quenc y   an d   vol ta ge;   un der   va rio us   mecha nical ,   el ect rical ,   dyna mic   co nd it io ns.         4 4 . 5 5 5 . 5 6 6 . 5 7 7 . 5 8 6 7 8 T i m e ( s ) V W   ( m / s )     4 4 . 5 5 5 . 5 6 6 . 5 7 7 . 5 8 140 160 180 T i m e   ( s ) ( s ) W R   ( R a d / s )     3 3 . 5 4 4 . 5 5 5 . 5 6 220 240 260 T i m e  ( s ) V t  ( V ) 0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 0 0 . 1 0 . 2 0 . 3 0 . 4 0 . 5 0 . 6 0 . 7 0 . 8 0 . 9 1 4 4 . 5 5 5 . 5 6 6 . 5 7 7 . 5 8 0 . 4 2 0 . 4 3 0 . 4 4 0 . 4 5 0 . 4 6 T i m e   ( s ) C P     4 4 . 5 5 5 . 5 6 6 . 5 7 7 . 5 8 -2 0 2 4 6 T i m e ( s ) P G   ( K W )     P S o l a r   ( kW ) P W i n d   ( K W ) 4 4 . 5 5 5 . 5 6 6 . 5 7 7 . 5 8 - 2 0 0 20 T i m e   ( s ) I B   ( A )     4 4 . 5 5 5 . 5 6 6 . 5 7 7 . 5 8 -6 -4 -2 0 2 4 6 T i m e   ( s ) P   ( k W )     P L o a d   ( K W ) P B a t   ( K W ) Evaluation Warning : The document was created with Spire.PDF for Python.