2. Controlled Rectifiers

Transcription

1 strt Interntionl Journl of dvned Tehnoloy & Enineerin Reserh (IJTER) NLYSIS OF TOTL HRMONIS DISTORTION USING MULTIPULSE ONVERTER Hemnt Dhnuk nd Surh Gupt Deprtment of Eletril nd Eletronis Enineerin, Tehnorts Institute of Tehnoloy nd Siene, The work presents deep effort towrds nlyzin line ommutted ontrolled multipulse onverters for solvin the hrmoni prolem. The effet of inresin the numer of pulses on the performne of to D onverters hs een nlyzed. For performne omprison the mjor ftors onsidered re the ripple perente, form ftor nd the totl hrmoni distortion (THD). The effets of lod vrition on multipulse to D onverters hve lso een investited. This work presented,, 4 nd pulse onverters. Key Words: Multipulse onverter, Hrmonis distortion, Ripple ounters.. Introdution Threephse ontrolled retifiers hve wide rne of pplitions, to lre hih volte diret urrent (HVD) trnsmission systems from smll retifiers. They re used for eletrohemil proesses, wide rne of motor drives, ontrolled power supplies, trtion equipment nd other pplitions. The ommuttion proess n e lssified into two importnt teories nmely: Lineommutted ontrolled retifiers nd Foreommutted pulse width modulted retifiers There re severl tehniques primrily dopted for the mitition of hrmonis in phse onverter nd multipulse onverters fll in the sme teory of remedil mesures. Multi pulse onverters re the most fundmentl solution for hrmoni prolem in threephse onverter system. With the dvnements in tehnoloy dvnes these onverters nd other power eletroni devies with interted mneti feturin hih input power qulity nd etter performne would e required y mny industril, ommeril pplitions, power supplies. The effet of inresin the numer of pulses of to D onverters diretly lters its performne prmeters like ripple perente, form ftor nd the totl hrmoni distortion. Multipulse onverters re onverters providin more thn six pulses of D volte per yle from input or the onverter hvin more steps in input urrent thn tht of six pulse ride retifier supply urrent. Phse shiftin trnsformers re used to derive multipulse phse supply from threephse mins usin different omintions of trnsformer windins suh s str, delt, ziz, polyon, fork et. In this thesis we use ziz trnsformer. The phseshiftin trnsformers ply key role in the multipulse retifier's performne. Jiopu et.l [] disussed ommonly used si onnetions of phseshiftin trnsformer, suh s Sott, polyon, str/delt, extendeddelt nd ziz nd ve the nlyses nd omprisons etween them. Fousin on pulse phseshiftin trnsformers, the reserh hihlihted possile strteies from si onnetions to pulse phseshiftin trnsformers whih illustrte the evolution nd its si priniples whih my e extended to hiher pulse onverters. Sinh et.l [] nlyzed the performne of multipulse eletroni lod ontroller for isolted synhronous enertor, s lod ontroller onventionl eletroni sed six pulse unontrolled retifier ontins lre ontent of hrmonis. omprtive study of three phse ontrolled multi pulse onverters ws presented y [4] for iomss, s turine, wind system sed power plnt, diesel, hydro,, nd inorported input urrent shpin of ontrolled retifier usin multipulse urrent shpin onept. The uthor Xien et.l [] introdued the reliztion of phseshiftin of the multipulse onverter trnsformer nd the method for lultin streth phseshiftin nle, trinle volte nd the numer of windins nd nlyzed the simultion for the 0pluse retifition system sed on this trnsformer. rvindn et.l [] proposed two 4pulse retifier topoloies sed on phse shiftin usin onventionl mneti over PSD environment.. ontrolled Retifiers There re two types of onversion tehniques, one is unontrolled in whih diodes re implemented nd other is ISSN No: 505 Volume 5, Issue, Nov. 05

2 ontrolled in whih thyristors re implemented respetively [].The performne improvement is hieved for totl hrmonis distortion (THD) in input urrent, D volte ripples nd form ftor. Threephse ontrolled retifiers hve wide rne of pplitions, to lre hih volte diret urrent (HVD) trnsmission systems from smll retifiers. They re used for eletrohemil proesses, wide rne of motor drives, ontrolled power supplies, trtion equipment nd other pplitions.. Threephse Hlfwve Retifier Interntionl Journl of dvned Tehnoloy & Enineerin Reserh (IJTER) Threephse Fullwve Retifier Prllel onnetion vi inter phse trnsformers permits the implementtion of retifiers for hih urrent pplitions. For hih volte series onnetion is lso possile, s shown in the fullwve retifier of Fi.. With this rrnement, it n e seen tht the three ommon thode vlves enerte positive volte with respet to the neutrl, nd netive volte is produed y the three ommon node vlves. To ontrol the lod volte, the hlfwve retifier uses three ommonthode thyristor rrnements. The thyristor will ondut (ON stte), when the nodetothode volte VK is positive nd firin urrent pulse ig is pplied to the te terminl. n nle ontrols the lod volte y delyin the firin pulse. Fi : Threephse fullwve retifier (). Hrmoni Distortion Fi : Instntneous D volte VD, firin nle nd vere d volte VD of hlf wve retifiers. The thyristor oes to the nonondutin ondition (OFF stte) when the followin thyristor is swithed ON, the urrent rehed netive vlue. The urrents of the lineommutted retifiers re fr from ein sinusoidl. For exmple, the urrents enerted from the phse full wve retifier hve the followin hrmoni ontent. (4) (). Sixpulse or Doule Str Retifier The thyristor side windins of the trnsformer shown in Fi., form sixphse system, resultin in sixpulse str point (midpoint onnetion). Disrerdin ommuttion overlp, eh vlve onduts only durin 0 per period. () Some of the hrteristis of the urrents, otined from Eq. (.5) inlude: (i) the sene of triple hrmonis; (ii) the presene of hrmonis of order k ± for inteer vlues of k; (iii) those hrmonis of orders k re of positive sequene; (iv) those of orders k re of netive sequene; (v) the rms mnitude of the fundmentl frequeny is, (5) nd the rms mnitude of the nth hrmoni is (). Formultion of Pulse onverters Fi : Sixpulse retifier The pulse retifier ws otined with 0 phse shift etween the two seondry trnsformers. The sis for inresin pulse onfiurtions is provided y the prllel trnsformers. For instne, the opertion of 4 pulses is ISSN No: 505 Volume 5, Issue, Nov. 05

3 hieved y mens of four trnsformers with 5 phse shift, nd 4pulse opertion requires eiht trnsformers with.5 phse shift. n inenious nd very simple wy to reh hih pulse opertion is shown in Fi.4. This onfiurtion is lled d ripple reinjetion. It onsists of two prllel onverters onneted to the lod throuh multistep retor. The retor uses hin of thyristorontrolled tps, whih re onneted to symmetril points of the retor. Interntionl Journl of dvned Tehnoloy & Enineerin Reserh (IJTER) 4. Simultion Model of Pulse onverters The present d onverters re osteffetive for universl line nd ommeril volte pplitions ut re unrelile nd fult prone for hiher power pplitions. Thus, to lihten these prolems, multi ste nd multi pulse onverters hve een developed with the flexiility to ompliment with ustom power swithin modes. For hih nd ultr hih volte levels the soft swithin multi pulse onverters offers ttrtive merits euse the omponent ount suffies with the ost of the system. 4. SixPulse onverter Fi 4: D ripple reinjetion tehnique of pulse opertion six pulse thyristorized onverter iruit is shown in Fi, elow. strziz trnsformer is used t input side of the onverter in order to provide vrile phse shift if desired. The thyristors loted t the retor is fired t the riht time; hihpulse opertion is rehed. The pulse level opertion depends on the numer of thyristors onneted to the retor. The si level of opertion is multiplied to the two onverters. S_ S Soure S_ Ziz Trnsformer (0 de ) V VseIse F F.. _Lod. HVD wer Trnsmission The use of HVD systems for interonnetions of synhronous systems is n interestin pplition. Some ontinentl eletri power systems onsist of synhronous networks suh s those for the Texs, Quee networks in North meri, nd islnds lods suh s tht for the Islnd of Gotlnd in the lti Se mke ood use of the HVD interonnetions. _M Ripple Mesurement Fi. Six pulse ontrolled onverters with resistive lod 4. TwelvePulse onverter Divide Vo V Ripple Form Ftor Mesurement In Men Men Vlue twelve pulse thyristorized onverter iruit is shown in Fi. Two strziz trnsformers re used t input side of the onverter in order to provide vrile phse shift lon with two universl rides. R F Fi 5: Typil HVD iruit system F.. V _Soure _M VseIse Ziz Trnsformer (5 de ) _Lod _ Vo Ripple Ripple Mesurement R Ziz Trnsformer (5 de ) F V VseIse Fi. Twelve pulse ontrolled onverters with resistive lod F.. V Form Ftor Mesurement Divide In Men Men Vlue ISSN No: 505 Volume 5, Issue, Nov. 05 4

4 4. Twenty FourPulse onverter Interntionl Journl of dvned Tehnoloy & Enineerin Reserh (IJTER) 5. Results nd Disussion The elow Fi, whih is shown elow is hvin twenty four pulse thyristorized onverter iruits. lon with two universl rides in eh roup t input side the onverter requires 4 strziz trnsformers, two on eh positive phse roup nd netive phse roup The six nd pulse onverter model sed upon simultion for n output power of 5000 wtts provided for voltes, lod urrent nd soure urrent, re illustrted in Fi.0. F F.. Ziz Trnsformer (5 de ) V VseIse P F F.. 4 V 5 Ziz Trnsformer (.5 de ) VseIse P F F.. Ziz Trnsformer (5 de ) V VseIse N F F Ziz Trnsformer (.5 de ) V VseIse N Fi. Twenty Four pulse ontrolled onverters with resistive lod 4.4 Thirty SixPulse onverter The simultion model for thirty six pulse thyristorized onverter iruit is shown in Fi.9. The onverter requires strziz trnsformers t input side of the onverter, in positive phse roup nd in netive phse roup lon with three universl rides in eh roup 4 5 Ziz Trnsformer (5 de ) Ziz Trnsformer (5 de ) Ziz Trnsformer (5 de ) Fi. 9. Thirty six pulse ontrolled onverters with resistive lod F V F V F VseIse V VseIse VseIse F.. F.. F.. P P Fi.0.Ripple ftor, form ftor nd men vlue of volte respetively of nd pulse enertor ISSN No: 505 Volume 5, Issue, Nov. 05 5

5 Interntionl Journl of dvned Tehnoloy & Enineerin Reserh (IJTER) Fi..Ripple ftor, form ftor nd men vlue of volte respetively of 4 nd pulse enertor. ONLUSION n nlysis of simultion results ws performed nd the followin onlusions n e drwn without loss of enerlity.. Inresin the numer of onverter pulses redues the volte ripples. [] R Mury, P rwl, S.P Srivstv, Performne investition of Multipulse onverter for Low Volte Hih urrent pplitions, IEEE Interntionl onferene on omputer Siene nd utomtion Enineerin (SE), pp, 0. [] P.K Sinh, Y.K huhn, Performne nlysis of multipulse eletroni lod ontrollers for selfexited indution enertor, Interntionl onferene on Enery Effiient Tehnoloies for Sustinility (IEETS), pp990, 0. [4] hturvedi,; D Msnd,.; Gupt, S.; Tiwri, S.; Jin, M., omprtive nlysis of three phse D ontrolled multi pulse onverter, IEEE Students' onferene on Eletril, Eletronis nd omputer Siene (SEES), pp 4, 0. [5] Vlderr;no, ; Rmirez, J.M.; orre, R.E., new 4pulse VS onfiurtion usin multilevel D volte reinjetion for espeil pplitions, IEEE Interntionl onferene on Industril Tehnoloy (IIT), pp.50, 00. [] Xien M; ho Li; Lin i; Yin Liu, nlysis nd Mtl Simultion of 0Pulse Retifition System sed on Streth Trinle Trnsformer, Interntionl onferene on Eletril nd ontrol Enineerin (IEE), pp 5, 00. [] N rvindn,. Guh, Novel topoloies of 4 pulse retifier with onventionl trnsformers for phse shiftin, st Interntionl onferene on Eletril Enery Systems (IEES), pp 04, 0. [] I. Sef,; ltin, N.; olk, I;zdemir, S., pulse ontrolled retifier: se study on UPS, th Europen onferene on wer Eletronis nd pplitions, pp 9, Form ftor is lso improves thouh insinifintly.. The hrmonis in the supply system re lmost eliminted. 4. The volte ripples inrese s the firin nle is inresed. Referenes [] Wen Jiopu; Hihon Qin; Shishn Wn; o Zhou, si onnetions nd strteies of isolted phseshiftin trnsformers for multipulse retifiers: review, sipifi Symposium on Eletromneti omptiility (PEM), pp 05 0, 0. ISSN No: 505 Volume 5, Issue, Nov. 05