[Naik, 4(9): Septembe 17] SSN 348 834 DO- 1.581/zenodo.9984 mpact Facto- 4. GOBA JOURNA OF ENGNEERNG SCENCE AND RESEARCHES NTERFACE USNG DC-DC HGH STEP-UP NON-TRANSFORMER RESONANT CONVERTER FOR GRD CONNECTED NON-CONVENTONA ENERGY SOURCES Guguloth Rajende Naik *1 & Pudai Mahesh *1& Assistant Pofesso, Depatment of Electical & Electonics Engeeg, KTS W, Telangana, ndia ABSTRACT n this wok, teface usg DC-DC high Step-up non-tansfome esonant convete fo gid connected Nonconventional enegy souces is poposed. t is a pomisg option to make use of enewable enegy souces to be connected to HVDC gid which equie high voltage & high powe enewable enegy souces. A dc-dc step-up convete is used as majo equipment which opeates as a esonant convete with high voltage ga. The voltage stess on the semiconducto devices & switchg losses is educed by zeo voltage switchg (ZVS) tun-on and tun-off method and also with zeo cuent switchg (ZCS) tun-off of convete switches. The selection of equied paametes fo the dc-dc step-up esonant convete is pesented this pape. The poposed convete system opeation, pefomance and simulation esults have been successfully veified by usg MATAB/Simulk. Keywods: dc-dc step-up convete, paallel C esonant tank, soft switchg (zeo voltage & zeo cuent). NTRODUCTON Now a day s, with the apid cement of utilization of electical enegy, the geneation of electical enegy by the conventional method is high cost with less efficiency. So it is essential to depend on the non-conventional enegy souces such as sola, the wd and etc. The diffeent enegy stoage devices and enewable enegy souces ae havg low DC voltage, like photovoltaic (PV) cells, supe-capacito, battey and fuel cells ae usually equied to be stepped up to a high-level AC voltage fo dustial applications. Moeove, enewable enegy souces such as sola and wd, the common issue is the lage vaiations of output powe, and the lage scale connection of the enewable souces to the powe gid is moe challengg fo the taditional electical equipment, gid opeation and stuctue. Recently, tensive eseach on DC-DC convetes has been cayg out to implement fo convesion and extensive voltage egulation. At pesent, the geneation of voltages ove the dc stages the equipment of the enewable enegy souces is vey low, such as seveal hunded volts. Sce, HVDC gids ae equied high voltage high powe electical enegy, stepup dc-dc convetes ae employed. The geneated enewable enegy passes though the step-up DC-DC convetes and fally connected to HVDC gid by usg special connectos. These connectos not only tansmit electical enegy but also isolate o buff kds of fault conditions. These ae one of the key equipment the DC gid. Fo high powe high voltage step-up DC-DC convesion, conventional boost convete and tansfome-based switched-mode powe supplies (SMPSs), such as Fly-back and Fowad convetes etc., ae nomally used because of thei simple topology. n geneal, with high duty cycle, as a boost convete is opeated, the output voltage is high. But with high amplitude, a shot pulse cuent is sustaed by a ectifie diode, which ceases the evese ecovey losses of a diode and electomagnetic tefeence (EM) poblem. And also equies the high atg of switches o powe semiconducto devices, which also ceases the conduction and switchg losses. The powe semiconducto switches dug tun on and off pocess, the entie load cuent is caied by the switches. Then these switches ae subjected to high switchg stesses which esults high switchg powe losses. The step-up dc-dc convetes ae used automotive applications with the help of bidge topology i.e., the full bidge o half bidge, with high 131 (C)Global Jounal Of Engeeg Science And Reseaches
[Naik, 4(9): Septembe 17] SSN 348 834 DO- 1.581/zenodo.9984 mpact Facto- 4. fequency step-up atio tansfome. Due to this, the cost, weight, and volume of the convete ae ceased with less efficiency. To ovecome all these defects, a high step-up dc-dc tansfome less esonant convete is used this wok. By addg an C paallel esonant convete to the step-up dc-dc convete, the voltage and/o cuent undego to a zeo-level peiodically. f the powe semiconducto devices/switches of the convete ae tuned on & off at zeo voltage and/o zeo cuent, then the voltages stess on devices/switches, switchg losses and EM geneated etc., ae dastically educed. Hence the tems zeo voltage switchg (ZVS) o zeo cuent switchg (ZCS). t also impoves the pefomance of the convete with soft switchg technology and efficiency with less cost & weight. n this wok, the put fo DC-DC convete is geneated fom sola panel and the simulation esults ae povided to demonstate the effectiveness of the poposed high step-up dc-dc esonant convete.. PROPOSED CONVERTER STRUCTURE The poposed dc-dc high step-up esonant convete topology is shown Fig.1. n this section, convete stuctue and bief opeation of the convete is peseved. The poposed convete consistg of a full bidge netwok, which cludes fou GBT s (S1, S, S3 & S4) and an C paallel esonant tank (, C) and a voltage double convete/ectifie (D1, D) & only one put blockg diode D b. The steady-state opeatg wavefoms of the poposed convete & the divg signals of all ma switches & diffeent modes of opeation wavefoms ae shown fig.. Figue 1. Cicuit topology of the poposed convete 13 (C)Global Jounal Of Engeeg Science And Reseaches
[Naik, 4(9): Septembe 17] SSN 348 834 DO- 1.581/zenodo.9984 mpact Facto- 4. Figue. Opeatg wavefoms of the poposed convete. PRNCPE OF OPERATON The bief desciption and analysis of diffeent modes of opeation ae shown Fig.3. The equied put DC voltage is geneated fom a sola panel and is fed to the DC-DC convete. n this topology, a total of eight diffeent modes of opeations ae pesent fo a switchg peiod T S. Fo the poposed convete, S1 & S4 ae tuned on & off simultaneously; similaly, S & S3 ae tuned on & off simultaneously by givg divg signals. The Pocess of the convete is simplified by the assumptions as listed below; 1) All the powe semiconducto devices/switches ae GBT s, Diodes, Capacitos and nductos ae ideal components. ) The convete is unde steady state opeation. 3) The output capacitos C1& C ae equal & with lage values. So that a switchg peiod of Ts the output voltage V is consideed as constant. a) Mode 1 [t, t 1 ] [see though Fig. 3(a)] n this mode of opeation, S1& S4 ae tuned on and the put voltage V applied acoss the paallel C esonant convete ie. V = V C = V. Dug this mode, the opeation of the convete is simila to a conventional boost convete & the cuent though the esonant ducto is ceases lealy fom m, that ducto is acts as boost ducto. At this condition, load is poweed by C1 & C. Fally at t 1, the eaches to 1. 133 (C)Global Jounal Of Engeeg Science And Reseaches
[Naik, 4(9): Septembe 17] SSN 348 834 DO- 1.581/zenodo.9984 mpact Facto- 4. VT 1 1 m (1) Whee T 1 = time teval between t to t 1. The enegy deliveed to is given by, 1 E ( 1 m ) () b) Mode [t 1, t 3 ] [see though Fig. 3(b)] n this mode of opeation, S1& S4 ae tuned off and then esonates with C. At t 1, stats to cease fom 1 to max and similaly, V C stats to decease fom V to. At t, the V C ceases fom negative diection V C = - V & the stats to decease fom max ie. = max. Also dug this tansition, the voltages acoss switches S1 & S4 each V & the voltages acoss S & S3 falls to zeo. Then these two switches ae tuned on at ZVS. Afte t, S & S3 ae tuned on but no cuent flows though these switches. The anti-paallel diodes of S & S3 ae conduction espectively. Dug this mode of switchg peiod, the powe doesn t tansfe fom souce to load. The total enegy is said to be stoed C paallel esonant tank, ie., 1 1 1 1 V 1 CV C (3) We have V ( t) s[ w ( t t1)] 1 cos[ w ( t t1)] Z (4) V ( t) V cos[ w ( t t1)] 1Z s[ w ( t t1)] C 1 T acs w V V 1 C acs V V 1 C (5) Whee T = time teval between t 1 to t 3. w 1/ C, Z / C 134 (C)Global Jounal Of Engeeg Science And Reseaches
[Naik, 4(9): Septembe 17] SSN 348 834 DO- 1.581/zenodo.9984 mpact Facto- 4. Figue 3. Equivalent cicuits of each mode of opeations stages. (a) [t o, t 1 ]. (b) [t 1, t 3 ]. (c) [ t 3, t 4 ]. (d) [ t 4, t 5 ]. (e) [ t 5, t 6 ]. (f) [t 6, t 8 ]. (g) [ t 8, t 9 ]. (h) [ t 9, t 1 ] c) Mode 3 [t 3, t 4 ] [see though Fig. 3(c)] n this mode of opeation, at t 3, V C = -V / and all switches ae not conduction mode. The diode D1 stats conductg natually, the output capacitance C1 is chaged because of though diode D1 without any change 135 (C)Global Jounal Of Engeeg Science And Reseaches
[Naik, 4(9): Septembe 17] SSN 348 834 DO- 1.581/zenodo.9984 mpact Facto- 4. the V C and lealy deceases and fally eaches to zeo at t 4. The deliveed enegy acoss load this mode of opeation is given by, V T E 3 out 4 (6) Whee T 3 = time teval of t 3 to t 4 T 3 V n half of the switchg peiod, the total consumed enegy is given by, V T E S R (7) et as assumg the convesion efficiency of the convete is 1 % and we can wite the equation fo half of the switchg peiod is, Substitutg the (6), (7) (8), then we have E = E out = E R (8) mt V S (9) V 3 T T S (1) V d) Mode 4 [t 4, t 5 ] [see though Fig. 3(d)] At t 4, = and cuent the diode D1 also deceases to zeo. At this condition, the D1 diode is tuned off with ZCS; and hence thee is no evese ecovey. Afte t 4, esonates with C. Then C stats to dischage though, V C ceases positive diection & ceases negative diection. And fally this mode of opeation at t 5, V C = V & = 3. n this mode of opeation, the stoed enegy the C esonant tank is unchanged, i.e., We have V 3 1 1 1 C C V 3 1 C ( V 4V ) (11) (1) V ( t) s[ w ( t t5 )] w V VC ( t) cos[ w ( t t5 )] 1 V 4 cos T ac w V Whee T 4 = time teval of t 4 to t 5. (13) (14) (15) 136 (C)Global Jounal Of Engeeg Science And Reseaches
[Naik, 4(9): Septembe 17] SSN 348 834 DO- 1.581/zenodo.9984 mpact Facto- 4. e) Mode 5 [t 5, t 6 ] [see Fig. 3(e)] n this mode of opeation, the switches S & S3 ae tuned on and Stats chagg by V though S & S3, ceases negative diection. The modes of opeation fom t 5 to t 1 ae simila to modes of opeations of t to t 5. All the equivalent cicuits of these modes of opeations wee pesented Fig. 3. Dug mode 5 to mode 8, the switches S & S3 ae tuned on and switches S1 &S4 ae tuned off with ZVS and the diode D is tuned off with ZCS condition. V. ANAYSS OF THE CONVERTER n the poposed convete, the put diode can act as a potection device fo souce/put side. t can block the output faults and pevent the fault pass though put side and vice vesa. Fom fig., we have T s (16) By combg (1), () & (1) T T T T V T1 C V V V TS VT 1 Rewitg the above equation ( 4 ) S C ( V 4 V ) 4 V T C ( V 4 V ) T1 V V Fom equation (15), the ga of the convete is given by, 1 3 4 (17) (18) V V cos( w T4 ) Substitute the equation (18) (1) yields, (19) Substitute the equation () (3) yields, 1 ( V S C V T The esonant fequency of the convete is given by, f S 1 C 4V ) 4V T 4 We can obseve that the ga of the poposed convete is affected by the paametes of esonant convetes ( & C ) and the pat of switchg peiod of T 4. That implies, the ga of the convete is impacted by, C and the switchg fequency. V. SMUATON RESUTS The poposed convete cicuit has been simulated usg MATAB softwae. The esults have veified to be acceptable with the theoetical esults. The detailed simulated paametes ae 137 () (1) () (C)Global Jounal Of Engeeg Science And Reseaches
[Naik, 4(9): Septembe 17] SSN 348 834 DO- 1.581/zenodo.9984 mpact Facto- 4. nput voltage, V = 4 V Output voltage, V = 8 V Resonant ductance, = 6µH Resonant capacitance, C =1.68µF Filte capacitance, C 1, C = µf Switchg fequency, f s = 4HZ Figue 4. Expeimental wavefoms of switchg signals and esonant ducto cuent & capacitance voltage with put voltage 4volts Figue 5. Voltages acoss switches and diodes 138 (C)Global Jounal Of Engeeg Science And Reseaches
[Naik, 4(9): Septembe 17] SSN 348 834 DO- 1.581/zenodo.9984 mpact Facto- 4. Figue 6. Output capacitance cuent and voltages V. CONCUSON n this wok, teface usg DC-DC high Step-up non-tansfome esonant convete fo gid connected Nonconventional enegy souces is poposed, which can achieves vey high step-up voltage ga and it is suitable fo high-powe high-voltage applications. The convete utilizes the esonant ducto to delivey powe by chagg fom the put and dischagg to the output. The esonant capacito is employed to achieve zeo-voltage tun-on and tun-off fo the active switches and ZCS fo the ectifie diodes. The analysis demonstates that the convete can opeate at any ga value (>) with pope contol, howeve, the paametes of the esonant tank deteme the maximum switchg fequency, the ange of switchg fequency and cuent atgs of active switches and diodes REFERENCES 1. N. M. Maceod, C. D. Bake, N. M. Kiby, Connection of Renewable Enegy Souces though Gid Constat Pots usg HVDC Powe Tansmission Systems EEE PES T&D 1.. Adian Szabo, Mohan Kansaa, Edwad Stephen Wada, A Geneal Appoach Fo the Study Of Dc-Dc Convetes Poceedg of the 6th ntenational Confeence on optimization of Electical and Electonic Equipment.vol. pp. 35-33, yea 1998. 3. C. Meye, Key components fo futue offshoe DC gids, Ph.D. dissetation, RWTH Aachen Univ., Aachen, Gemany, pp. 9 1, 7. 4. Qun Zhao, Fed C. ee, High-Efficiency, High Step-Up DC DC Convetes, EEE Tansactions On Powe Electonics, Vol. 18, No. 1, Januay 3. 5. D. Jovcic, Bidiectional, high-powe DC tansfome, EEE Tans. Powe Del., vol. 4, no. 4, pp. 76 83, Oct. 9. 6. A. Suganya, D. M. Sudhakaan,, Pefomance Analysis Of High Step-Up Dc-Dc Convete Fo Photovoltaic (Pv) System 15 ntenational Confeence on Cicuit, Powe and Computg Technologies [CCPCT]. 7. N. Punitha, T. Saanya, High Efficiency Fly-Back Convete Usg Resistance Compession Netwok, EEE Sponsoed nd ntenational Confeence on nnovations nfomation Embedded and Communication Systems CECS 15. 8. D. Habumugisha, S. Chowdhuy, S.P Chowdhuy, A DC-DC nteleaved Fowad convete to step - up DC voltage fo DC Mico-gid Applications,13 EEE Powe & Enegy Society geneal meetg. 9. Juaj Koscelnik, Jozef Sedo, Banislav Dobucky, Modelg of Resonant Convete with Nonlea nductance, 14 tenational confeence an Applied Electonics, pp 153-156. 1. A. A. Haga, A new family of tansfome less modula DC-DC convetes fo high powe applications, Ph.D. dissetation, Dept. Elect. Eng., Univ. of Toonto, Toonto, ON, Canada, 11. 11. Wu chen, Xiaogang wu, iangzhong Yao, Wei Jiang, Renjie Hu, A Step-up Resonant Convete fo gid connected Renewable enegy souces, EEE Tansactions on Powe Electonics, vol. 3, No.6, June 15. 139 (C)Global Jounal Of Engeeg Science And Reseaches
[Naik, 4(9): Septembe 17] SSN 348 834 DO- 1.581/zenodo.9984 mpact Facto- 4. 1. Bo-Ren, Jia-Yu Dong, Jyun-Ji Chen, Analysis and mplementation of a ZVS/ZCS DC DC Switchg Convete With Voltage Step-Up, EEE Tansactions On ndustial Electonics, Vol. 58, No. 7, July 11. 13. X. Ruan,. Zhou, and Y. Yan, Soft-switchg PWM thee-level convetes, EEE Tans. Powe Electon., vol. 16, no. 5, pp. 61 6,Sep. 1. 14. Futoshi Nakanishi, Tomoaki kegami, Kenji Ebihaa, Satoshi Kuiyama, Yuuji Shiota, Modelg And Opeation Of A 1okw Photovoltaic Powe Geneato Usg Equivalent Electic Cicuit Method, confeence ecod of twenty eighth EEE photovoltaic specialists confeence, pp.173-176. 15. D. Jovcic, Step-up dc dc convete fo megawatt size applications, ET Powe Electon., vol., no. 6, pp. 675 685, 9. 16. S. Fan, W. Ma, T. C. im, and B. W. Williams, Design and contol of a wd enegy convesion system based on a esonant dc/dc convete, ET Renew. Powe Gene., vol. 7, no. 3, pp. 65 74 14 (C)Global Jounal Of Engeeg Science And Reseaches