Open Access Library Journal 218, Volume 5, e4682 ISSN Online: 2333-9721 ISSN Prin: 2333-975 Simulai Analysis of DC-DC Circui Based Simulink in Inelligen Vehicle erminal Weiran Li, Guoping Yang College of Auomoive Engineering, Shanghai Universiy of Engineering Science, Shanghai, China How o cie his paper: Li, W.R. and Yang, G.P. (218) Simulai Analysis of DC-DC Circui Based Simulink in Inelligen Vehicle erminal. Open Access Library Journal, 5: e4682. hps://doi.org/1.4236/oalib.114682 Received: May 25, 218 Acceped: June 26, 218 Published: June 29, 218 Copyrigh 218 by auhors and Open Access Library Inc. his work is licensed under he Creaive Comms Aribui Inernaial License (CC BY 4.). hp://creaivecomms.org/licenses/by/4./ Open Access Absrac Wih he popularizai of inelligen ransporai sysems, inelligen vehicle erminal has emerged. As he mos imporan par of he Inelligen ransporai Sysem (IS), he smar vehicle-mouned erminal inegraes echnologies such as he Inerne of hings, saellie navigai echnology, and even arificial inelligence, and is now widely used in various modes of ransporai. he oupu volage of auomoive vehicle power supplies is generally 12 V, 24 V, 36 V, while he operaing volage of embedded chips inside vehicle-mouned erminals such as auomobiles or buses generally needs o be depressurized before hey can work normally. herefore, his paper will analyze four basic DC chopper circuis, analyze is working principle, and build a DC-DC circui model according o Malab/Simulink sofware and finally analyze he waveform of he simulai oupu. Subjec Areas Mechanical Engineering Keywords Inelligen Vehicle erminal, DC-DC, Malab/Simulink 1. Inroduci Wih he developmen of power elecrics echnology, DC-DC echnology has been widely used in he indusrial fields of compuers, communicais, auomobiles and aerospace. All cars are powered by DC power supplies. he various elecric compens in he car also use DC power. his is bound o be applied o DC-DC echnology o mee he operaing volage requiremens of various auomoive elecric compens. his paper analyzes he working principle of DOI: 1.4236/oalib.114682 Jun. 29, 218 1 Open Access Library Journal
four DC-DC echnologies, which are DC buck chopper circui, DC boos chopper circui, Buck-Boos chopper circui and Cuk chopper circui. Finally, DC-DC circui model will be buil based Malab/Simulink sofware, and he waveform of he simulai oupu will be analyzed [1]. 2. Buck Chopper Circui 2.1. he Principle of Buck Chopper Circui A ime =, he V driver is urned and he VD is subjeced o back pressure and urned off. he power supply E supplies power o he load, he load volage U = E, and he load curren i rises in an expenial manner (Figure 1). A = 1, V is urned off and he diode VD is freewheeling. he load volage U is approximaely zero, and he load curren decreases expenially (Figure 2, Figure 3). he large inducor L is usually cneced in series so ha he load curren is cinuous and he ripple is small [2]. 2.2. Basic Calculai Relais When he curren is cinuous, he average load volage is: U = E = E = α E + off (2-1) α Duy Raio. he maximum value of U is E, and if α is reduced, U will decrease wih i reducing he chopper circui, also known as he Buck cverer. he average load curren is: I U E m = (2-2) R When he curren is inerruped, he average value of U will be raised and i is generally undesirable [2]. 3. Boos Chopper Circui Assume ha L and C are very large. When he swich is urned, curren flows hrough he inducor and he swich, he diode is reverse biased, and he oupu is isolaed from he inpu. he power supply charges he inducor L. A his ime, he diode VD beween R and L is reverse biased. Due o he csan curren of he inducor L, he charging curren is basically a csan value i L. When VD is urned off, C is discharged o he load RL. Since C is charged and he C capaciy is large, he load volage is mainained a a csan value, and he capacior C is direced o he load. Power supply, he oupu volage U is csan. When he swich is urned off, he polariy of he poenial changes, VD urns o posiive bias, he induced poenial of he inducor urns he diode, he inducor curren i L forms a loop hrough he diode and he load, and he inducor L superposes wih he power supply o charge he capacior C ogeher [3] (Figures 4-7). DOI: 1.4236/oalib.114682 2 Open Access Library Journal
V L R E VD u E M M Figure 1. he principle diagram of he circui. u GE i off u E Figure 2. he curren cinues. u GE off i u E E Figure 3. he curren inerrups. L VD i i 1 E V C u R Figure 4. he principle diagram of he circui. 4. Boos and Buck Chopper Circui 4.1. he Principle of Buck Chopper Circui Assume ha he L value is large and he C value is also large (Figure 8). he DOI: 1.4236/oalib.114682 3 Open Access Library Journal
u GE i Figure 5. Volage and curren Waveform. Figure 6. Cinuous curren. Figure 7. Insufficien curren. inducor curren 1 i and he capacior volage, i.e., he load volage U, are basically csan. here are wo modes [3]: DOI: 1.4236/oalib.114682 4 Open Access Library Journal
S id VD i U d L i L u C R S g off i L U L U d U Figure 8. Boos and Buck chopper circui and is waveform. 1) When S is, he power supply U supplies power o he L via S, and he curren is 1 i. A he same ime, C mainains he oupu volage csan and supplies power o he load R. 2) When S is off, he energy of L is released o he load, and he curren is 2 i. he polariy of he load volage is posiive and negaive, and he polariy of he power supply volage is reversed. his circui is also referred o as a reverse polariy chopper circui. 4.2. Basic Calculai Relais In seady sae, he inegral of he volage U L in a period is zero: ud L = (4-1) When V is in he sae, U L = E; and when S is in he off sae, U L = U. hen: Oupu volage: E = U (4-2) α U = E = E = E 1 α off off (4-3) By changing α, he oupu volage can be eiher higher han he supply volage or lower han he supply volage. When < α < 1/2, he oupu volage is lower han he supply volage, and when 1/2 < α < 1, he oupu volage is higher han he supply volage. herefore, i is called a buck-boos chopper circui or a buck-boos cverer [2]. DOI: 1.4236/oalib.114682 5 Open Access Library Journal
5. Cuk Chopper Circui 5.1. he Principle of Cuk Chopper Circui (Figure 9, Figure 1) L1 C L2 E V VD u R Figure 9. he principle diagram of he circui. Figure 1. Equivalen circui. 5.2. Basic Calculai Relais In he seady sae, he inegral of he curren of he capacior C in e cycle is zero, ha is: id c = (5-1) In he equivalen circui, he ime for he S poin o cnec o he B poin is, So he produc of capaciance curren and ime is I 2 *. he ime for S o cnec A poin is off, so he produc of capaciance curren and ime is I 1 * off. As a resul, i can be obained: I = I (5-2) 2 1 off When he capaciance C is very srg, he capaciance volage U C pulsai is sufficienly small, and he relaiship beween he oupu volage U and he inpu volage E can be calculaed as follows [4]: When he S poin is cneced o B poin, B poin volage U B =, A poin volage U A = U C ; DOI: 1.4236/oalib.114682 6 Open Access Library Journal
When he S poin is cneced o A poin, U B = U C, U A =. herefore, he average value of U B is [3]: U B off = UC (5-3) off E = UB = UC (5-4) In addii, he average volage of he volage of he A poin is: U U A = UC (5-5) = UC (5-6) hen we can ge he relaiship beween he oupu volage U and he power supply volage E: α U = E = E = E 1 α 6. Simulink Circui Simulai Analysis off (5-7) According o he above principle, he simulai models are esablished by using he power elecric module library in MALAB/SIMULINK sofware, and he correspding parameer is se o simulae he waveform diagram. 6.1. Buck Chopper Circui Simulai Parameer seings: Cycle:.5 s; Duy cycle: 2%, 5%; Durai:.5 s; Supply volage VDc: 12 V; Inducance L:.45H; Load resisance R: 1 Ω; Capaciance C:.26F; Algorihm: ode45. he simulai diagram of he buck chopper circui is shown in Figures 11-13 respecively represen he simulai waveforms wih duy cycles of 2% and 5%. he waveforms in Figure 12 and Figure 13 are represened from op o boom as follows: pulse waveform, load volage U R, inducor volage U L, inducor curren I L, hyrisor curren, and supply curren. By analyzing he waveform diagram, i can be seen ha he simulai waveform is csisen wih he heoreical analysis [5]. 6.2. Boos Chopper Circui Simulai Parameer seings: Cycle:.1 s; Duy cycle: 2%, 5%; Durai:.1 s; Supply volage VDc: 12 V; Inducance L:.1H; Load resisance R: 1 Ω; Capaciance C:.26F; Algorihm: ode 23. he simulai diagram of he boos chopper circui is shown in Figure 11-13 respecively represen he simulai waveforms wih duy cycles of 2% and 5%. he waveforms in Figures 14-16 are represened from op o boom as follows: pulse waveform, load volage U R, inducor volage U L, inducor curren DOI: 1.4236/oalib.114682 7 Open Access Library Journal
Figure 11. Buck chopper circui simulai. Figure 12. Duy cycle 2%. Figure 13. Duy cycle 5%. DOI: 1.4236/oalib.114682 8 Open Access Library Journal
Figure 14. Boos chopper circui simulai. Figure 15. Duy cycle 2%. Figure 16. Duy cycle 5%. DOI: 1.4236/oalib.114682 9 Open Access Library Journal
Figure 17. Boos and Buckchopper circui simulai. Figure 18. Duy cycle 2%. Figure 19. Duy cycle 8%. DOI: 1.4236/oalib.114682 1 Open Access Library Journal
Figure 2. Cuk chopper circui simulai. Figure 21. Duy cycle 2%. Figure 22. Duy cycle 8%. DOI: 1.4236/oalib.114682 11 Open Access Library Journal
I L, hyrisor curren, and supply curren. By analyzing he waveform diagram, i can be seen ha he simulai waveform is csisen wih he heoreical analysis. 6.3. Boos and Buck Chopper Circui Parameer seings: Cycle:.1 s; Duy cycle: 2%, 8%; Durai:.2 s; Supply volage VDc: 12V; Inducance L: 5e 3; Load resisance R: 5 Ω; Capaciance C: 5e 5; Algorihm: ode45. he simulai diagram of he boos and buck chopper circui is shown in Figures 17-19 respecively represen he simulai waveforms wih duy cycles of 2% and 8%. he waveforms in Figure 18 and Figure 19 are represened from op o boom as follows: pulse waveform, inpu curren, oupu curren, oupu volage. By analyzing he waveform diagram, i can be seen ha he simulai waveform is csisen wih he heoreical analysis. 6.4. Cuk Chopper Circui (Figure 2) Parameer seings: Cycle:.1 s; Duy cycle: 2%, 8%; Durai:.2 s; Supply volage VDc: 12V; Inducance L:.8H; Load resisance R: 5 Ω; Capaciance C: 1e 5; Algorihm: ode45. he simulai diagram of he Cuk chopper circui is shown in Figures 2-22 respecively represen he simulai waveforms wih duy cycles of 2% and 8%. he waveforms in Figures 2-22 are represened from op o boom as follows: pulse waveform, inpu curren, oupu curren, oupu volage. By analyzing he waveform diagram, i can be seen ha he simulai waveform is csisen wih he heoreical analysis. 7. Cclusi In his paper, he working principles of Buck chopper circui, Boos chopper circui, Buck and Boos chopper circui, Cuk chopper circui are analyzed, and he Malab/Simulink sofware is used o se up he DC chopper circui model. he resuls show ha he simulai waveform is csisen wih he resuls obained by he cvenial analysis mehod, and he four DC chopper circuis can well accomplish he boos and decompressi. hrough he simulai of hese four kinds of circuis, we can see ha hese circuis can effecively and seadily sep down he 12V DC power supply, and ulimaely provide power for various elecrical compens in he vehicle erminal. References [1] Wei, L.M. and Lu, X.Y. (216) A Sudy DC Chopping Circuis Based MALAB. Journal of Jilin Engineering Normal Universiy, No. 3, 87-89. [2] Li, Y.Y., Wang, Y.J. and Zhang, L.P. (214) Modern Power Elecrics echnology. DOI: 1.4236/oalib.114682 12 Open Access Library Journal
4h Edii, singhua Universiy Press, Beijing. [3] Wang, Y.L. (213) Modern Power Elecrics. 3h Edii, Elecric Indusry Press, Beijing. [4] Zhao, L.B. (26) Modern Elecric Power Base. 3h Edii, singhua Universiy Press, Beijing. [5] Chen, B.S. (25) Elecric Drive Auomaic Crol Sysem, Moi Crol Sysem. 3h Edii, Machinery Indusry Press, Beijing. DOI: 1.4236/oalib.114682 13 Open Access Library Journal