IJSRD - International Journal for Scientific Research & Development Vol. 6, Issue 03, 2018 ISSN (online):

Transcription

1 IJSRD - International Journal for Scientific Research & Development Vol. 6, Issue 03, 2018 ISSN (online): Direct Duty Ratio Control of Boost Converter for Asymmetrical Variable Step Size Incremental Conductance Maximum Power Point Tracking Method for Shilpa 1 Neha Gupta 2 1,2 Om Institute Technology & Management, Juglan, Hisar, India Abstract In this paper, utilization of a boost converter for control of photovoltaic power using Maximum Power Point Tracking (MPPT) control mechanism is presented. First the photovoltaic module is analyzed using SIMULINK software. For the main aim of the project the boost converter is to be used along with a Maximum Power Point Tracking control mechanism. The MPPT is responsible for extracting the maximum possible power from the photovoltaic and feed it to the load via the boost converter which steps up the voltage to required magnitude. The main aim will be to track the maximum power point of the photovoltaic module so that the maximum possible power can be extracted from the photovoltaic. The algorithms utilized for MPPT are generalized algorithms and are easy to model or use as a code. The algorithms are written in m files of MATLAB and utilized in simulation. Both the boost converter and the solar cell are modeled using Sim Power Systems blocks. Key words: Photovoltaic Cell, Boost Converter, MPPT, Inverter and Battery, Solar Energy I. INTRODUCTION Solar energy is radiant light and heat from the Sun that is harnessed using a range of ever evolving technologies such as solar heating, photovoltaic, solar thermal energy, solar architecture, molten salt power plants and artificial photosynthesis It is an important source of renewable energy and its technologies are broadly characterized as either passive solar or active solar depending on how they capture and distribute solar energy or convert it into solar power. Active solar techniques include the use of photovoltaic systems, concentrated solar power and solar water heating to harness the energy. One of the major concerns in the power sector is the day-to-day increasing power demand but the unavailability of enough resources to meet the power demand using the conventional energy sources [20]. Demand has increased for renewable sources of energy to be utilized along with conventional systems to meet the energy demand. Renewable sources like wind energy and solar energy are the prime energy sources which are being utilized in this regard. The continuous use of fossil fuels has caused the fossil fuel deposit to be reduced and has drastically affected the environment depleting the biosphere and cumulatively adding to global warming. Solar energy is abundantly available that has made it possible to harvest it and utilize it properly. Solar energy can be a standalone generating unit or can be a grid connected generating unit depending on the availability of a grid nearby [21]. Thus it can be used to power rural areas where the availability of grids is very low. Another advantage of using solar energy is the portable operation whenever wherever necessary. In order to tackle the present energy crisis, one has to develop an efficient manner in which power has to be extracted from the incoming solar radiation [22-24]. The power conversion mechanisms have been greatly reduced in size in the past few years. The development in power electronics and material science has helped engineers to come up very small but powerful systems to withstand the high-power demand. But the disadvantage of these systems is the increased power density. Trend has set in for the use of multi-input converter units that can effectively handle the voltage fluctuations. But due to high production cost and the low efficiency of these systems they can hardly compete in the competitive markets as a prime power generation source. The constant increase in the development of the solar cells manufacturing technology would definitely make the use of these technologies possible on a wider basis than what the scenario is 3 presently. The use of the newest power control mechanisms called the Maximum Power Point Tracking (MPPT) algorithms has led to the increase in the efficiency of operation of the solar modules and thus is effective in the field of utilization of renewable sources of energy. II. RELATED WORK Some of the recent workings related to the research paper is described below, The topic of solar energy utilization has been looked upon by many researchers all around the globe. It has been known that solar cell operates at very low efficiency and thus a better control mechanism is required to increase the efficiency of the solar cell. In this field researchers have developed what are now called the Maximum Power Point Tracking (MPPT) algorithms. Mummadi Veerachary has given a detailed report on the use of a SEPIC converter in the field of photovoltaic power control. In his report he utilized a two-input converter for accomplishing the maximum power extraction from the solar cell [3]. M. G. Villalva in his both reports has presented a comprehensive method to model a solar cell using Simulink or by writing a code. His results are quite similar to the nature of the solar cell output plots [1]-[2]. P. S. Revankar has even included the variation of sun s inclination to track down the maximum possible power from the incoming solar radiations. The control mechanism alters the position of the panel such that the incoming solar radiations are always perpendicular to the panels [9]. M. Berrera has compared seven different algorithms for maximum power point tracking using two different solar irradiation functions to depict the variation of the output power in both cases using the MPPT algorithms and optimized MPPT algorithms [8]. All rights reserved by 374

2 Ramos Hernanz has successfully depicted the modeling of a solar cell and the variation of the currentvoltage curve and the power-voltage curve due the solar irradiation changes and the change in ambient temperature [10]. Marcelo Gradella Villalva, Jonas Rafael Gazoli, Ernesto Ruppert Filho.This paper presents an easy and accurate method of modeling photovoltaic arrays. The method is used to obtain the parameters of the array model using information from the datasheet. The photovoltaic array model can be simulated with any circuit simulator. The equations of the model are presented in details and the model is validated with experimental data. Finally, simulation examples are presented. This paper is useful for power electronics designers and researchers who need an effective and straightforward way to model and simulate photovoltaic arrays. III. MODELLING OF PHOTOVOLTAIC CELL A solar cell is the building block of a solar panel. A photovoltaic module is formed by connecting many solar cells in series and parallel. Considering only a single solar cell; it can be modeled by utilizing a current source, a diode and two resistors. This model is known as a single diode model of solar cell. Two diode models are also available but only single diode model is considered here [1], [2], [4], [7], [9] and [10]. Mode 1-The operating condition of the boost converter is depending on the duty cycle of the switching frequency, if the switch is closed (ON), battery provides the charging current to the inductor and inductor is fully charged. There is no current flowing through the diode cause of capacitor polarity and so that load current remains constant which is being supplied due to the discharging of the capacitor [13]. Mode 2- In the operation of second mode the switch is disconnecting (off), the diode is becomes forward bias. The capacitor will charged through the energy released by inductor. The load current remains constant in the operation of boost converter [13]. V. MODELING OF PHOTOVOLTAIC SYSTEM In this section the architecture of photovoltaic system is shown in Fig.3. A single phase inverter and boost converter using modelling. The panel output is given to the boost converter after boosting the voltage is connected to invert and then supply to load. In this MPPT algorithm switching pulse generated and given to the boost converter for varying the duty cycle of the boost converter. The interfacing with renewable energy sources is also possible for different solar panels can be feed to the inverter as a dc source [8]. The power coming from battery backup is given to inverter through a bi-directional dc-dc converter; the controlled flow of electrical power in either direction is possible by varying duty cycle. Fig. 1: Single diode model of a solar cell The characteristic equation for a photovoltaic cell is given by [1], [2], [4], [7], [9] and [10], IV. BOOST CONVERTER Basically, dc-dc boost converter is mostly used in nowadays for many industrial applications, which a variable dc supply needed. In solar application dc-dc boost converter use for boosting the output voltage of solar panel for varying in the input side resistance of solar panel compare with the load side resistance by changing the duty cycle a boost converter [11]. A boost converter is use for this work, it misses out the maximum tracking point, our system either for trying to other application such as water pumping system which operate on 230 V, so we use a boost converter [12]. i L(t) R L 2 Fig. 3: Block Diagram of MPPT Techniques based Photovoltaic System A. Maximum Power Point Tracking In this modeling our implementation of Maximum power point tracking techniques (MPPT) is used to achieve the maximum power from Photovoltaic system. The Simulink model shows in Fig.4. Vg + - V L(t) 1 i c(t) C R + V(t) - Fig. 2: Power Circuit of Boost Converter Fig. 4: Simulink model of MPPT All rights reserved by 375

3 C. Photovoltaic Modeling Fig. 5: MPPT output B. Inverter It is IGBT use as switch connected with an uncontrolled diode in anti-parallel manner. IGBT is able to current conducting in both directions. In which switches junction point in one leg of inverter represent output point for the connected load to the system [25]. In simulation of half bridge inverter, load connected to mid-point of the input dc source and juncture point of the both switches of inverter shows in Fig.6 If assumed that input side voltage of inverter is constant and both switches have no loss. The concept of half bridge, input voltage is divided in two equally parts with help of a loss free capacitive potential divider. The electronics switch is connected to Each legs of inverter within dotted lines in the Fig. Sw1, Sw2 on then output voltage will be +Vs and when Sw3 and Sw4 are on output voltage will be -Vs. Fig. 8: Photovoltaic modeling Fig. 9: Solar Panel Output D. Boost Converter Modeling Fig. 6: Simulink model of Inverter Three Phase Fig. 10: Boost Converter Modeling E. Complete Simulink of MPPT Techniques based on photovoltaic system with Boost converter Fig. 7: Three Phase Waveform of Inverter Fig. 11: Complete Simulink of MPPT Techniques based photovoltaic system All rights reserved by 376

4 Fig. 13: Waveforms representation of solar panel without using boost converter Fig. 12: Waveform representation of the solar panel using boost converter VI. MODEL WITHOUT BOOST CONVERTER Fig. 13: Simulink Model of solar panel without using boost converter A. Compared Result without Boost converter VII. CONCLUSION P-V, I-V curves can be obtained from the simulation of the PV array designed at completely different irradiation levels and temperatures but here we have shown the output by taking irradiation level at 60. The proposed system has been designed in MATLB SIMULINK. However, the performance of the photovoltaic system depends on the spectral distribution of the solar radiation. Hence, Boost converter is used to improve the PV output power & MPPT methods are used to increase PV system efficiency. There are various types of MPPT methods. The Modified asymmetric variable step Incremental Conductance method is more efficient in compared to all other MPPT methods because panel terminal voltage is changed according to its value relative to the MPP voltage & offers good performance under quickly changing atmospheric conditions. It can also be seen by the outputs of both the Simulink models (one is without boost converter & other is with boost converter) that the output voltage as well as output power is increasing by using boost converter. Therefore, it is seen that by using the Incremental Conductance MPPT technique efficiency of the photovoltaic system with boost converter is increased. REFERENCES [1] Nicola Femia, Giovanni Petrone, Giovanni Spagnuolo, Massimo Vitelli, Optimization of Perturb and Observe Maximum Power Point Tracking Method,International Conference on Recent Trends in Applied Sciences with Engineering Applications 4, JULY 2005, pp [2] AlivaraniMohapatra, ByamakeshNayak, BanishreeMisra. Model Validation and Maximum Power Point Tracking of Photovoltaic Module.International Conferenceon Renewable Energy and Sustainable Energy,1994, Pp [3] Hardik P. Desai, and H. K. Patel", Maximum Power Point Algorithm in PVGeneration: An Overview IEEE Research 2009,pp Dalila BERIBER LINS Laboratory, MPPT Techniques for PV Systems. All rights reserved by 377

5 University of Sciences and Technology HouariBoumediene, 2013.pp [4] Ajay Patel Rajiv Gandhi ProudyogikiVishwavidyalaya, University, Bhopal Oriental Institute of Science & Technology, Bhopal, Perturb and Observe Maximum Power Point Tracking for Photovoltaic Cell pp IoanViorelBanu, Marcel Istrate Gheorghe Asachi Technical University of Iasi Modeling of Maximum Power Point Tracking Algorithm for Photovoltaic Systems 2008 [5] Gergaud O, Multon B, Ben Ahmed H. Analysis and experimental validation of various photovoltaic system models. 7th International ELECTRIMACS Congress, Montréal, Canada, 2002, pp [6] Esram T, Chapman P.L. Comparison of photovoltaic array maximum power point tracking techniques. IEEE Trans. Energy Conversion, 2007; 22: [7] Tafticht T, Agbossou K, Doumbia ML, Chériti A. An improved maximum power point tracking method for photovoltaic systems. Renewable Energy, 2008; 33: [8] Veerachary M, Senjyu T, Uezato K. Neural-networkbased maximum power-point tracking of coupledinductor interleaved-boostconvertersupplied PV system using fuzzy controller. IEEE Trans. Ind. Electron, 2003; 50: [9] Enrique JM, Duràn E, Sidrach-de-Cardona M, Andùjar JM. Theoretical assessment of the maximum power point tracking efficiency of photovoltaic facilities with different converter topologies. Solar Energy,2007; 81: [10] Femia N, Petrone G, Spagnolo G, Vitelli M. Optimization of Perturb and Observe Maximum Power Point Tracking Method. IEEE Trans. Power Electron., 2005; 20: [11] PoornimaMazumdar, Prasad N. Enjeti, Robert S. Balog Electrical and Computer Engineering, Texas A&M University Analysis and Design of Smart PV Modules 2013, pp [12] R. Ramaprabha, B. L. Mathur, MATLAB based modelling to study the influence of shading on series connected SPVA, 2nd International Conference on Emerging Trends in Engineering and Technology, pp , Dec [13] Marcelo G, Gazoli J. and Filho E., Comprehensive Approach to Modeling and Simulation of Photovoltaic Arrays, IEEE Transactions On Power Electronics, vol. 24, no. 5, May 2009, p.p [14] HairulNissahZainudin, SaadMekhilef Comparison Study of Maximum Power Point Tracker Techniques for PV Systems Proceedings of the 14th, International Middle East Power Systems Conference (MEPCON 10), Cairo University, Egypt, December 19-21, [15] S. Ali Khajehoddin, Praveen Jain, and AlirezaBakhshai, Cascaded Multilevel Converters and Their Applications in Photovoltaic Systems, 2nd Canadian Solar Buildings Conference Calgary, June 10-14, [16] M. Thiagarajan, P.Pavunraj, Multilevel Inverter For PV System Employing MPPT Technique, International Journal of Engineering Research & Technology (IJERT), Vol. 1 Issue 5, July [17] Yue Cao, L.M. Tolbert, Multilevel DC-AC Converter Interfaced with Solar Panels, Journal of Undergraduate Research at the University of Tennessee, Vol 1,2010. [18] MouloudA.Denai, Frank Palis, AbdelhafidZeghbeb, ANFIS Based Modelling and Control of Non-Linear Systems: A Tutorial, IEEE International Conference on Systems, Man and Cybernetics, [19] J. S. R. Jang, ANFIS: Adaptive Network-Based-Fuzzy Inference System, IEEE Transactions On Systems, Man And Cybernetics, VOL. 23, NO. 3,MAY/JUNE,1993 [20] Carlo Cecati, FabrizioCiancetta, A Multilevel Inverter for Renewables with Fuzzy Logic-based Control, IEEE Conference Publication, International Conference on Clean Electrical Power, 9-11 June 2009, Page(s): [21] L.G. Franquelo, J. Rodriguez, J. I. Leon, S. Kouko, R. Portillo, M. A.M. Prats, The Age Of Multilevel Converters Arrives, IEEE Industrial Electronics Magazine, JUNE 2008, PP [22] L.M. Tolbert, F. Z. Peng, T. G. Habetler, Multilevel Converters for Large Electric Drives, IEEE Transactions on Industry Applications, vol. 35, no. 1, Jan./Feb. 1999, pp [23] J. Rodriguez, J. S. Lai, and F. Z. Peng, Multilevel Inverters: Survey of Topologies, Controls, and Applications, IEEE Transactions on Industry Applications, vol. 49, no. 4, Aug. 2002, pp [24] Sudha Letha, Shimi, Tilak Thakur, and Jagdish Kumar. "Harmonic Elimination in a Solar Powered Cascaded Multilevel Inverter Using Genetic Algorithm and Differential Evolution Optimization Techniques", Volume 6B Energy, [25] Karanjkar, D. S., S. Chatterji, Shimi S. L., and Amod Kumar. "Real time simulation and analysis of maximum power point tracking\(mppt) techniques for solar photovoltaic system", 2014 Recent Advances in Engineering and Computational Sciences (RAECS), All rights reserved by 378