Scientific Journal of Impact Factor (SJIF): 4.72 International Journal of Advance Engineering and Research Development Volume 4, Issue 11, November -2017 Electricity generation with the hybrid power generation system Srinivas Kunta 1 Faculty in KU College of Engineering & Technology, Dept. of Electrical & Electronics, KU campus,warangal. cnuchinnu.kunta@gmail.com e-issn (O): 2348-4470 p-issn (P): 2348-6406 ABSTRACT: In this study, the electric energy required for feeding of small power receivers at two laboratories of KU college of Engineering and Technology, Department of Electrical and Electronics is met by hybrid wind-solar power generation system. For this purpose, 600 W 3-phase permanent magnet synchronous generator (PMSG) based wind power generation system (WPGS) and solar power generation system (SPGS) consisting of 190W 3 pieces mono crystal solar panel are combined to build a 1170W wind-solar hybrid power generation system. Besides, to accumulate the consumption excess electric energy or lack of generation, to ensure energy continuity via renewable power system, 100 Ah 12V 6 pieces gel jeep cycle accumulator groups are installed on the wind-solar hybrid power generation system (WSPGS). Then, the block diagrams of the system elements forming the hybrid power generation system and SimPowerSystems in the Matlab/Simulink are used to realize the simulation of the wind-solar hybrid power generation system with battery support. When the curves obtained from the simulation results are examined, it is determined that the electrical and mechanical magnitudes in parallel to the dynamic behavior of the installed hybrid power generation system are so similar. Keywords: Hybrid power generation, Wind Power Generation System (WPGS), Solar Power Generation System (SPGS), Power Flow Control with Battery Support, Simulation, Matlab/Simulink. I. INTRODUCTION It is known that electric energy, one of the consumption tools of today, is being increasingly required by all the countries in all their activity environments. Besides, the quantity of production and consumption of energy and its environmental and efficiency qualities are among the elements that contribute to development levels of countries [1]. Energy need of the world have been covered mostly from fossil base fuels so for. For this reason, countries are highly depended on these fuels. However, as fossil base sources have negative impacts on environment, their reserves are about to be consumed and they increase the dependency of countries on foreign countries, new energy sources are tried to be found. Within this process, the most important researches are made on renewable energy sources that do not have negative impacts on the environment [2]. In general, renewable energy sources consist of wind and solar energies as well as non-fossil base energy sources such as hydroelectric, geothermal, biomass (wood, solid wastes, ethanol, etc) tide. Hydroelectric and wind energy constitute the biggest share in renewable energy sources. Though the shares of wind and solar energies in electric generation are very low, it is expected that these shares will increase in the future. However, the wind turbine and solar cell have been used as hybrid together or separately for electric generation since 1970 s, generally in areas far from the electric network lines. Electric generation with wind turbine or solar cell have some hindrances. The most important hindrances include the facts that the generated energy is interrupted, the initial installation costs are high and there exists no sufficient technological knowledge [3, 4]. While electricity from sun can only be generated in daytime the load remains without energy during the rest of day. Though there is not such a definite limitation in the wind energy, at some hours of a day, electricity can be generated but at other hours, it is impossible to do so. This interruption may be removed by storing the generated energy in the battery when the consumption is low and feeding the load from the battery when the generation is insufficient. The electric energy to be generated from the sun and wind changes depending on seasons. In winter season, it may not be possible to generate electricity from the sun for days. In the same way, in spring and summer months, electric generation from the wind remains at very low levels [5, 6]. Solving the seasonal electricity generation interruption problem through increasing of battery capacity will both increase the cost and is not possible in most places. Depending on characteristics of the region where the @IJAERD-2017, All rights Reserved 1186
installation will be made, the wind tribune and solar panel can be used together to install a hybrid electric generation system so that these interruptions can be removed substantially [7]. In recent years, the hybrid systems are being installed in more than 2 structures. These are installed by combining mainly wind and solar generation systems and diesel, fuel cell, etc electricity generation systems in different structures. However, in hybrid electric generation systems that are installed by more than one renewable energy sources, as more workmen will be used, its cost will increase and the structure and control of the system will become more complicated [8]. By considering the above stated reasons, 1170W wind-solar hybrid power generation system with battery support was installed to feed the small power receivers at two electric laboratories of KU college of Engineering and Technology, Department of Electrical and Electronics. The block diagrams of system components from the hybrid power generation system and SimPowerSystems in the Matlab/Simulink were used to obtain the simulation block schemas. The data from the real system and that from the simulation study are compared to make the accuracy analysis of the simulation study related to the hybrid power generation system. II. WIND-SOLAR HYBRID POWER GENERATION SYSTEM WITH BATTERY SUPPORT AND ITS MODELLING The hybrid power generation systems are the power generation systems that are established by parallel connection of two or more traditional or renewable power generation systems. The hybrid power generation systems are the best solution methods to meet the electric energy needs of mini networks and small settlements far from energy generation and distribution centers. The wind-solar hybrid power generation system is the most commonly used system [9, 10]. Figure 1. General view of the wind-solar hybrid power generation system with battery support General view of the installed wind-solar hybrid power generation system with battery support is given in Fig.1. The installed hybrid power generation system consists of 600W wind tribune, 190W 3 pieces solar panels, a battery group and 1200W hybrid charge control unit that ensures congruent operation of these units and 3kW full sinus wave inverter for consumers fed with alternative current. Besides, data related the energy generated at the hybrid power generation system can be followed via charge control unit in 10 sec intervals. Being followed via computer with the WinPowerNet interface program, they can also be saved as Microsoft Excel file. As it can be seen Fig.2, dynamic modeling of the hybrid power generation system in conformity with its behavior in real time was realized by using the SimPowerSystems in the Matlab/Simulink program. Then, output voltage of WPGS was regulated with AC-DC power converter and output voltage of SPGS with DC-DC power converter to DC 24V and connected to DC bar parallel including the battery group, and hybrid power generation system was established. @IJAERD-2017, All rights Reserved 1187
Figure 2. Simulation block diagram of wind-solar hybrid power generation system with battery support III. WIND POWER GENERATION SYSTEM The wind turbines convert kinetic energy of wind into electric energy. The generated electric energy changes proportionally depending on the speed of wind. In selecting the place of wind turbine, many factors are important. Most important one is the wind speed of the place which must be continuous and high. Besides, elevations that prevent air flow must not exist around the turbine. The simple operation of a wind turbine is as follows; when the air hits on the turbine wings, it causes their turn and so does mill connected to them. In small power wind turbines, this mill is generally connected directly to the generator and in big power wind turbines, to the generator generally by means of gear box. Generators convert this mechanical energy to the electric energy. While in low power wind turbines, mostly permanent magnet generators are used, in high power turbines, synchronous and asynchronous generators are used [11]. The wind turbines are generally produced with 2 or 3 wings or rarely with 1 or more than 3 wings. In this study, the PMSG wind turbine used WPGS is with 3 wings and has 600W 36 VAC output values. The model of wind power generation system is given in Fig.3. Figure 3. The simulation diagram of constant speed PMSG wind power generation system @IJAERD-2017, All rights Reserved 1188
IV. SOLAR POWER GENERATION SYSTEM The sun panels convert the sun light into direct current electric energy. The important thing in the electric generation is presence of light. The operation costs of this generation system are very low and its reliability is very high. By today s technology, from a few watts to 300W in various sizes solar panels are produced. The biggest disadvantage of solar cells is their high cost. The use periods of solar cells vary between 10-25 years depending on their producing technologies [12]. In Fig.4, the simulation block diagram of solar power generation system is given. Figure 4. The simulation diagram of solar power generation system V. HYBRID CHARGE CONTROL UNIT Energies from the wind and solar power generation systems are arranged in the micro processor base hybrid charge control unit. Electric energy comes from both PMSG wind power generation system and solar panels to the control panel when the weather is sunny and windy. When the weather is only sunny or windy, it comes from the respective source. This is completely depends on whether the weather is sunny or windy during operation. Besides, in the PM generator of wind turbine, a 3-phase alternative voltage is generated and in the solar panel, a direct current is generated. To connect these two systems in parallel, their energy forms and magnitudes must be the same. This is ensured by the hybrid charge control unit whose connection schema is given in Fig.5. The wind-solar hybrid charge controller is control device which can control wind turbine and solar panel at the same time and transform wind and solar energy into electricity for the DC load use, with excess energy stored into batteries. Wind-solar hybrid charge controller is the most important part in off-grid system, whose performance has much effect on life expectancy and operation of the whole system, especially the battery expectancy. In this proposed study, there are 10 sockets on the hybrid charge control unit: 2 for the battery group, 3 for the wind turbine generator, 2 for solar panels and 3 for DC load outputs. Figure 5. The connection schema of the installed hybrid power generation system charge control unit @IJAERD-2017, All rights Reserved 1189
The simulation block diagram that reflects the functions, characteristics, and properties of the hybrid charge control unit as in the real time is given in Fig.6. Figure 6. Simulation Diagram of Hybrid Charge Controller VI. POWER FLOW CONTROL AND SIMULATION RESULTS The simulation results of generation and consumption powers of 1170W hybrid power generation system whose installation and simulation was made according to various loading conditions were given separately and analyzed. As it can be understood from Table 1, in the first loading situations, maximum input values were applied to the wind-solar hybrid power generation system and in the full power generation (1170W), it was considered that the battery group was in full charge mode, and by connecting receivers in different powers to the system alternatively, dynamic behavior of electrical magnitudes related to the hybrid power generation system powers were observed. TABLE I. WSPGS loading parameters Wind Power System Solar Power system Battery Group Load Loading situation Wind Pitch Speed Angel (m/s) (deg) Current Insolation SOC Power (A) (%) (W) 1.Loading situation 12 0 5.12 1000 95 480 2. Loading situation 12 0 5.12 1000 95 1050 3. Loading situation 12 0 5.12 1000 95 1550 4. Loading situation 9 0 5.12 950 95 1550 The charge control unit switching positions according to system loading and battery charge situations are given in Table 2. @IJAERD-2017, All rights Reserved 1190
TABLE II. Hybrid charge control unit simulation block diagram switching positions. S. No Swicth Control Rules S 1 S 2 S 3 S 4 S 5 S 6 1 SOC % 95 0 1 0 0 1 1 P Load > ( P Wind + P Solar + P Battery ) 2 SOC < % 95 1 0 0 0 1 1 P Load > ( P Wind + P Solar + P Battery ) 3 SOC % 95 P Load > ( P Wind + P Solar ) and 1 0 1 0 1 1 P Load ( P Wind + P Solar + P Battery ) 4 SOC < % 95 P Load > ( P Wind + P Solar ) and 1 0 0 0 1 1 P Load ( P Wind + P Solar + P Battery ) 5 SOC % 95 1 0 1 1 0 1 P Load ( P Wind + P Solar ) SOC<% 95 6 P Load ( P Wind + P Solar ) 1 0 0 0 1 1 Figure 7. The first loading situation power change curves Figure 8.The second loading situation power change curves Figure 9.The third loading situation power change curves @IJAERD-2017, All rights Reserved 1191
Figure 10.The fourth loading situation power change curves In the first loading situation, a receiver in 480W power was connected to the system. As the drawn power is smaller than the total generated power and the battery group is in full charge mode in this loading situation, the hybrid charge controller deactivates the battery group. Because, the consumer may be fed from the hybrid power generation system without battery support. Besides, consumption power is smaller than the individual generation power capacities of generation units (wind-solar). For this reason, it must itself feed the power required by the consumer as it may be met by a generation system with lower power. As a matter of fact, as it can be understood from the simulation results given in Fig. 7, the solar power generation system that has a lower generation power feeds the receiver. In the second loading situation, a receiver in 1050W power was connected to the system. Also, in this loading situation, as the consumption power is smaller than the total generated power and the battery group is in full charge situation, the hybrid charge controller deactivates the battery group. However, in this loading situation, the drawn power is bigger than the individual generation power capacities of generation units (windsolar). For this reason, the power requirement of the consumer must be met by running the wind-solar power generation unit together. As it can be understood from the simulation results given in Fig. 8, the consumer is fed by hybrid power generation system. 570W of the power drawn by the receiver is met by the power generation system and 480W of it by the wind generation system. In the third loading situation, by increasing the consumer load, 1550W loading was made to the system. As the drawn power is bigger than the total generated power in this loading situation, generation power of the hybrid power generation system will be insufficient. In this situation, the required power must be supported via battery group. When the simulation results are examined in Fig. 9, the battery group is activated by the hybrid charge controller. In this way, the consumer is fed from the hybrid power generation with battery support. 1170W of the power drawn by the consumer is provided from the hybrid power generation system and 380w from battery group; 600W as the wind power generation system and 570W as the solar power generation system. In the fourth loading situation, the wind speed of system in the third loading situation was decreased to 9m/s and solar radiation level to 950 to observe the reaction of system. When the wind speed decreases, the power of wind power generation system must decrease and when the radiation level decreases, the power of solar power generation system must decrease. In that case, the total generated power will fall below 1170. To meet the power required by the consumer, the battery group must give power more than the third loading situation. As it can be seen from the simulation results given in Fig. 10, the consumer is fed by hybrid power generation system with battery support. 414W of the power drawn by the consumer is provided from the wind power generation system, 495W of it from solar power generation system and 640W of it from the battery group. VII. CONCLUSIONS: To increase the use of renewable energy sources, first of all, the level of knowledge on the renewable energy sources at universities and other sections of society must be increased. Thanks to the installed wind-solar hybrid power generation system with battery support at Kakatiya University. The university students have acquired knowledge on the system elements and system installation. By introducing the proposed system to Warangal public, they have seen provided with information about electricity generation with the hybrid power generation system. When the curves obtained from simulation results of the hybrid power generation system modeling study are examined, it is seen that there is not a substantial difference in electrical and mechanical magnitudes in @IJAERD-2017, All rights Reserved 1192
parallel to the dynamic behavior of installed hybrid power generation system. By comparing the real system data and simulation study data, it has been determined that the accuracy analysis of the realized simulation study related to the hybrid power generation system is very good. Thanks to the installed hybrid power generation system, students will be able to make real time studies about renewable energy sources and on such subjects as electric generation, system control, productivity of generated energy, etc. VIII. FUTURE SCOPE In the future, as a further step of this study, a fuel cell (FC) system and a diesel generator will be added to the proposed hybrid wind-solar power generation system. A hybrid solar-wind-fuel cell and diesel power generation system would require effective use of advanced control techniques for high-performance and reliable operation. The better control techniques such as the artificial neural network, adaptive neuro-fuzzy inference system and Fuzzy-PID control can be used to further improve the performance of the hybrid solar-wind-fuel cell and diesel power generation system. REFERENCES [1] R. Chedid and S. Rahman, Unit sizing and control of hybrid wind-solar power systems.ieee Transactions on energy conversion, Vol. 12, No.1, March 1997, pp. 79-85. [2] Habib M.A,Said, S.A.M El Hadidy, M.A. I. Al-Zaharna, Optimization procedure of a hybrid photovoltaic wind energy system, 1999, Energy, Vol.24 pp 919-929 [3] Hans George Bayer, Christian Langer, A method for the identification of configurations of pv/wind hybrid systems for the reliable supply of small loads, Solar Energy vol 57 no.5 pp 381-3911, 1996. [4] Morgan, T.R.,Marshall R. H., B.J. Brinkworth,1997 ares a refined Simulation program for the sizing and Optimization of autonomous hybrid energy systems, Solar Energy Vol.59,No.6. [5] S.Diaf, D. Diaf, M. Belhamel, M. Haddadi, and A. Louche, A methodology for optimal sizing of autonomous hybrid PV/wind system, International Journal of Energy Policy, Vol. 35, pp. 5708-5718, 2007. [6] Rajveer Mittal, K.S.Sandu ve D.K.Jain, Battery Energy Storage System for Variable Speed Driven PMSG for Wind Energy Conversion System, International Journal of Innovation, Management and Technology, Vol. 1, No. 3, August 2010 ISSN: 2010-0248 [7] A. El Ali, N. Moubayed and R. Outbib, Comparison between solar and wind energy in Lebanon, 9th International Conference on Electrical Power Quality and utilization, 9-11 October 2007, Barcelona SpainF. [8] S. Barsali and M. Ceraolo, Dynamical Models of Lead-Acid Batteries: Implementation Issues, IEEE Transactions on Energy Conversion, Vol. 17, No. 1, Mars 2002D [9] N. Moubayed, J. Kouta, A. El-Ali, H. Dernayka and R. Outbib, Parameter identification of the lead-acid battery model, 33rd IEEE Photovoltaic Specialists Conference, 11-16 Mai 2008, San Diego, Californie USAF. [10] Valenciaga, F., Puleston, P.F., Battaiotto, P.E., Power Control of a Solar/Wind Generation System Without Wind Measurement: A Passivity/Sliding Mode Approach, IEEE Transactions on Energy Conversion, vol.18, no.4, pp. 501-507, 2003. [11] Borowy, B.S.; Salameh, Z.M., Optimum photovoltaic array size for a hybrid wind/pv system, IEEE Transactions on Energy Conversion, Volume 9, Issue 3, Sept. 1994 pp.482 488. [12] S.B. Bogdan, and Z.M. Salameh, Methodology for optimally sizing the combination of a battery bank and PV array in a wind/pv hybrid system, IEEE Trans. on Energy Conversion, Vol. 11, pp. 367-375, 1996. @IJAERD-2017, All rights Reserved 1193