Fuzzy Based Hybrid Solar-Wind Energy Harvesting Using Mppt Control Technique

Transcription

1 Indian Journal of Science and Technology, Vol 9 S(1), DOI: /ijst/2016/v9iS(1)/ December 2016 ISSN (Print) : ISSN (Online) : Fuzzy Based Hybrid Solar-Wind Energy Harvesting Using Mppt Control Technique T. S. Balaji * and Satyam Electronics and Communication Engineering, SRM University, Vadapalani, Chennai , Tamil Nadu, India; balaji1381@gmail.com, satyamb50@gmail.com Abstract Objective: Modeling of a hybrid system is a powerful device which utilizes solar energy and energy source from the wind which is given to the DC bus that will in turn produce the power supply without any disturbances. Methods/Analysis: In this paper, depending upon the requirement the load is driven either by wind energy or solar energy. The alternative sources of energy are connected to a DC-DC converter by means of a current source. Findings: To reduce the unwanted components or hardwares this model is implemented with low cost power converter. A fuzzy logic based wind/solar combined model is designed for 30 KW. The load voltage obtained is 300 V and the load current obtained is 0.1 KA. In this solar/wind combined system, the power which is generated by wind runs at an average speed. The maximum power can be obtained with the introduction of fuzzy logic concept along with photovoltaic arrays which is used under incremental conduction algorithm. Novelty/Improvements: The maximum power can be derived from more than two renewable resources by using this hybrid system. Keywords: Fuzzy Logic, Maximum Power Point Tracking, Solar Panel, Uninterrupted Power Supply, Wind Turbine 1. Introduction Due to fluctuation of price of natural gases, the alternative natural energy sources place an important role. If many number of sources are ready to run the single load, then the load must be uninterrupted by those sources and this will be considered as a major job 1. The two important energy sources are solar and wind energy which is discussed in this paper. Because of its unique external feature like production capacity these energy sources are plays an important role. These energy sources behave differently and its performances are different in an entire day or entire year that is with respect to sun light or seasons. A separate system is required to manage the energy in order to select a proper source of energy to provide the power without any disturbances to the load. Because, it is not desired amount of power which will be provided by the source, the capacity of source can be change at any time 2. The output power of the solar panel can be measured with the help of current and voltage sensors. The panel always monitors that the requirement of power to the load. The multiple energy resources can be switched one from another with the help of relay circuitry 3. When comparing with the other controllers the PIC microcontroller identified as best, because of its unique advantages like operating speed is fast, RISC architecture and the whole system can be designed compact and cost effective manner with the help of internal ADC 4. The major disturbances or interferences occur due to human being and the losses due to electricity which can be reduced by large amount when the entire process takes place automatically. 2. Present System To produce the power any one of the renewable resources is utilized in the present system. The sun doesn t shine 24 hours a day. The production of electricity is mainly depends on sun when the PV panels are used. The energy which will be produced by sun take part an important role. At a given point of time and place the amount of light energy produced from solar sources are essential. Because of solar energy varies at irregular * Author for correspondence

2 Fuzzy Based Hybrid Solar-Wind Energy Harvesting Using Mppt Control Technique intervals 5. The output power which will be obtained from solar energy is not same throughout the day or seasons. The power may or may not produce depend upon the weather conditions. The power which will be generated by the wind turbine is not a predictable energy resource. Its electricity generated property can be varied with the following constraints: Wind speed, air density and wind turbine characteristics. The production of the electricity from the wind turbine completely depends on the turbine speed. When the turbine speed is increases very high then in order to overcome from damage the wind turbine is getting to be shutdown. The output is completely depending upon the single turbine. It means that the output power is mainly depends upon the rotation speed of the wind turbine. The discussed alternative resources like solar and wind energy are not consistent because they produce the output power irregularly. These sources will never be able to contribute the significant power supply or to drive the load Proposed System Any one of the active resources like solar or wind energy can be utilized to generate the power in this proposed system. When one particular energy resource is too low, then it automatically switches its resource which will have abundant energy. The electricity which is generated from the solar energy can be balanced by the production of electricity from the wind when it is oscillating. The weather condition cannot predict some locations. It could be winder, cloudy or stormy weather. Some time wind energy is more when compared with solar energy. The load is designed in such way that it utilizes the available resources efficiently and it accepts the energy from much number of sources PIC Microcontroller Peripheral Interface Controller is represented with the abbreviation of PIC. A various embedded systems can be controlled by a processor based system which is termed as microcontroller. A processor, memory and peripherals are the major blocks of a typical microcontroller. EEPROM (Electrically Erasable Programmable Read-Only Memory) where can be re-programmed easily, low cost and development tools are the important features of this PIC microcontroller. It supports the latest development tools which are required by the modern engineers. The specification of the PIC microcontroller is shown in Table 1. The microcontroller is programmed in such a way that it will be continuously comparing the input received from both the sources i.e. the wind turbine and the solar panel with the load requirement so that the specified output is reached. In other words microcontroller will be reading the load requirement and based on that it will be switching the sources using the relay circuit to supply the power and charge the battery such that the continuous load requirements are met. Table 1. Specification of PIC microcontroller FLASH RAM EEPROM TIMERS OPERATING PACKAGING MEMORY (BYTES) (BYTES) RANGE (V) 8K X X X TO /40/44 Table 2. Comparison of microcontrollers PART NUMBER RAM ROM I/O PINS TIM ERS INTER RUPTS VCC PACKA GING AT89C51 4K V 40 AT89LV51 4K V 40 AT89C1051 1K V 20 AT89C2051 2K V 20 AT89C52 8K V 40 AT89LV52 8K V 40 AT89S2 8K V 40 PIC 8K V 28/40/44 2 Vol 9 S(1) December Indian Journal of Science and Technology

3 T. S. Balaji and Satyam 3.2 MPPT A MPPT is nothing but a DC-DC converter which acts as an interface between the solar panels and battery bank that has to be charged. The main purpose of the MPPT is to obtain the lower DC voltage which is required to charge the batteries from the solar panels and the wind generators whose DC output is very large 10. This paper discusses about the concept of panel tracking where in the panels which are mounted always follows the sun. The panel tracking circuit is designed in such a way that it receives maximum sun light at all the times 8. Due to the season variations, during the winter season it requires more power from the solar panels. The MPPT is a digital electronic tracker in which the output voltage from the solar panels is compared with the voltage of the battery bank. Based on the necessity of the voltage of the battery bank the solar panel provides the voltage. MPPT s are highly efficient. The gain of the MPPT is dependent upon humidity, temperatures, battery charge and other factors 9. The following conditions are important, so that MPPT s are required to take certain actions. Solar panels works better in all the seasonal conditions whether it is summer or winter. But during the winter season the MPPT s play an important role because it always track the sun light, whenever the sun light is more it immediately take up for charging. The extra power is required mostly during the winter season. It track the status of the battery if it shows the lower state then immediately take up for charging as well as at the same time it must do action that presently processing. 3.3 Fuzzy Logic Fuzzy logic is defined to go for several options instead of using only two options it means that the binary options 0 s and 1 s. From this approach, we can obtain several degrees of truth. Fuzzy logic means that it examines the truthiness of the certain experiment. It rarely includes the binary value 0 and 1 and it is used only for the extreme false or extreme truth. When a certain experiment is processing it examines the truthiness of the experiment by doing the aggregate of the earlier results and suppose it produces a partial truth then again it will go for further higher truths. With a result of that it concludes the truth and it resembles near to the human brain. In a simple way of explaining, fuzzy logic is a special case or special way of expressing the Boolean logic. As discussed above, the fuzzy logic is not only describes about binary 0 or 1. It may take several steps between binary 0 and 1. Binary 0 represents completely false and binary 1 represents completely true. The Fuzzy logic approach may take various steps between 0 and 1 which will be described by the user or designer. The entire control can be made step by step in all the degrees or directions. Fuzzy logic is the key algorithm used in this paper. The values received from the sources like wind and solar are continuously varying since the atmospheric conditions will not be same all through the day or a week. Thus the values obtained from the sourced are computed using the fuzzy logic using which the sources are switched on and off in the circuit for charging the battery using the relay circuit. For instance if the sun is at the peak then whole process of charging the battery will be carried out using the solar panel alone and wind turbine will be at off stage by the fuzzy logic. Similarly if the wind is more thereby the fuzzy logic solar panel will not be involved in the process charging of the battery. Figure 1. Block diagram. 3.4 Solar Panel The major source of energy for solar panel is a sun ray or sun light. It generates the electricity by absorbing the sun light. A section of solar cells packaged together is normally called as photovoltaic module. In many of the major Vol 9 S(1) December Indian Journal of Science and Technology 3

4 Fuzzy Based Hybrid Solar-Wind Energy Harvesting Using Mppt Control Technique applications the electricity resource is available from the solar array of photovoltaic system. The generated DC power output is different for different photovoltaic module. From the DC power output we can easily describe that, whether the photovoltaic module is single or multiple 10. Photovoltaic system is not only describing about the solar panel modules, it is a study of interconnection of battery and a solar tracker which will be made up of solar panel modules. smallest turbines are most widely used. The turbines are also made up of horizontal or vertical axes depend upon the requirement of particular application. The wind turbine is automatically switched on and off using the relay circuit. The wind turbine is switched on when the solar power goes down or when the load is more such that both the sources could charge the battery and obtain the desired load. Thereby switching off when load is decreased or the sunlight is plenty. Since, this paper discusses about the smallest turbine, the largest turbines also plays an important role in electrical grid. The electrical grid is used to provide the power to the domestic appliances and unused power to the other customers who need of power which will be generated by slightly larger turbines. It is treated as an important energy resource in many of the countries where the power requirement is more. Figure 2. Solar panel. Table 3. Position of solar panel with respect to LDR s LDR 1 LDR2 LDR3 POSITION LEFT CENTER RIGHT As from the Table 3 it is clear that based on the input of the three LDR s the solar panel is made to move or take shift in its angle. When the LDR 1 is at high and the other two are low then the position of the solar will be at the left side. This side shift will be generally seen during the morning hours. In second case when the LDR 2 is at high and the other two are low then the position of the solar panel will be at the centre thereby maintain the angle of a straight line. This kind of position is seen during the noon hour when the sun will be on our forehead. In the third case when the LDR 3 is at high and the other two are at low solar panel will be shifting towards the right. This kind of position of the solar will be during the time when the sun is about to set down. Comparing all the three the power obtained at the position 2 i.e. at the centre position will be high. 3.5 Wind Turbine The wind turbines are manufactured in different forms like largest and smallest turbine wings. The battery charge applications and certain other small applications the Figure 3. Wind turbine. 4. Results and Discussion In order to verify the modeling of wind turbine, a ramp input is given to the rotor speed at a particular wind speed. The variation of power developed with the variation of rotor speed at different wind speed. It shows that for different wind speed maximum power is obtained at different rotor speed. The maximum power mainly depends upon the rotor speed. When the turbine is connected to the system the input to the wind turbine is given in the form of step signal having initial value 20, final value 21 at a step time of 5 second in order to represent change in wind speed from 20 m/s to 21 m/s. The rotor speed is given initially a value of 100 rad/sec till PMSG develop a speed more than that. After the developed speed of PMSG become more than 100 rad/sec that value is given as the input rotor speed of wind turbine. 4 Vol 9 S(1) December Indian Journal of Science and Technology

5 T. S. Balaji and Satyam Figure 4. Variation of power due to change in rotor speed at different wind speed. In order to verify the modeling of solar array, a ramp input is given as the current at a particular temperature and solar irradiation. The VI characteristic and PV characteristics at different temperature and solar irradiation is shown in the Figure 5 and Figure 6. From Figure 5 and Figure 6 it is clear that as the solar irradiation increases the maximum power and voltage corresponding to maximum power increases. Figure 5. Variation of power due to change in voltage at different value of solar irradiation. Figure 6. Variation of current due to change in voltage at different value of solar irradiation. 5. Conclusion The power is obtained from the renewable resources which will be connected together in this system. The energy is utilized efficiently from any one of the interconnected resources. The electricity which is generated from the solar energy can be balanced by the production of electricity from the wind when it is oscillating. The power can be obtained to the load either by solar or wind or combined. The load can be driven either by solar or wind by means of supply the power. An efficient relay circuitry is utilizes solar energy and energy source from the wind which is given to the DC bus, that will in turn produce the power supply without any disturbances. Future work will be testing the system with real time data and comparing it with real-world scenario and the fuzzy logic can be applied to more than two renewable energy sources. 6. References 1. Yang H, Wei Z, Chengzh L. Optimal design and techno-economic analysis of a hybrid solar-wind power generation system. Applied Energy Feb; 86: Dihrab S, Sopian K. Electricity generation of hybrid PV/wind systems in Iraq. Renewable Energy Jun; 35: Reichling JP, Kulacki FA. Utility scale hybrid wind-solar thermal electrical generation: A case study for Minnesota. Energy Apr; 33: Ekren O, Ekren BY, Ozerdem B. Break-even analysis and size optimization of a PV/wind hybrid energy conversion system with battery storage A case study. Applied Energy Jul-Aug; 86: Kim SK, Jeon JH, Cho CH, Kim ES, Ahn JB. Modelling and simulation of a grid-connected PV generation system for electromagnetic transient analysis. Solar Energy May; 83: Tsai HL. Insolation-oriented model of photovoltaic module using MATLAB/Simulink. Solar Energy Jul; 84: Khan MJ, Iqbal MT. Dynamic modelling and simulation of a small wind fuel cell hybrid energy system. Renewable Energy Mar; 30: Chayawatto N, Kirtikara K, Monyakul V, Jivacate C, Chenvidhya D. DC AC switching converter modellings of a PV grid-connected system under islanding phenomena. Renewable Energy Dec; 34: De Battista H, Mantz RJ, Garelli F. Power conditioning for a wind-hydrogen energy system. Journal of Power Sources Apr; 155: Rezvani A, Izadbakhsh M, Gandomkar M, Vafaei S. Investigation of ANN-GA and modified perturb and observe MPPT techniques for photovoltaic system in the grid connected mode. Indian Journal of Science and Technology Jan; 8(1): Vol 9 S(1) December Indian Journal of Science and Technology 5