1. Presented By Malik Sameeullah M.Tech (RES) NATIONAL INSTITUTE OF TECHNOLOGY, KURUKSHETRA 1

2. Contents Solar PV Sector Type of Solar PV system Need of Charge Controller and MPPT Solar PV Cell: Basic model Type of Battery: features and characteristics Basic Charge controller model Buck Boost Converter MPPT model MPPT Based Optimum Controller Design Conclusion Research Work and Future Work References 2

3. Solar Power Sector India lies in a sunny tropical belt (High insolation) Total approximate potential annually over 5000 trillion kWh Over 70% of India’s households experience significant power cuts every year National Solar Mission and other Generation Based Incentives (GBI) are available through Ministry of New and Renewable Energy (MNRE) JNNSM have a mission to install 20 GW solar PV plant by 2022 Cost of PV module, land scarcity and technological barrier is a main restriction. Current cost of production is ` 12/KWh and expected cost is ` 6/KWh by 2020 3 Jawahar Lal Nehru National Solar Mission Target 2010-2013 On grid PV power of 1000-2000 MW Off grid PV application 200 MW Solar collector 7 million sq. meter 2013-2017 On grid PV power of 4000-10000 MW Off grid PV application 1000 MW Solar collector 15 million sq. meter 2017-2022 On grid PV power of 22000 MW Off grid PV application 2000 MW Solar collector 20 million sq. meter

4. Type of Solar PV System Solar PV System Grid Connected PV Large scale production (Without Battery) With Battery ( Smart Grid concept ) Off Grid PV System With Battery (e.g. for houses and industries) Without Battery (PV water Pump) Hybrid PV System Wind-PV hybrid system PV-Diesel hybrid System PV based Utilities Solar Lamp, Solar mobile charger etc. 4

5. Need of Charge Controller and MPPT Battery is a costly device and must be managed properly. It is found if proper care is taken then life of battery increase significantly A charge controller limits the rate at which electric current is added to or drawn from electric batteries Charge Controller take care of battery under voltage and over voltage condition MPPT (Maximum Power Point Tracker) is a electronic device which maximize PV module output under varying operating condition 5

6. Solar PV Cell: Basic Model Illumination Dark condition I V 6

7. Solar PV Diode Model Equivalent circuit of PV cell I-V curve of PV cell P-V curve of PV cell 7

8. Battery The cell is the basic electrochemical unit in a battery, consisting of a set of positive and negative plates divided by separators, immersed in an electrolyte solution and enclosed in a case. Nominal cell voltage is 2.1 V for lead acid battery Primary function of battery in PV system: 1. Energy storage and autonomy 2. Voltage and current stabilization 3. Supply surge current 8

9. Secondary battery types and characteristics Battery TypeCostDeep cycle Performance Maintenance Flooded Lead Acid Lead Antimony LowGoodhigh Lead-Calcium open vent LowPoorMedium Lead-Calcium sealed vent LowPoorLow Lead Antimony/Calcium hybrid MediumGoodMedium Captive Electrolyte Lead Acid Gelled MediumFairLow Absorbed glass Mat MediumFairLow Nickel-Cadmium Sintered Plate HighGoodNone Pocket Plate highgoodMedium 9

10. Battery Parameters Battery Capacity (Ah): It is the maximum charge storage capacity of a battery. Battery Voltage (V): It is the terminal voltage of battery under no load condition Depth of Discharge (DoD): This is a measure of how much energy has been withdraw from a battery. Battery Life cycle: It is defined as number of complete charge-discharge cycle that battery can perform before it nominal capacity fall below 80% of initial value Graph between Depth of Discharge and Life cycle of batteries(data is approx.) 10

11. Factor Affecting Battery Performance Operating voltage range Magnitude of battery discharge current Battery temperature during discharge Choice of battery for particular application Ideal charging characteristics for a lead-acid battery 11

12. DC-DC Converter Used for converting DC voltage from one level to another It is used to convert unregulated DC into a controlled DC output Suitable for PV system where due to change in atmospheric condition DC output change continuously It is also a basic component of MPPT system 12

13. Topologies of DC-DC Converter Isolated type converter Flyback Half Bridge Full Bridge Non-Isolated type converter Buck-Boost SEPIC Cuk Grid tied system used this topologies, as isolation is required for safety reason Most of the DC drive used this converter. No need of transformer. 13

14. Basic Converter It consist of switch which operate continuously to maintain output voltage Fundamental switching converter circuit 14

15. BUCK Converter Used for step down of DC voltage BOOST Converter Used for step up of DC voltage 15

16. BUCK-BOOST Converter The basic principle of the buck–boost operation 1.While in the On-state, the input voltage source is directly connected to the inductor (L). This results in accumulating energy in L. In this stage, the capacitor supplies energy to the output load. 2.While in the Off-state, the inductor is connected to the output load and capacitor, so energy is transferred from L to C and R. Buck Boost Converter 16

17. Type of Charge Controller Shunt Type Charge Controller Series Type Charge Controller DC-DC Converter Type Charge Controller MPPT Charge Controller Shunt Converter Series Converter No additional losses due to switch and better regulation of battery charging DC-DC converter PV array LOADLOAD 17

18. Maximum Power Point Tracking It consist of electronic circuit allow to collect maximum power from PV module under different condition PV array R 18 a b c b’ c’

19. Hill Climbing Method Hill climbing method fail under rapid environment change condition 19

20. Algorithm of Hill Climbing Method Start Set duty Yes No 20

21. Standalone PV System For standalone system to category of converter used, 1. Renewable side converter (RSC) and 2. Storage side converter Inputs are actual PV voltage, PV current, battery voltage and battery current Measurement of battery current provide additional protection again overcurrent condition Circuit diagram of charge controller 21

22. Optimal Charge Controller Logic Controller of DC-DC converter 22

23. Study of Output Response of Controller Conventional controller output Hill Climbing MPPT Method track for maximum power and for battery voltage higher than maximum limit than need to open switch Proposed scheme It always track for maximum power condition. when battery voltage or current is above the set limit than it try to push converter toward low power extraction region and provide better charging control 23

24. Conclusion In solar PV based battery charging, MPPT algorithms are used When the state of charge (SoC) of battery is high and system is on no-load, excess power flows into the battery This results in low operational life of the battery Slight variation in design of MPPT improve the charging condition of battery 24

25. Research Area and Future Work There is number of MPPT control algorithm. Fuzzy and Neural network based MPPT algorithm are more accurate. No of improved DC-DC converter topologies are in picture like CUK converter, Isolated converter etc. By choosing the optimal combination of DC-DC converter and MPPT algorithm better regulation of battery is possible 25

26. References 1. Sandeep Anand, Rajesh Singh Farswan, Bhukya Mangu, B.G. Fernades, “Optimal charging of Battery Using Solar PV in Standalone DC System,” Industrial Electronics Magazine, vol.7, no-3,pp.6 – 20, Sep 2013 2. Trishan Esram, and Patrick L. Chapman, “Comparison of Photovoltaic Array Maximum Power Point Tracking Techniques,” IEEE Trans. on Energy Conversion, vol. 22, no. 2, June 2007 3. Tom Markvark, Luis Castaner,” Solar Cells: Material, Manufactures and operation,” Elsevier, ISBN-1856174573 4. Chetan Singh Solanki, “Solar Photovoltaic: Fundamentals, Technology and Applications,” Eastern Economy Edition, ISBN-9788120343863 5. Simon S. Ang, “Power Switching Converters,” Marcel Dekker Inc., ISBN- 0824796306 6. Paras Karki, Brijesh Adhikary, “ MATLAB/Simulink based Modeling and Simulation of Gird-connected Solar Photovoltaic System in Distribution Power Network,”Fifth International Conference on Power and Energy Systems, Kathmandu, Nepal, pp.28 - 30 October, 2013 7. James P. Dunlop, P. E. Florida, “Batteries and Charge Control in Stand- Alone Photovoltaic Systems Fundamentals and Application,” Solar Energy Center1-679, Clearlake RoadCocoa, FL 32922-5703 26

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