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Similar a Getnet thesis ppt 2013 Final (2).ppt(20)


Getnet thesis ppt 2013 Final (2).ppt

  2.  Introduction  Statement of The Problem  Objectives  Significance of The Study  Literature Review  Methodology  Modelling of The System  Equivalent Circuit of PV Cell  Designing of MPPT Using Fuzzy Logic Control  Results and Discussion  Conclusion and recommendation Outline
  3. INTRODUCTION Solar PV power system is a competitive source of electricity growing at a rapid rate due to the reason abundantly available, clean, noise and pollution free Solar photovoltaic system is widely in use among others alternative sources of electricity The basic factors that contribute to the reduction of output power from PV arrays are :  Radiation  temperature  partial shading and etc
  4.  Basic challenges for efficient tracking and utilization of PV power are :  Low conversion of efficiency,  Dependent on atmospheric/climatic conditions  Partial Shading  Non-linear characteristic  High initial investment requirement and  It needs techniques / controller for efficient tracking and utilization of the available power. Statements of the Problem
  5. Cont.  Some of the drawbacks of widely used classical techniques are :  failure to track the right direction of perturbation,  Problems on steady-state oscillation and  failure to track GMPP under partial shade condition  Therefore we need to effectively tracking at GMPP, minimize power loss and also improve the above drawbacks
  6. General Objective: The general objective of this thesis is:  To design and simulate FLC for MPPT of PV power system under partial shade condition. Specific Objectives; The specific objectives of this thesis are :  To identify forms of utilization, basic tasks and components required for efficient tracking of PV power system  To develop fuzzy-logic based MPPT algorithm that is able to respond quickly during partial shade condition Objectives
  7. Cont.  To be able operate the PV system at/near global MPP under partial shade  To perform the Simulation of the overall PV system in MATLAB/Simulink.  To compare the fuzzy-logic based algorithm to the classical methods.
  8. This thesis will provide the following significances  Better utilization of solar power system  Increases reliability and availability of electrical energy  Increase life span of the solar system components  Decreases energy consumptions  Increases the ability to maintaining MPPT during partial shading condition  Improving the quality of the controller  Evaluate the performances of MPPT based on the simulation results and etc Significance of the study
  9.  Some of basic studies done in related to MPPT system are given below on the next table: Year and Name of the authors Title Benefits Draw backs In 2017 Dr. R. Sankar et al A PV system using fuzzy logic and a dual- MPPT controller opposite direction leading to oscillations and also improve the efficiency during Uniform shading It is not considered the partial shading conditions of PV of solar Literature Review
  10. cont… Year and Name of the authors Title Benefits Draw backs In 2017 Palliva Verma et al, Comparison of intelligent and classical MPPT (P&O) algorithms for PV system under Partial shading During STC good output power and Partial shading is considered. Power output value is below the expectation during Partial Shading. Tests only a single string .
  11. cont… Year and Name of the authors Title Benefits Draw backs In 2017 S. Malathy and R. Ramaprabh a MPPT Algorithm of SPVA (solar PV array) under Inhomogeneous Irradiation Conditions: a Modified Fibonacci Search Based Approach Easy to implemen t in experimen tally Its more of classical methods that is it takes high settling time and tests only radiation change but not temperature factors In 2013 Lixia Sun et al proposed that MPPT with fuzzy control then Compared with the conventional achieves better effect in terms of speed Its not effective for partial shading conditions.
  12. Year and Name of the authors Title Benefits Draw backs In 2017 Mahima Sunar and, "Study of Intelligent MPPT Controllers for a Grid Connected PV System For grid system its good output had performed Not implement on the off grid system but the current problem is for the off-grid system in the rural area In 2014, P. Srinivasa Rao Comparison of different interconnection schemes based on shading conditions and shading levels Very Easy due to only consider the interconnection schemes (there is not have extra algorithm / controller) . Control system is not accurate. Or it’s classical control system and only focused on interconnection schemes Cont…
  13. Methodology 1 • Conduct literature review: I had been reviewed some of related to the problem intended to address and to refine more the approaches to solve the problems and result presentations. 2 • Modeling Photovoltaic System : I had been modeled the MPPT controller on the considerations of partial shading, efficiency, atmospheric conditions , accuracy and etc 3 • Develop the Algorithm: I had been developed the algorithm by considering of the error, steady-state oscillation and tracking at the global MPP under partial shade condition
  14. Cont. 4 • Design of Photovoltaic System: To verify performance of the proposed model by comparison with the classical one. 5 • Simulation : the proposed controller algorithm and design will be done using MATLAB/Simulink modeling and simulation 6 • Result and Discussion : According to the design and simulation the result will be briefly explained
  15. Modeling Photovoltaic System PV Cell generates power by converting sunlight to electricity.  The electric current generated is proportional to solar radiation. To extract the maximum power from PVs, their mathematical model , which can predict their nominal voltage and nominal current, should be investigated Modelling of The System
  16. Equivalent circuit of PV cell The equivalent circuit of a PV cell includes diode, shunt resistance, series resistance representing an internal resistance to current flow and current source is illustrated in Figure below Using an equivalent circuit diagram, i.e. a current source in parallel with a diode. Further addition of components like series, parallel resistor and parallel diodes are to improve accuracy of simulation
  17. On the above equivalent circuit diagram representation a single diode five parameters (Rsh) model is widely used being a compromise in simplicity and accuracy Cont... Ideal PV cell is modeled as a solar irradiance dependent current source, Iph is parallel with a diode. The photocurrent depends on solar radiations and affected by cell’s operating temperature (Tc) which given as in the eq 3-1 below:
  18.  The basic equation from the theory of semiconductors that mathematically describes the I–V characteristic of the PV cell are given in Eq 3-2 to 3-7 : Cont...
  19. Cont...
  20. cont…
  21. Fig: Modeling diagram of the characteristics equations Cont...
  22. Designing of MPPT using fuzzy logic control FLC based MPPT technique can be formulated with different options of input/output parameters of the PV system. The input parameters can be error (E) and change in error ΔE or change in PV power (ΔP) and change in PV voltage (ΔV) or change in PV current ( ΔI) The output of change in duty cycle (ΔD) reference voltage (ΔVref) or change in reference current (ΔIref)
  23. The second possible option with inputs of ΔVpv and ΔPpv is supposed to solve the drawbacks of FLC based MPPT technique using error and change in error inputs, can be described using expressions in equations below: Block diagram of FLC MPPT algorithm Cont...
  24. Figure : Flow chart algorithims of FLC MPPT with the I/O of the above two cases Cont...
  25.  FLC based MPPT with inputs of PV voltage and power variation and output of a change in reference voltage mapped each I/O to 7 different linguistic variables, a total 49 rules and input/output membership functions are given below on the table: Cont... ↓∆V/∆P→ NB NM NS ZR PS PM PB NB NB NM NS ZR PS PM PB NM PB PB PM ZR NM NB NB NS PB PM PS ZR NS NM NB ZR PM PS PS ZR NS NS NM PS NB NM NS ZR PS PM PB PM NM NS NS ZR PS PS PM PB NB NM NS ZR PS PM PB If the input ∆V is NB and ∆P is NB then the output is NB If the input ∆V is NB and ∆P is NM then the output NM
  26. Block diagrams of FLC based MPPT
  27. if dI/dV > -I /V , thus V <V max ; if dI/dV < -I /V , thus V >V max if dI /dV = - I/V , thus V =V max ; Algorithms of Incremental conductance
  28. Fig: Schematic diagrams of a single PV string
  29. Fig: Schematic diagrams of a multiple PV string
  30. On this section the results of the proposed controller is compared with the classical InCond, basically I use five basic factors/conditions PV system, these are:  Variable Temperature Variable Irradiations Both temperature and Irradiations are variable Constant Temperature but variable Irradiations Constant Irradiations but variable temperature Results and Discussions
  31. 0 50 100 150 200 250 0 200 400 600 800 Voltage (V) Power(W) Case1 Higher Range Case 2 Medium Range Case 3 Lower Range Fig: Outputs of Constant radiation with variable temperature value 0 50 100 150 200 250 0 100 200 300 400 500 600 700 800 900 VOLTAGE (V) POWER(W) constant Rad.but Varaible T during STC both T & Rad are varyed Constan Tbut Variable Rad Fig : Comparative output value of different cases Cont...
  32. 0 50 100 150 200 250 300 -2 0 2 4 6 8 10 voltage (v) current (A) SP1 SP2 SP3 SP4 Fig : I-V Characteristics curve using FLC Parameters of different Shading patterns (SP) for simulation purpose
  33. 0 20 40 60 80 100 120 0 200 400 600 800 1000 Voltage (V) Power(w) Using InC US SP1 SP2 SP3 SP4 0 50 100 150 200 250 0 100 200 300 400 500 600 700 800 900 Voltage (V) Power (w) SP4 SP3 SP2 SP1 US SP4 SP3 SP2 SP1 Using FLC Uniform Shading Figure : MPPT with different shading patterns of P-V Trajectories Cont...
  34. Table : MPPT value using FLC and InCond algorithm Table: Efficiency of different shading pattern of the proposed controller and InCond: Shading Patterns FLC InCond SP1 99.9976% 95.4433% SP2 99.9889% 95.4433% SP3 99.9879% 94.7857% SP4 99.9998% 97.7773%
  35. Table: Comparison of MPPT deviation of FLC and the classical one The deviation records revealed that capability of FLC to track the GMPP accurately than classical methods Cont...
  36. steady state performance Step change from SP3- to –SP4 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0 100 200 300 400 500 600 700 Time(sec) power(W) Output power using FLC Expected power value 0.025 0.03 0.035 0.04 627.5 628 628.5 629 629.5 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.4 0 100 200 300 400 500 600 700 Time(sec) power(W) SP3 SP4 During step change from shade pattern4 to shade pattern3 (SP4 to SP3) at t=0.25second there is search range to locate GMPP Using FLC technique shows very small search range , small amplitude of oscillation and low steady-state error than the InCond Cont...
  37. CONCLUSIONS During partial shading conditions, the PV characteristics curve comprises of multiple local and global peaks. Accordingly performance evaluations for a given shade patterns of a PV system have been done and tracks the GMPP of PV systems under partial shade conditions. According to the above simulations results I concluded that the proposed controller has the following benefits than the classical one : faster response, accurate global peak power tracking capability, low steady sate oscillation, higher performance and higher tracking efficiency as compared to the InCond algorithm techniques
  38. Recommendations Solar photovoltaic system is widely in use among others alternative sources of electricity and currently it’s a new technology and a highly demand in the world, there fore I want to recommend that : Further research will be done in the combination of intelligent control algorithms and classical control methods On the future work, I will recommend that better to do the hardware implementation using microcontroller in experimentally to confirm the performance of proposed algorithm
  39. ??? Thank you !!!