FAULT ANALYSIS ON MAXIMUM POINT POWER TRACKING BASED GRID CONNECTED PHOTOVOLTAIC SYSTEM

1. FAULT ANALYSIS ON MAXIMUM POINT POWER TRACKING BASED GRID CONNECTED PHOTOVOLTAIC SYSTEM Presented By:- Mukesh Kumar Pandit(090101EER040) Jyotiranjan Behera (0901213206) Jagannath Mahapatra (0901213170) Jyoti Ranjan Sahu (090101EER019) Shiv Prasad Sahoo (090101EER007) Guided By:- Mr. Sibasish Panda (Assistant Professor)

2. CONTENTS • Introduction • components of grid connected photovoltaic power system • Schematic Diagram of grid connected PV system • control of three phase grid connected PV system • Simulation and Result • Conclusion • References

3. INTRODUCTION • As the world electricity consumption rapidly increases with population growth, new power generation capacities are required to cover that demand. So, there is need for power generation using renewable sources. Hence Photovoltaic System is implemented to tie with the power grid. • In order to extract maximum power output from PV system efficiently, MPPT technique is being used. • A DC/DC converter used which tries to match the load impedance to the ratio between voltage and current of the array at the maximum power point (MPP). • The converter used is a Voltage source inverter (VSI) which is controlled using synchronous d-q reference frame to inject a controlled current into the grid and Phase lock loop (PLL) is used in controller to lock grid frequency and phase . • Finally MPPT based Grid connected PV system was simulated using SIMULINK and a fault study was conducted to examine the behaviour of the system when the PV array was connected.

4. COMPONENTS OF GRID CONNECTED PV SYSTEM Several components are needed to construct a grid connected PV system to perform the power generation and conversion functions. • Photovoltaic system • DC-DC converter and Three-phase inverter • LC filter • Transformer • Utility Grid Figure 1: Components of a Grid Connected PV System

5. PHOTOVOLTAIC SYSTEM Modeling of PV cell Figure-2: Equivalent circuit diagram of PV cell Figure-2 shows the equivalent circuit of the PVcell, formed by a current source Iphin anti-parallel with diode driven by a current Id.

6. From Figure -2 applying KCL Finally, from the equivalent circuit of PV cell Ipv and Vpv are

7. EFFECT OF IRRADIANCE • Figure 3: I-V characteristics of PV module under different irradiation level

8. Figure 4: P-V Characteristics of PV module under different irradiation level

9. EFFECT OF TEMPERATURE Figure 5: I-V characteristics of PV module under different temperature level

10. Figure 6: P-V characteristics of PV module under different temperature level

11. DC-DC BOOST CONVERTER The boost DC converter is used to step up the input voltage by storing energy in an inductor for a certain time period, and then uses this energy to boost the input voltage to a higher value. Figure 7: Circuit diagram of Boost Converter The relationship between the input and output voltages is given by

12. THREE-PHASE INVERTER The three phase inverter is used to obtain a three-phase voltage output from DC source. Three-phase voltage source inverter is a combination of three single-phase bridge circuits. Figure 8: Three-phase inverter In grid connected PV system, the current output of the voltage source inverter will be injected to the grid. The output of the inverter should be in phase and have an identical frequency to the voltage of the grid.

13. SCHEMATIC DIAGRAM OF GRID CONNECTED PV SYSTEM Figure 9: Schematic diagram of grid connected PV system

14. CONTROL OF THREE PHASE GRID CONNECTED PV SYSTEM • The DC/DC boost converter is controlled using a maximum power point tracking technique . • For inverter control system dq transformation and SVPWM technique are being used. • Grid synchronizations plays important role for grid connected systems. PLL technique is employed to synchronise the output frequency and phase of grid voltage with inverter voltage using different transformation.

15. MAXIMUM POWER POINT TRACKING As the amount of power produced by the PV module varies greatly depending on its operating conditions (temperature and irradiation). Hence, there is need to constantly track the power curve and keeps the solar panel operating voltage at the point where the most power extracted. This process is known as maximum power point tracking. Figure 10: I-V & P-V curve at maximum power point

16. Description of Perturb-and-Observe Algorithm Figure-11: Flow Chart of perturb and observe algorithm

17. abc/dq TRANSFORMATION The dqtransformation is used to transform three phase system quantities like voltages and currents from the synchronous reference frame (abc) to a synchronously rotating reference frame with three constant components when the system is balanced.The relationship that govern the transformation from the abcto dqframe is Where f can be either a set of three voltage or current to be transformed T is the transformation matrix The direct and quadrature components of the inverter output current can be used to control the active and reactive output powers from the PV array system

18. SVPWM TECHNIQUE The space vector PWM (SVM) method is an advanced, computation-intensive PWM method . space vector PWM can be implemented by the following steps Step 1. Determine Vd, Vq, Vref, and angle (α) Step 2. Determine time duration T1, T2, T0 Step 3. Determine the switching time of each transistor (S1 to S6) where f = fundamental frequency.

19. PHASE LOCKED LOOP TECHNIQUE The role of the phase locked loop is to provide the rotation frequency, direct and quadrature voltage components at the point of common coupling (PCC) by resolving the grid voltage abccomponents. Figure 12: Schematic diagram of the phase locked loop (PLL) where is rotation frequency in rad/s is rotation angle in radians

20. PLL SIMULINK MODEL Figure 13 :Simulink model of PLL

21. VSI CONTROLLER SIMULINK MODEL Figure 14 :Simulink model of VSI controller

22. SIMULATION MODEL OF GRID CONNECTED PV SYSTEM Figure 15: Simulink Model of Grid Connected PV System

23. Voltage, Current and Power Output of PV array without MPPT

24. Voltage, Current and Power Output of Boost Converter with MPPT

25. FAULT ANALYSIS • Without Fault LG Fault LL Fault LLG Fault LLL Fault LLLG Fault

26. WITHOUT FAULT

27. GRID VOLTAGE & CURRENT WAVEFORMS

28. P-Q WAVEFORMS

29. INVERTER VOLTAGE & CURRENT WAVEFORMS

30. THD FOR GRID VOLTAGE IN PHASE A

31. THD FOR GRID CURRENT IN PHASE A

32. THD FOR INVERTER VOLTAGE IN PHASE A

33. THD FOR INVERTER CURRENT IN PHASE A

34. LG FAULT

35. Grid Voltage & Current Waveforms

36. P-Q WAVEFORMS

37. INVERTER VOLTAGE WAVEFORM

38. THD FOR GRID VOLTAGE IN PHASE A

39. THD FOR GRID CURRENT IN PHASE A

40. THD FOR INVERTER VOLTAGE IN PHASE A

41. THD FOR INVERTER CURRENT IN PHASE A

42. LL FAULT

43. GRID VOLTAGE & CURRENT WAVEFORMS

44. P-Q WAVEFORMS

45. INVERTER VOLTAGE WAVEFORM

46. THD FOR GRID VOLTAGE IN PHASE A

47. THD FOR GRID CURRENT IN PHASE A

48. THD FOR INVERTER VOLTAGE IN PHASE A

49. THD FOR INVERTER CURRENT IN PHASE A

50. LLG FAULT