1. PRESENTED BY SUDHEESH.S PS-B-12

2. CONTENTS  INDTRODUCTION  WIND POWER EXTRACTION WITH BATTERIES  CONTROL SCHEME  SYSTEM PERFORMANCE  RESULTS  CONCLUSION  REFERENCES 2

3. INTRODUCTION  Traditional energy sources.  Importance of micro wind power generation.  Sensitive electronic components and critical loads needs good quality power.  Power quality of micro wind power generation.  Lead acid battery cell for energy storage.  Energy saving and un-interruptible power.  Current controlled voltage source inverter is used for the interfacing between battery with microwind generator into the distributed netwok. 3

4. Micro-Wind Energy Generating System 4 Fig. 1

5. 5 T mech =P mech / ω turbine P mech =C p P wind P wind = ½ πρR²V³ wind P wind = ½ πρR²V³ wind C p 2 1 3 4 Micro-Wind Energy Generation ------------------------ ------------------------- -----------------------

6. Advantages Unity power factor and power quality. Real and reactive power support. Stand-alone operation in case of grid failure. Harmonics reduction. Reduction in CO 2 production. 6

7. Power-speed characteristics 7 Fig. 2

8. Dc Link for Battery Storage 8 Fig. 3

9. 9 5 7 6 Design of dc link ------------------------ ------------------------------------------- -----------------------------------------------

10. Control Scheme of the System 10 Fig. 4

11. Dc link to extract energy from wind Ripples are avoided by using dc link Step up transformer and bridge rectifier for dc bus voltage Battery with micro-wind generator for critical load application The control scheme is based on injecting the current into the grid using “hysteresis current controller.” The reference current i ∗ Sabc and actual current i Sabc is measured from source phase a, b, c are compared and thus activate the operation of inverter 11

12. 12 Control scheme for switching the inverter circuit. Fig. 5

13. Grid Synchronization 13 8 10 9 --------------------------- -------------------------- ------------------

14. Reference Signal Generation Circuit 14 Fig. 6

15. Hysteresis Band Controller 15 The ON/OFF switching signals for IGBT i sa < (i ∗ sa − HB) → S A = 0 i sa > (i ∗ sa + HB) → S A = 1 Fig. 7

16. Why Hysteresis Band Controller? The source currents are harmonic free and their phase- angles are in-phase with respect to source voltage. The power transfer takes place as soon as battery energy system is fully charged. Hysteresis band current control is not expensive. The control is excellent for a fast response of an inverter to rapid changes of reference current. 16

17. 17

18. Dynamic Performance Under Power Quality Mode 18 (a) Source current. (b) Inverter injected current. (c) Load current. Fig. 8

19. Dynamic Performance Under Stand- Alone Mode 19 (a) Source current. (b) Load current. (c) Inverter-injected current. Fig. 9

20. Dc Link Performance 20 (a) DC link voltage. (b) Current supplied by battery. (c) Charging-discharging of dc link capacitor Fig. 10

21. Performance of PI Controller 21 G(s)=10/(s(0.008s + 1)) Realization and the performance of the controller Fig. 11

22. PI Controller It corrects the error between measured variable and set value. K p amplify the current error and K i process the corrected error. K p improves steady state accuracy, relative stability and also makes the system less sensitive to the parameter variations. Fast response 22

23. 23 Source current and source voltage at PCC. Fig. 12

24. Without inverter controller 24 (a) Source current. (b) FFT of source current. Fig. 13

25. With the inverter-controller 25 (a) Source current. (b) FFT of source current. Fig. 14

26. 26 Table 2

27. Active and Reactive Power Flow at PCC in Micro-Grid 27 Active and reactive power (a) at source, (b) load and (c) inverter. Fig. 15

28. 28 Fig. 16

29. Experimental Results of the Controller 29 Fig. 17

30. 30 Fig. 18. The output of the hysteresis band current controller act as the input clock to this circuit. IC 74123 is used to generate the time delay. The pulse duration is controlled by the selection of external resistance and capacitor values. Dead time in order to prevent short circuits The input clock for the circuit

31. CONCLUSION Exchange of real and reactive power support to the critical load. The hysteresis current controller is used to generate the switching signal for inverter in such a way that to cancel the harmonic current in the system. The scheme maintains unity power factors. Allow the real power flow during the instantaneous demand of the load. Rapid injection or absorption of reactive/real power flow in the power system 31

32. REFERENCES [1]. S. W. Mohod and M. V. Aware, “Grid power quality with variable speed wind energy conversion,” in Proc. IEEE PEDES, Dec. 2006, pp. 1–6. [2]. P. F. Ribeiro, B. K. Johnson, M. L. Crow, A. Arsoy, and Y. Liu, “Energy storage system for advance power applications,” Proc. IEEE, vol. 89, no.12, pp. 1744–1756, Dec. 2001.. [3]. P. F. Ribeiro, B. K. Johnson, M. L. Crow, A. Arsoy, and Y. Liu, “Energy storage system for advance power applications,” Proc. IEEE, vol. 89, no.12, pp. 1744–1756, Dec. 2001. 32

33. [4]. B. S. Borowy and Z. M. Salameh, “Dynamic response of a stand-alone wind energy conversion system with battery energy storage to a windgust,” IEEE Trans. Energy Conversion, vol. 12, no. 1, pp. 73–78, Mar.1997. [5]. D. Graovac, V. A. Katic, and A. Rufer, “Power quality problems compensation with universal power quality conditioning system,” IEEETrans. Power Delivery, vol. 22, no. 2, pp. 968–997, Apr. 2007.. [6]. Z. Chen and E. Spooner, “Grid power quality with variable speed wind turbines,” IEEE Trans. Energy Conversion, vol. 16, no. 2, pp. 148–154, Jun. 2008.. 33

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