access icon free Effects of irradiance transition characteristics on the mismatch losses of different electrical PV array configurations

© The Institution of Engineering and Technology
Received 15/06/2016, Accepted 14/11/2016, Revised 22/09/2016, Published 15/11/2016

Photovoltaic (PV) systems are prone to irradiance fluctuations caused by overpassing cloud shadows which can be very large and steep. Cloud shadows have an average diameter of almost 1 km meaning that even the largest PV power plants are widely affected by them. Fast irradiance transitions can lead to failures in maximum power point tracking and to mismatch power losses due to partial shading of the PV generator. In this study, the effects of irradiance transition characteristics: shading strength, duration and apparent speed and direction of movement on the mismatch losses of PV generators were studied by simulations using a mathematical model of irradiance transitions and an experimentally verified MATLAB Simulink model of a PV module. The studied electrical PV array configurations were series–parallel, total-cross-tied and multi-string. Furthermore, three different physical shapes of the configurations were studied. On the basis of the results, module strings of PV arrays should be placed perpendicularly to the dominant apparent direction of movement of shadow edges and the diameter of the strings should be minimised to decrease the mismatch losses. Another finding of practical importance was that there were only minor differences between the mismatch losses of different electrical PV array configurations.

Inspec keywords: photovoltaic power systems; maximum power point trackers

Other keywords: MATLAB Simulink model; shadow edges; MPPT; total-cross-tied string; irradiance fluctuations; PV array configurations; photovoltaic power plants; cloud shadows; mathematical model; power losses mismatch; maximum power point tracking; multistring; irradiance transition characteristics; shading strength; series-parallel string; apparent speed

Subjects: Solar power stations and photovoltaic power systems; DC-DC power convertors

References

    1. 1)
      • 10. Mäki, A., Valkealahti, S.: ‘Mismatch losses in photovoltaic power generators due to partial shading caused by moving clouds’. Proc. 27th European Photovoltaic Solar Energy Conf., Frankfurt, Germany, September 2012, pp. 3911–3915.
    2. 2)
      • 13. Sánchez Reinoso, C.R., Milone, D.H., Buitgaro, R.H.: ‘Simulation of photovoltaic centrals with dynamic shading’, Appl. Energy, 2013, 103, pp. 278–289.
    3. 3)
      • 2. Patel, H., Agarwal, V.: ‘MATLAB-based modeling to study the effects of partial shading on PV array characteristics’, IEEE Trans. Energy Convers., 2008, 24, (1), pp. 302–310.
    4. 4)
      • 17. Tomson, T.: ‘Transient processes of solar radiation’, Theor. Appl. Climatol., 2013, 112, (3), pp. 403–408.
    5. 5)
      • 25. Wenham, S.R., Green, M.A., Watt, M.E., et al: ‘Applied photovoltaics’ (Earthscan, London, UK, 2007, 2nd edn.).
    6. 6)
      • 15. Tomson, T.: ‘Fast dynamic processes of solar radiation’, Sol. Energy, 2010, 84, pp. 318–323.
    7. 7)
      • 1. Lappalainen, K., Valkealahti, S.: ‘Analysis of shading periods caused by moving clouds’, Sol. Energy, 2016, 135, pp. 188–196.
    8. 8)
      • 3. Wang, Y.-J., Hsu, P.-C.: ‘An investigation on partial shading of PV modules with different connection configurations of PV cells’, Energy, 2011, 36, (5), pp. 3069–3078.
    9. 9)
      • 6. Villa, L.F.L., Picault, D., Raison, B., et al: ‘Maximizing the power output of partially shaded photovoltaic plants through optimization of the interconnections among its modules’, IEEE J. Photovolt., 2012, 2, (2), pp. 154–163.
    10. 10)
      • 18. Lappalainen, K., Valkealahti, S.: ‘Recognition and modelling of irradiance transitions caused by moving clouds’, Sol. Energy, 2015, 112, pp. 55–67.
    11. 11)
      • 12. Lappalainen, K., Mäki, A., Valkealahti, S.: ‘Effects of the sharpness of shadows on the mismatch losses of PV generators under partial shading conditions caused by moving clouds’. Proc. 28th European Photovoltaic Solar Energy Conf., Paris, France, September 2013, pp. 4081–4086.
    12. 12)
      • 21. Perez, R., Kivalov, S., Schlemmer, J., et al: ‘Parameterization of site-specific short-term irradiance variability’, Sol. Energy, 2011, 85, pp. 1343–1353.
    13. 13)
      • 4. Bidram, A., Davoudi, A., Balog, R.S.: ‘Control and circuit techniques to mitigate partial shading effects in photovoltaic arrays’, IEEE J. Photovolt., 2012, 2, (4), pp. 532–546.
    14. 14)
      • 20. Lave, M., Reno, M.J., Broderick, R.J.: ‘Characterizing local high-frequency solar variability and its impact to distribution studies’, Sol. Energy, 2015, 118, pp. 327–337.
    15. 15)
      • 23. Lappalainen, K., Valkealahti, S.: ‘Effects of irradiance transitions on the output power fluctuations of different PV array configurations’. Proc. IEEE Innovative Smart Grid Technologies – Asia Conf., Melbourne, Australia, November–December 2016, pp. 705–711.
    16. 16)
      • 14. Mäki, A., Valkealahti, S.: ‘Differentiation of multiple maximum power points of partially shaded photovoltaic power generators’, Renew. Energy, 2014, 71, pp. 89–99.
    17. 17)
      • 19. Lappalainen, K., Valkealahti, S.: ‘Apparent velocity of shadow edges caused by moving clouds’, Sol. Energy, 2016, 138, pp. 47–52.
    18. 18)
      • 16. Tomson, T., Hansen, M.: ‘Dynamic properties of clouds Cumulus humilis and Cumulus fractus extracted by solar radiation measurements’, Theor. Appl. Climatol., 2011, 106, (1), pp. 171–177.
    19. 19)
      • 11. Lappalainen, K., Mäki, A., Valkealahti, S.: ‘Effects of the size of PV arrays on mismatch losses under partial shading conditions caused by moving clouds’. Proc. 28th European Photovoltaic Solar Energy Conf., Paris, France, September 2013, pp. 4071–4076.
    20. 20)
      • 26. Torres Lobera, D., Mäki, A., Huusari, J., et al: ‘Operation of TUT solar PV power station research plant under partial shading caused by snow and buildings’, Int. J. Photoenergy, 2013, 2013, pp. 1–13.
    21. 21)
      • 8. Psarros, G.N., Batzelis, E.I., Papathanassiou, S.A.: ‘Partial shading analysis of multistring PV arrays and derivation of simplified MPP expressions’, IEEE Trans. Sustain. Energy, 2015, 6, (2), pp. 499–508.
    22. 22)
      • 7. Belhachat, F., Larbes, C.: ‘Modeling, analysis and comparison of solar photovoltaic array configurations under partial shading conditions’, Sol. Energy, 2015, 120, pp. 399–418.
    23. 23)
      • 9. Shams El-Dein, M.Z., Kazerani, M., Salama, M.M.A.: ‘Optimal photovoltaic array reconfiguration to reduce partial shading losses’, IEEE Trans. Sustain. Energy, 2013, 4, (1), pp. 145–153.
    24. 24)
      • 22. Lappalainen, K., Valkealahti, S.: ‘Mathematical parametrisation of irradiance transitions caused by moving clouds for PV system analysis’. Proc. 32nd European Photovoltaic Solar Energy Conf., Munich, Germany, June 2016, pp. 1485–1489.
    25. 25)
      • 5. Mäki, A., Valkealahti, S., Leppäaho, J.: ‘Operation of series-connected silicon-based photovoltaic modules under partial shading conditions’, Prog. Photovolt. Res. Appl., 2012, 20, (3), pp. 298–309.
    26. 26)
      • 24. Villalva, M.G., Gazoli, J.R., Filho, E.R.: ‘Comprehensive approach to modeling and simulation of photovoltaic arrays’, IEEE Trans. Power Electron., 2009, 24, (5), pp. 1198–1208.
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