https://escholarship.org/content/qt6w14r65n/qt6w14r65n.pdf?t=qeklbd

Verification of deterministic solar forecasts

Extensive comparison of physical models for photovoltaic power forecasting

Review of power system impacts at high PV penetration Part I: Factors limiting PV penetration

Harris hawk optimization-based MPPT control for PV systems under partial shading conditions

Assessment of the potential of different floating solar technologies – Overview and analysis of different case studies

Output power variation of different PV array configurations during irradiance transitions caused by moving clouds

Photovoltaic mismatch losses caused by moving clouds

A grid connected solar photovoltaic (PV) research facility equipped with comprehensive climatic and electric measuring systems has been designed and built in the Department of Electrical Engineering of the Tampere University of Technology (TUT). The climatic measuring system is composed of an accurate weather station, solar radiation measurements, and a mesh of irradiance and PV module temperature measurements located throughout the solar PV facility. Furthermore, electrical measurements can be taken from single PV modules and strings of modules synchronized with the climatic data. All measured parameters are sampled continuously at 10 Hz with a data-acquisition system based on swappable I/O card technology and stored in a database for later analysis. The used sampling frequency was defined by thorough analyses of the PV system time dependence. Climatic and electrical measurements of the first operation year of the research facility are analyzed in this paper. Moreover, operation of PV systems under partial shading conditions caused by snow and building structures is studied by means of the measured current and power characteristics of PV modules and strings.

/pdf/operation-of-tut-solar-pv-power-station-research-plant-under-1bh9gj0oot.pdf

Operation of TUT Solar PV Power Station Research Plant under Partial Shading Caused by Snow and Buildings

Recognition and modelling of irradiance transitions caused by moving clouds

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.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-rpg.2016.0590

Kari Lappalainen

Papers

Output power variation of different PV array configurations during irradiance transitions caused by moving clouds

Photovoltaic mismatch losses caused by moving clouds

Operation of TUT Solar PV Power Station Research Plant under Partial Shading Caused by Snow and Buildings

Recognition and modelling of irradiance transitions caused by moving clouds

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