Smoothing of Photovoltaic power production by plant dispersion
Pisapia, Amedeo (2017)
Pisapia, Amedeo
2017
Tieto- ja sähkötekniikan tiedekunta - Faculty of Computing and Electrical Engineering
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Hyväksymispäivämäärä
2017-09-04
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201709201917
https://urn.fi/URN:NBN:fi:tty-201709201917
Tiivistelmä
Power production by a (Photovoltaic) PV power plant is strongly dependent on the irradiance level that is incident on the panels thereof. By neglecting the sun’s variability that is precisely predictable, the main factor that influences the output power is the movement of the clouds over the plant. Therefore, such moving clouds lead to the presence of some fluctuations on the output power, that may influence the power quality and cause some problems of matching between the PV source and the load. In order to compensate such fluctuations, some Energy Storage Systems (ESS) are commonly used, but they need to be sized correctly. Many studies demonstrate that the solar variability impact on produced power is different if we consider a set of geographically dispersed systems, instead of single system. It has been noted a strong reduction in variability when the aggregation of several PV systems is taken into account, rather than just one single PV system. That is called “smoothing effect”.
In order to evaluate the output power of a single PV system, it was shown in literature that a PV system can be seen as a low-pass filter, due to its physical extension, where the input is the measured irradiance at a single point, and the output is a smoothed version of the single point irradiance, such filter output is proportional to the output power.
Other studies carried out how to evaluate the smoothing effect due to the geographical dispersions a distributed power plant. Using these methods, it is possible quantifying the reduction of variability associated with the dispersion of the plant over a region.
After having developed and validated a method to estimate the variability of a distributed power plant, the main objective of this master thesis has been to analyse the power output variability of a PV power plant by using the irradiance data measurements done in Tampere (Finland), considering different scenarios by changing the capacity and the number of subsystems that composes the power plant. This is done in order to compare the different layouts and understand how the smoothing effect depends on the plant size and on the geographical dispersion.
In order to evaluate the output power of a single PV system, it was shown in literature that a PV system can be seen as a low-pass filter, due to its physical extension, where the input is the measured irradiance at a single point, and the output is a smoothed version of the single point irradiance, such filter output is proportional to the output power.
Other studies carried out how to evaluate the smoothing effect due to the geographical dispersions a distributed power plant. Using these methods, it is possible quantifying the reduction of variability associated with the dispersion of the plant over a region.
After having developed and validated a method to estimate the variability of a distributed power plant, the main objective of this master thesis has been to analyse the power output variability of a PV power plant by using the irradiance data measurements done in Tampere (Finland), considering different scenarios by changing the capacity and the number of subsystems that composes the power plant. This is done in order to compare the different layouts and understand how the smoothing effect depends on the plant size and on the geographical dispersion.