الملخص الإنجليزي
The importance of solar photovoltaic (PV) systems has grown significantly with
the continuous and rapid development of the solar cells industry over the past
years. Grid-connected solar PV systems provide a number of benefits to power
distribution systems such as cost-effectiveness of solar panels and inverters,
environmentally friendly output of the system as well as its easy installation and
minimal maintenance requirements.
However, the continuous growth of solar PV systems in existing distribution
networks has raised new concerns due to the potential impacts such as on
technical power losses and power quality. These impacts are also affected by PV
system output variability. Studying the potential impacts of solar PV systems on
the distribution network has recently become a significant topic with high
attention. This research presents an overview of the potential impacts of solar PV
systems integration on the Petroleum Development Oman (PDO) - Mina AlFahal (MAF) distribution network including technical losses, power quality and
PV system output variability under different penetration levels and weather
conditions. Furthermore, recommendations to mitigate the potential impacts on
PV solar systems distribution networks are also presented.
The technical losses analysis has been performed by using Load Flow analysis
and Quasi-Dynamic time domain simulation with DIgSILENT® simulation
software. It was observed that the solar PV systems can reduce technical losses
when located close to load centers and when the solar PV output power is less
than the power demand required by the end user where no reverse power occurs.
Beyond a specific level, any increase in the solar PV capacity may result in an
increase of system losses due to increased reverse power flow.
In addition, investigations of the power quality issues using measurements have
been performed. It was found that the measured voltage unbalance and THD
levels were within the limits stated by the distribution code in Oman.
Furthermore, the evaluation of voltage flickers showed some violations of the
limits specified by the distribution code and thus, required closer system
monitoring.
The wide-scale integration of the solar PV power might bring concerns regarding
PV output variability and its challenges to distribution networks. Aggregating the
output of different PV systems can reduce the negative implications of such
variability on the grid. Different scenarios were considered to study the
smoothing effect of aggregating the output of solar PV systems on output
variability. As cloud fronts do not cover different PV plants simultaneously, the
aggregated PV system output is less variable than that from a single PV system.
The study demonstrates that the smoothing effect is dependent on the number as
well as the geographical diversity of PV systems.
