The ultimate component of photovoltaic energy conversion into electrical
power is the solar cell. The best efficiency of this conversion is obtained
for a group of few cells in parallel or in series, forming what is called ?a
solar module?. This grouping requires special precautions in order to avoid
panel degradation, occurring when the amount of incident radiation received
by a photovoltaic module is not the same (Shading Effect). This results in a
dispersion of cell parameters, some cells become resistive and heat up (hot
spots), thus producing significant power dissipation and reducing the
characteristics of the PV module. In order to preserve the solar panel and
lessen the shadow affect, bypass diodes are utilized. In the present
research, a Matlab/Simscape model is used to plot I-V and P-V panel
characteristics, under different numbers of shaded cells, with and without
bypass diodes to illustrate the effects of partial, total and random shading
on the PV module performance. Furthermore, our aim is to show how adding
bypass diodes changes the performance of a partially shaded solar system.
Experimental tests were carried out within the Fr?res Mentouri Constantine 1
University of Constantine / Electrical Engineering Laboratory (LEC) in order
to study the effects of total, partial and non-uniform shading of mono
crystalline silicon photovoltaic module (80W) with 36 cells connected in
series (every 18 cells in the panel have one bypass diode). The obtained
experimental data indicate that the PV module power decreases up to almost
50% in case of full shading, and up to 30% in case of application of partial
shading.