IEEE Power Electronics Magazine - March 2022 - 34

in efficiency of the system. These conditions call for
critical countermeasures in order for the generating system
to sustain in such situations and simultaneously
power the load without any alterations. Given there is
no feasible method to ward off these adverse conditions,
the best way to restore the power system back to
its nominal operating state is to detect and neutralize
any faults on a panel. Traditional methods to mitigate
the damage being caused by these adverse conditions
include the utilization of by-pass diodes to protect the
SPV panels from hotspots and to improve efficiency. But
in typical solar farms, these by-pass diodes reduce the
performance of the whole system causing a significant
drop in efficiency.
Several methods have been proposed to identify bypassed
modules but most of these methods involve direct
and indirect manual interactions, which take place periodically.
This means the module operates in low power conditions
for a longer time. The proposed method presents a new
approach to identify faults incorporating the concepts of isolated
circuits driven by forward voltage, influencing the panel
performance in an enormously positive sense. When the bypass
diode is activated under low insolated conditions, the
forward voltage developed across the diode drives the input
of the optocoupler which triggers an inversion of the optocoupler
output voltage. This change in voltage raises an alert
via a communication module connected at the output port of
the optocoupler. This method provides a solution to two of
the most crucial aspects in any system, time and energy, with
IPV
BD1
BD2
BDn
Shading Due to
Cloud/Dust/Mist/
Leaves/etc.,
P1
BP1
VOC
P2
BP2
P2
BP2
VPV
P1
BP1
BD1
BD2
the entire equipment costing nothing more than 20 USD for
at least 10 panels in an array. The immediate response of the
model proposed triggers an almost immediate action against
the aforementioned faults, impacting the system immensely
and saving a lot of power in low efficient environments such
as photovoltaic systems. Offering an improvement in efficiency
with extremely low manufacturing costs, this design
can be considered as a method having a very positive impact
on a commercial level for SPV systems. The proposed system's
validity has been verified through hardware tests, and
the results and analyses of which are presented in the article,
supporting this claim.
Partial Shading and Faulty Panels
SPV systems offer one of many, if not the best alternative to
traditional power sources. The operational theories of the
two power sources, conventional and renewable, when juxtaposed,
presented a major difference in the efficiencies of
these systems. SPV systems offered extremely low efficiencies
in comparison with traditional power sources. There
have been significant advancements in the manufacturing
sector, which aided in improving the efficiency of these systems
to almost 23% in 2019 [1], which, albeit very low, is a
commendable improvement from the efficiencies of these
systems a decade ago.
When the irradiation on the module is partially
obstructed by an external spatial entity, the panel is said
to be operating under partial shading conditions as shown
in Figure 1. Under these conditions, the photon energy
IPV
BDn
Pn
Pn
BPn
BPn
(a)
(b)
FIG 1 Structure of a PV panel in a solar PV farm. (a) All panels in the array are healthy. (b) One panel in the array partially shaded.
34 IEEE POWER ELECTRONICS MAGAZINE z March 2022

IEEE Power Electronics Magazine - March 2022

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