IEEE Power Electronics Magazine - September 2021 - 52

while Figure 7(b), Figure 7(c), and Figure 7(d) shows the
MPPT technique under different partial shading conditions.
In all, the irradiance scenarios, the proposed MPPT
method is capable of precisely identifying the MPP. This
method is also able to accurately differentiate the GMPP
from LMPPs. The MPPT technique was able to reach the
MPP within a single step in under 2 ms across all the different
test conditions.
The proposed MPPT method was observed over a
period of 30 days (15 March 2021-14 April 2021, location17.3850°
N, 78.4867° E) along with the conventional MPPT
technique mentioned in [3]. The energy extracted from
the conventional technique and the proposed scheme was
496.8 kWh and 546.48 kWh, respectively. From this result,
it is clear that almost 10% more energy was extracted using
the proposed scheme.
To further evaluate the MPPT performance of the proposed
AHM, the setup was examined under EN50530
dynamic test procedure [2]. Under these dynamic test
conditions, the MPPT efficiency was observed to be 100%.
These results verify the accuracy of the proposed method
for MPPT as well as I-V curve tracing.
Start
Switch ON G-3 for 0.1 ms, Switch OFF G-1 and G-2
Acquire the Voltage and Current Samples
From Isolated Voltage and Current Sensor
and Feed to 32 bit ADC
Perform Spline Interpolation
Calculate the Instantaneous Power and Obtain
the Maximum Power Point.
Find Respective Voltage and Current at
Which Maximum Power Point Occurs
Feed the Voltage and Current as a
Duty to Inverter/dc-dc Converter
Switch ON G-1, G-2 and Switch OFF G-3
Discharge the Capacitor With Minimal Possible Time
Discharge the Capacitor With Minimal Possible
Time by Controlling the G-2
Wait for 18-24 s and Repeat the Procedure
FIG 4 Single step MPPT algorithm for proposed AHM.
52 IEEE POWER ELECTRONICS MAGAZINE z September 2021
Current and voltage measurements are crucial for fault
detection and diagnosis methods in SPV systems [11].
Hence, the proposed AHM could be utilized in SPV research
for detecting a faulty/degraded/shaded panel in a SPV
string/array by instantaneously analyzing its overall I-V and
P-V characteristics. Such systems would bolster the SPV
system safety as well as the total energy production cycle
by lowering maintenance down time. However, fault detection
and monitoring applications of the proposed AHM are
beyond the scope of this article.
Conclusion
Accurate MPPT is crucial for the efficient operation of an
SPV system. This article presents a novel method utilizing
hardware alteration to achieve rapid MPPT in a single
step. A dynamic capacitor charging approach was
adopted for robust and rapid MPPT by tracing the I-V
curve of the SPV array. The proposed AHM was developed
as a hardware prototype and studied. The experimental
results of the setup under the EN50530 dynamic
test procedure established that this technology can precisely
locate the MPP. The MPPT accuracy of the set-up
held true even for different partial shading conditions;
this method was easily capable of differentiating GMPP
from LMPPs. For good measure, MPPT was executed in
a single step in under 2 ms without energy losses attributed
to oscillating around the MPP as seen in previous
MPPT techniques.
As a consequence of the above observations, utilizing
this new MPPT method is estimated to allow a SPV
system to harvest 10% more energy than with conventional
MPPT techniques. Plus, the option to tailor the
capacitor bank according to specific SPV system application
means that the proposed MPPT method offers a
high degree of flexibility and scalability; the additional
circuitry associated to this technology is also relatively
simple. The accuracy of the I-V curve tracer means
that the proposed scheme could also be implemented
in future SPV research for fault detection and monitoring
techniques systems by instantaneously observing
the P-V/I-V characteristics. One potential drawback of
the proposed MPPT method is that an AHM must be
installed. However, the approximate hardware cost for
the 4.6 kW lab scale setup was around $60 USD which
is quite small considering the increase in energy that is
obtained from the system.
Research and development in the field of SPV systems
is geared towards obtaining practical increments in SPV
system efficiency. By providing a straightforward improvement
in energy generation and efficiency, the proposed
MPPT technique achieves the goal.
Acknowledgment
This work was financially supported by the Department of
Science and Technology, Government of India, under project
number DST/TMD/CERI/RES/2020/10.
IEEE Power Electronics Magazine - September 2021

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