energies
Article
System Parameter Based Performance Optimization of Solar
PV Systems with Perturbation Based MPPT Algorithms
Sachin Angadi
1,*
, Udaykumar R. Yaragatti
2
, Yellasiri Suresh
2
and A. B. Raju
1
Citation: Angadi, S.; Yaragatti, U.R.;
Suresh, Y.; Raju, A.B. System
Parameter Based Performance
Optimization of Solar PV Systems
with Perturbation Based MPPT
Algorithms. Energies 2021, 14, 2007.
https://doi.org/10.3390/en14072007
Academic Editor: Eun-Chel Cho
Received: 5 January 2021
Accepted: 24 February 2021
Published: 5 April 2021
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4.0/).
1
Department of Electrical and Electronics Engineering, K.L.E Technological University, Hubli 580031, India;
abraju@kletech.ac.in
2
Department of Electrical and Electronics Engineering, National Institute of Technology—Karnataka,
Surathkal 575025, India ; udaykumarry@yahoo.com (U.R.Y.); ysuresh.ee@gmail.com (Y.S.)
* Correspondence: sachin@kletech.ac.in
Abstract: Maximum power point tracking (MPPT) algorithms are invariably employed to utilize solar
photovoltaic (PV) systems effectively. Perturbation based MPPT algorithms are popular due to their
simplicity and reasonable efficiency. While novel MPPT algorithms claim increased energy utilization
over classic perturbation techniques, their performance is governed by the choice of optimal algorithm
parameters. Existing guidelines for parameter optimization are mathematically laborious and are not
generic. Hence, this paper aims to provide simple and comprehensive guidelines to ensure optimal
performance from the perturbation based MPPT technique. For an illustration of proposed claims,
a solar PV fed boost converter is investigated to examine the effect of input capacitor, digital filter
cut-off frequency, system time constant and sampling time on implementing a classic Perturb and
Observe (P and O) algorithm. The readers will be presented with two simple step tests (to determine
the effective system time constant) and proposed guidelines to choose the optimal performance
sampling time. Necessary laboratory experiments show that an appropriate choice of sampling time
could increase efficiency and ensure system stability. This investigation’s learnings can be easily
extended to any power electronics converter, loads and all perturbation-based algorithms used in
solar PV systems. The results of appropriate tests on the system’s mathematical model and the
laboratory prototype are presented in detail to support this research’s claims.
Keywords: boost converter; maximum power point tracking (MPPT); perturb and observe algorithm;
renewable energy; solar photovoltaic system
1. Introduction
To meet growing energy needs, it is inevitable that renewable technology will be
adopted for energy decarbonization. Solar photovoltaic (PV) power is foreseen to mature
as the world’s largest electricity source by 2050 with the current potential in the range of
1575–49,837 exajoules [1]. The available solar energy can be harnessed in standalone or
grid-connected mode. Irrespective of the application of solar PV systems, the maximum
power point tracking (MPPT) algorithm is mandatory to ensure optimal power extraction
from the solar PV system due to non-linear P-V (power-voltage) characteristics.
The Solar PV system’s P-V curve exhibits a non-linear characteristic with only one
peak power operating point. The system operates at this Maximum Power Point (MPP)
when source impedance matches load impedance [2]. Perturbation techniques are popular
for achieving MPP due to factors like minimal sensors and ease of implementation [3].
System variables like duty ratio (D), PV voltage (V
pv
) and PV current ( I
pv
) are continu-
ously perturbed to force the system to operate at MPP against disturbances like changing
irradiances and loads [4]. Research in perturbation-based MPPT has evolved in two folds,
namely novel algorithms and optimization of system parameters.
Novel algorithms include classic algorithms like Perturb and Observe (P and O)
method and Incremental Conductance (InC) method. Also, research is fast emerging
Energies 2021, 14, 2007. https://doi.org/10.3390/en14072007 https://www.mdpi.com/journal/energies