Citation: Naidu, T.A.; Ali Ahmed Albeshr, H.M.; Al-Sabounchi, A.; Sadanandan, S.K.; Ghaoud, T. A Study on Various Conditions Impacting the Harmonics at Point of Common Coupling in On-Grid Solar Photovoltaic Systems. Energies 2023, 16, 6398. https://doi.org/10.3390/ en16176398 Academic Editors: Przemyslaw Otoma ´ nski and Dorota Stachowiak Received: 19 June 2023 Revised: 3 August 2023 Accepted: 5 August 2023 Published: 4 September 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). energies Article A Study on Various Conditions Impacting the Harmonics at Point of Common Coupling in On-Grid Solar Photovoltaic Systems Talada Appala Naidu * , Hamad Mohamed Ali Ahmed Albeshr , Ammar Al-Sabounchi, Sajan K. Sadanandan and Tareg Ghaoud Dubai Electricity and Water Authority (DEWA), Dubai P.O. Box 564, United Arab Emirates; hamad.albeshr@dewa.gov.ae (H.M.A.A.A.); ammar.munir@dewa.gov.ae (A.A.-S.); sajan.kaduvetty@dewa.gov.ae (S.K.S.); tareg.ghaoud@dewa.gov.ae (T.G.) * Correspondence: talada.naidu@dewa.gov.ae Abstract: Renewable penetration, particularly the increasing deployment of PV by residential cus- tomers, organizations, and utilities, is leading to the rapid evolution of the power grid. However, the power system’s architectural changes affect the quality of supply and give rise to power quality issues such as harmonics, fluctuations, disturbances, etc., at the point of common coupling (PCC). Therefore, in this work, a power network was modeled to study the impact of PV systems on PCC. At first, a detailed review is presented for on-grid PV systems with different inverter topologies, control techniques, sources of harmonic generation, and their mitigation strategies. After that, several use cases considering various sources of harmonics in a network with on-grid PV are modeled and simulated using MATLAB/Simulink. In-depth research was performed in this work to examine the many variables that affect harmonics, such as solar radiation levels, controller tuning, and load changes. Results with a real-time simulation platform (OPAL-RT) are presented in this paper for several use cases. Lastly, comprehensive discussions are presented from the acquired offline and real-time simulation results. Keywords: on-grid PV systems; power quality; PV inverter; harmonics; non-linear loads; mitigation methods 1. Introduction Solar photovoltaic (PV) demand is growing, as it has become the most cost-effective alternative for energy production in many areas, such as residential and commercial applications, utility-scale projects, etc. According to the Renewables global status report, all continents contributed substantially to the worldwide growth in the total capacity of renewables. Figure 1 depicts the global solar PV capacity and annual addition from 2010 to 2023 [1], which shows a 350 GW addition is projected in the year 2023 globally [2]. The fundamental goals of a power system are to create high-quality energy, transfer it efficiently, and provide it to customers for a reasonable price. The utility system must deliver energy to all consumers at the rated voltage magnitude and frequency [3]. Simulta- neously protecting the environment from the danger of gas emissions and decreasing the risk of global warming, the adoption of renewable energy technology has grown rapidly [4]. Also, it is essential for utilities to accomplish their primary objective, which is to transfer electricity as efficiently as possible from the generation plant to the end users [5]. To achieve the above requirements, PV technology has shown the highest potential for environmental friendliness, security, and effectiveness [6]. As a result, a high increase in PV penetration into the grid has been observed over the years [7]. PV systems with a suitable topology and filter configuration are generally connected to the grid using an inverter (DC/AC) at the point of common coupling (PCC). Because of the increased penetration of PV on the grid, Energies 2023, 16, 6398. https://doi.org/10.3390/en16176398 https://www.mdpi.com/journal/energies