Citation: Abbas, A.; Qaisar, S.M.; Waqar, A.; Ullah, N.; Al Ahmadi, A.A. Min-Max Regret-Based Approach for Sizing and Placement of DGs in Distribution System under a 24 h Load Horizon. Energies 2022, 15, 3701. https://doi.org/10.3390/en15103701 Academic Editor: Abu-Siada Ahmed Received: 23 April 2022 Accepted: 16 May 2022 Published: 18 May 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 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 Min-Max Regret-Based Approach for Sizing and Placement of DGs in Distribution System under a 24 h Load Horizon Asad Abbas 1 , Saeed Mian Qaisar 2,3 , Asad Waqar 4, * , Nasim Ullah 5 and Ahmad Aziz Al Ahmadi 5, * 1 Department of Electrical Engineering, Chungnam National University, Daejeon 34134, Korea; asadabbasturi.engr@gmail.com 2 College of Engineering, Effat University, Jeddah 22332, Saudi Arabia; sqaisar@effatuniversity.edu.sa 3 Communication and Signal Processing Lab, Energy and Technology Center, Effat University, Jeddah 22332, Saudi Arabia 4 Department of Electrical Engineering, Bahria University, Islamabad 44000, Pakistan 5 Department of Electrical Engineering, College of Engineering, Taif University, Taif 21944, Saudi Arabia; nasimullah@tu.edu.sa * Correspondence: asadwaqar.buic@bahria.edu.pk (A.W.); aziz@tu.edu.sa (A.A.A.A.) Abstract: Load variations in any power system result in loss escalation and voltage drops. With the sensible and optimal allocation of distributed generators (DGs), these problems could be considerably mitigated. It has been seen in existing methods that, ideally, the allocation of DGs has been carried out during fixed loads and constant power requirements. However, in real scenarios the loads are always variable and the allocation of DGs must be done in accordance with the variations of the connected load. Therefore, the current paper addresses the aforementioned problem by the distinctive optimal allocation of DGs for each variability of 24 h load horizon. However, a single exclusive solution is considered among all allocations of 24 h. The min-max regret concept has been utilized in order to deal with such a methodology. Altogether, 24 scenarios are analyzed wherein each scenario corresponds to a specific hour of the respective day. The optimal allocation of DGs in terms of their optimal sizing and placement has been carried out by using three algorithms including battle royale optimization (BRO), accelerated particle swarm optimization (APSO), and genetic algorithm (GA). The multi-objective optimization problem is evaluated on the basis of minimum value criterion of the multi-objective index (MO). MO comprises active and reactive power losses and voltage deviation. Hence, in order to find the robustness of the proposed technique, Conseil international des grands reseaux electriques’ (CIGRE) MV benchmark model incorporating 14 buses has been used considerably as a test network. In the end, the results of three proposed algorithms have been compared. Keywords: distributed generators; sizes and locations of DGs; DGs’ allocation; power losses; min-max regret criteria; battle royale optimization 1. Introduction The invention of electricity and advancement in technology has brought remarkable improvements to mankind [1]. In electrical systems, transmission and distribution networks are the most significant operators. The distribution networks comprise a complex and engaged system. Therefore, the poor performance of the distribution networks may deprive the whole power system. One of the major hurdles to the performance marker of a distribution network is load variations over time. These load variations lead to varying active and reactive power losses and voltage drops [2]. One of the significant methods is the optimal deployment of DGs to minimize the power losses and improve the voltage drops in the distribution networks [3]. These DGs could be fossil fuel-based or renewable energy-based. Furthermore, the deployment of DGs in networks brings on significant Energies 2022, 15, 3701. https://doi.org/10.3390/en15103701 https://www.mdpi.com/journal/energies