University of Mohaghegh ArdabiliJournal of Operation and Automation in Power Engineering2322-457614220260401Radial Distribution System Network Reconfiguration for Reduction in Real Power Loss and Improvement in Voltage Profile, and Reliability7885295310.22098/joape.2024.14549.2113ENShrunkhalaHalveDepartment of Electrical Engineering, Gokhale Education Society R.H.Sapat COEMS and R, Nashik, India.SantoshRaghuwanshiDepartment of Electrical Engineering, Medi-Caps University, Indore, India.DeepakSonjeDepartment of Electrical Engineering, GESRH Sapat College of Engineering and Management Studies, Nashik, Maharastra, India.Journal Article20240130Distribution systems play a crucial role in delivering power to customers and bridging the gap between bulk power transmission and end-users. Increasing energy demand due to factors like industrial development and population growth necessitates efficient distribution system management. A low X/R ratio in distribution networks leads to higher real power losses, lower voltage profiles, and reduced system reliability. Selecting optimal combinations of sectionalizing and tie switches for network reconfiguration is a complex and time-consuming task. This article introduces the Modified load flow (MLF) method, which combines the backward/forward sweep method with an effective approach for selecting sectionalizing and tie switches to minimize real power loss. The MLF method offers advantages such as ease of implementation, requiring fewer control parameters, and scalability to large distribution systems. The proposed MLF method is compared with particle swarm optimization (PSO) and other existing algorithms in literature such as the cuckoo search algorithm (CSA), Improved sine cosine algorithm (ISCA), and Improved harmony search algorithm (IHSA). Results obtained from MLF and PSO to IEEE-33, 69, and 118 bus radial distribution systems demonstrate significant reductions in real power loss, with MLF outperforming PSO in terms of efficiency and effectiveness. Voltage profiles at critical buses before and after network reconfiguration are examined, showing improvements in MLF better than the PSO method. Various reliability indices are evaluated to assess system performance before and after network reconfiguration, demonstrating improvements in system reliability. Overall, the proposed modified load flow method offers a promising approach to address the challenges of real power losses and system reliability in radial distribution systems.https://joape.uma.ac.ir/article_2953_da25116ed6f962fd48cab4149b977050.pdfUniversity of Mohaghegh ArdabiliJournal of Operation and Automation in Power Engineering2322-457614220260401Operation Studies of Power Systems Containing Wind Farms Considering both Deterministic and Probabilistic Reliability Criteria8694299310.22098/joape.2024.14839.2135ENAmirGhaediDepartment of Electrical Engineering, Dariun Branch, Islamic Azad University, Dariun, Iran.RezaSedaghatiDepartment of Electrical Engineering, Beyza Branch, Islamic Azad University, Beyza, Iran.MehrdadMahmoudianDepartment of Electrical Engineering, Apadana Institute of Higher Education, Shiraz, Iran.Journal Article20240324In many different nations around the world, renewable energy sources are increasingly being used to generate electricity. It is because renewable resources are sustainable, have no operating costs, and are environmentally friendly. Wind power develops quickly among renewable units, and nowadays, several wind farms with large installed capacity are operating in the world. However, the erratic property of wind velocity causes generated power of wind parks to vary, which has an impact on various parts of electric network connected to wind parks and needs to be studied using new methods. In order to address reliability-based operation studies of electric network in presence of wind parks, the current research suggests a method taking into account both probabilistic and deterministic approaches for reserve scheduling. The PJM method has been modified for this reason, for incorporating wind production into the electric network. For wind farms, a several-state reliability presentation that considers hazard of assembled elements and change in produced power is developed at first stage. The appropriate amount of spinning reserve is then computed using matrix multiplication method through modified PJM methodology. Numerical simulations related to reliability test networks are provided for assessing efficacy of suggested methodology. It is concluded from numerical outcomes that the wind farms lead to the reduction of required spinning reserve. However, due to the variation of output power of wind farms arisen from variation of wind velocity, the impact of wind units in reduction of spinning reserve is less than the conventional units with the same capacity. Besides, spinning reserve calculated by well-being approach of wind farms that combines the probabilistic and deterministic indices is more accurate than the value obtained by risk indices.https://joape.uma.ac.ir/article_2993_b78c2aa84dd5c61e4713e1f775fc6abe.pdfUniversity of Mohaghegh ArdabiliJournal of Operation and Automation in Power Engineering2322-457614220260401Analysis and Implementation of a High Step-Up DC-DC Converter Integrating a Hybrid Voltage Multiplier Cell and a Coupled Inductor95105306410.22098/joape.2024.15060.2149ENHosseinShayeghiEnergy Management Research Center, University of Mohaghegh Ardabili, Ardabil, Iran.RezaMohajeryEnergy Management Research Center, University of Mohaghegh Ardabili, Ardabil, Iran.NicuBizonThe National University of Science and Technology Politehnica Bucharest, Pitești, University Centre, 110040 Pitesti, Romania.Journal Article20240512This research introduces a modified design for non-isolated DC-DC converters with a high voltage gain using the design concepts of a coupled inductor (CI) and a hybrid voltage multiplier cell. It is attainable to further increase the output gain without requiring a higher duty cycle or a large turn ratio of CI. This means that the power switch won't be under too much voltage stress. The suggested converter's important features are low maximum voltage across all semiconductor components, considerable efficiency, and a substantial voltage conversion ratio. In addition, the suggested topology includes diodes with soft switching conditions, which allows for a reduction in reverse recovery losses and an improvement in system efficiency. The proposed topology includes input current continuity, a single power switch, and a common ground between the source and the load. Operating analysis, theoretical definitions, efficiency investigation, and a literature review of comparable structures have been considered to demonstrate the proposed structure's functionality. An experimental prototype has also been established, featuring 115V output voltage, 20V input voltage, and 40kHz switching frequency, to facilitate the assessment of the proposed converter's efficacy.https://joape.uma.ac.ir/article_3064_d938456aca96c7fa9d7fc3c6c351aee4.pdfUniversity of Mohaghegh ArdabiliJournal of Operation and Automation in Power Engineering2322-457614220260401A Voltage Multiplier Based DC-DC Converter with Reduced Switch Stress and Ultra-High Voltage Gain106113338310.22098/joape.2024.14785.2133ENAhmadrezaGhanaatianDepartment of Electrical Engineering, Iran University of Science and Technology, Tehran, Iran.0009-0002-6300-6728RezaTakarliDepartment of Electrical Engineering, Iran University of Science and Technology, Tehran, Iran.AbolfazlVahediDepartment of Electrical Engineering, Iran University of Science and Technology, Tehran, Iran.Journal Article20240311A novel interleaved non-isolated high-gain topology is presented in this article. This converter reaches its significant gain by combining two voltage multiplier cells (VMCs), a built-in transformer (BIT) with two windings, and coupled inductors (CIs) with two windings. Leakage inductance energy recovery, reduction of input current ripple, flow sharing by interleaved technique, increased flexibility in design by improving the conversion ratio of built-in transformer and coupled inductance, power masts turned on under zero current switching (ZCS), also switched off for Diodes are features of this topology. A voltage of 20V was applied to the simulated topology. As a result, a load output voltage of 533V was achieved, and an output power of 320 watts was generated.https://joape.uma.ac.ir/article_3383_f6c34920b183c23efd692910ac4f7950.pdfUniversity of Mohaghegh ArdabiliJournal of Operation and Automation in Power Engineering2322-457614220260401Development and Optimization of High-Power and Medium-Voltage Battery Energy Storage System Based on CHB Converter114122349110.22098/joape.2024.13040.1989ENMousaRajabi VandchaliFaculty of Electrical and Computer Engineering, Babol Noshirvani University of Technology, Babol, Iran.HodaGhoreishyFaculty of Electrical and Computer Engineering, Babol Noshirvani University of Technology, Babol, Iran.MahdiShahparastiSchool of Technology and Innovations, Flexible Energy Resources, University of Vaasa, 65200 Vaasa, Finland.Journal Article20240429Battery energy storage systems have become an integral part of electrical systems in various applications, including stabilizing and increasing the reliability and efficiency of utility grids, and they play an essential role in directly injecting the power generated from renewable sources into the grid. Therefore, investigating and conducting extensive research on various aspects of BESS, such as development, optimization, production, and installation, is essential. One of the challenges of using low-voltage BESS for medium-voltage and high-power applications is that, since two and three-level converters are not able to generate high voltage and also inject high power into the utility grid, it is necessary to utilize step-up transformers, which apart from being bulky, large and expensive, also cause damage to the system. Therefore, multi-level topologies are needed. Hence; this paper describes the development process of a 20-kV and 8-MW BESS based on a cascaded H-bridge converter with a focus on optimization of the most crucial system parameters, including switching loss in semiconductors, LCL filter, and DC-link capacitor by using Pareto Front method to minimize the overall loss, which leads to better performance and high efficiency. To verify the proper performance of the control strategy and evaluation of output results, the optimized system has been simulated in MATLAB/SIMULINK, and the system waveforms have been presented and discussed.https://joape.uma.ac.ir/article_3491_e830025885c2ffefdb1415e2e2c710e6.pdfUniversity of Mohaghegh ArdabiliJournal of Operation and Automation in Power Engineering2322-457614220260401Predicting Electrical Load Demand Using Bagging Ensemble of Multi-Layer Perceptron and Adjusted Long Short-Term Memory with Metaheuristic Methods123130411910.22098/joape.2025.15471.2187ENSomayehTalebzadehDepartment of Information Technology Management, Science and Research Branch, Islamic Azad University, Tehran, Iran.RezaRadfarDepartment of Information Technology Management, Science and Research Branch, Islamic Azad University, Tehran, Iran.AbbasToloie EshlaghyDepartment of Information Technology Management, Science and Research Branch, Islamic Azad University, Tehran, Iran.0000-0001-6050-1016Journal Article20240717Effective prediction of electric power demand is critical for maintaining the stability and reliability of the energy supply in both residential and industrial sectors. Accurate energy demand forecasting is essential for balancing consumption needs with grid stability. However, the complexity of energy consumption data, influenced by a variety of factors, makes this forecasting challenging. Traditional methods often struggle to capture the intricacies of such complex data, highlighting the need for more advanced and adaptable approaches. In this research, we propose a novel solution based on a Bagging ensemble of Multi-Layer Perceptron (MLP) and Long Short-Term Memory (LSTM) networks, combined through a voting mechanism to improve the accuracy and generalization ability of the model. Metaheuristic methods, including Particle Swarm Optimization (PSO) and the Genetic Algorithm (GA), are employed for optimal hyperparameter tuning of the LSTM. Unlike many existing studies that rely on proprietary or limited datasets, this approach uses publicly available data from the Electric Power Consumption dataset of Tetouan city (01-01-2017 to 12-31-2017), making it more accessible and applicable to broader contexts. It also enhances prediction performance by combining the results of multiple models, allowing for a more robust and accurate prediction of energy consumption. Experimental results demonstrate that the proposed approach significantly outperforms existing machine learning and deep learning methods.https://joape.uma.ac.ir/article_4119_871ea8415988cb113224e600cd10f075.pdfUniversity of Mohaghegh ArdabiliJournal of Operation and Automation in Power Engineering2322-457614220260401Robust Control Design for Voltage and Frequency Fluctuation Control under Substantial Load Variation of Islanded Microgrid System131141356610.22098/joape.2024.14841.2136ENOinam ManganleibaMeeteiDepartment of Electrical Engineering, Manipur Technical University, Imphal, Manipur- 795004, India.MarimuthuPrakashDepartment of Electrical and Electronics Engineering, National Institute of Technology, Nagaland, Chumukeidma- 797103, India.RajagopalKumarDepartment of Electronics and Instrumentation Engineering, National Institute of Technology, Nagaland, Chumukeidma- 797103, India.Journal Article20240325The use of standalone microgrids is rapidly increasing due to their advantages in terms of environmental, economic, and technical aspects. However, the microgrid is vulnerable to frequency and voltage oscillation because of its separation from the main grid, the uncertainties of loads, and the use of uncertain renewable energy sources such as wind and solar energy. Therefore, the need for a dynamic controller arises to regulate voltage and frequency. This paper presents Double Integral Sliding Mode Control (DISMC) and Artificial Neural Network (ANN) based on the Feed Forward Bayesian Regularization (FF-BR) algorithm. DISMC is developed to control voltage and steady-state error. The ANN based on the FF-BR algorithm is adapted to regulate the current. These controllers enhance the performance of droop control for inverter base Distributed Generation (DG) units in an islanded microgrid system. The controllers are designed based on the islanded microgrid dynamic model and load variations. The suggested control algorithm is implemented in Matlab/Simulink. The performance of the controller is evaluated under variable loads and uncertainties. The results are then compared with droop control with the Proportionate Integral (PI) controller. The performance of the proposed controllers is seen to outdo the existing PI method in the regulation of voltage and frequency.https://joape.uma.ac.ir/article_3566_2e5f667525fc60445d1dd6dc1a5a5ceb.pdfUniversity of Mohaghegh ArdabiliJournal of Operation and Automation in Power Engineering2322-457614220260401Improving the Resiliency of Electrical Distribution Networks by Optimal Embedding Switchable Capacitor Banks in Microgrids Based on a Convex Model142153352110.22098/joape.2024.15405.2180ENHesam AddinYousefianDepartment of Electrical Engineering, University of Zanjan, Zanjan, Iran.AbolfazlJalilvandDepartment of Electrical Engineering, University of Zanjan, Zanjan, Iran.AmirBagheriDepartment of Electrical Engineering, University of Zanjan, Zanjan, Iran.Journal Article20240706The importance of durability and sustainability in electrical energy, particularly in emergency conditions, has led to the development of operational techniques aimed at improving the serviceability of electrical distribution networks (EDNs). Operating the electrical distribution network as a smaller, islanded system in the form of a microgrid (MG) is one of the key enhancement methods that has gained attention. Each microgrid is subject to specific constraints that must be addressed. Moreover, the increasing penetration of renewable distributed generation (DG) units introduces additional limitations. The limited reactive power generation by synchronous DGs within each MG leads to higher levels of load shedding. This paper investigates the resiliency of EDNs with a focus on microgrid formation strategies. To achieve this, the limitations of MG formation, including the use of wind turbines, photovoltaic units as renewable DGs, and energy storage systems, are considered. The application of switchable capacitor banks (SCBs) is proposed and formulated to meet these requirements. All equations are convex and formulated within the GAMS environment using mixed-integer quadratically-constrained programming (MIQCP). The proposed framework is evaluated using the IEEE 69-node test system, considering various case studies. The results show that the economic deployment of SCBs in the MG formation of the studied EDN leads to a reduction of the objective function by approximately 13.6%, a loss reduction of about 26.1%, and a significant increase in the penetration of renewable resources by 285.6%.https://joape.uma.ac.ir/article_3521_99e27e4cd953bb685689dc8b1b884f9b.pdf