Article
Engineering, Electrical & Electronic
Mohsen Tajdinian, Haidar Samet
Summary: The paper investigates the application of Probabilistic Distance Measure (PDM) in discriminating inrush and internal fault currents in power transformers, using Symmetric PDM to determine the discrepancy between the differential current signal and the reconstructed differential current waveform.
ELECTRIC POWER SYSTEMS RESEARCH
(2021)
Article
Automation & Control Systems
R. Vidhya, P. Vanaja Ranjan, N. R. Shanker
Summary: Continuous monitoring of transformer breather and CT through thermal imaging and radiometric pixels analysis helps detect and differentiate false tripping of differential protection system caused by inrush currents or internal faults.
INTELLIGENT AUTOMATION AND SOFT COMPUTING
(2023)
Article
Engineering, Electrical & Electronic
Hossein Ahmadi, Behrooz Vahidi, Amin Foroughi Nematollahi
Summary: The proposed method in this paper is based on creating a Delta V - I curve to detect and classify internal short-circuit faults in power transformers, using the finite element method to investigate the behavior of transformers in the presence of internal short-circuit fault, successfully applying the method to a distribution transformer with Yzn5 connection. Simulation results validate the capability of the proposed method in transformer monitoring.
ELECTRICAL ENGINEERING
(2021)
Article
Engineering, Electrical & Electronic
Priyanka Mishra, Amlan Swain, Ashok Kumar Pradhan, Prabodh Bajpai
Summary: This article proposes a technique for detecting transformer inrush using the decaying dc component in the negative sequence differential current. The method sets a threshold to differentiate internal faults and ensures blocking of the differential relay during inrush. The simulation results and field data testing validate the effectiveness of the proposed method with high-permeability transformer core.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Energy & Fuels
Othman Abdusalam, Alasmer Ibrahim, Fatih Anayi, Michael Packianather
Summary: A novel hybrid machine learning technique was proposed for the protection of three-phase power transformers. The developed model was tested using different fault conditions and types of current signal faults, and the signals were used to develop a hybrid model. Optimal feature identification was performed using orthogonal matching pursuit and discrete wavelet transform, and bees algorithm was used to optimize the dataset. Three classification algorithms were used to distinguish normal operational conditions from faults. The model was compared to a comparable approach using genetic algorithm and evaluated based on various performance metrics. The findings suggest that the proposed model is suitable for fault identification in a range of conditions and faults.
Article
Engineering, Electrical & Electronic
Bikash Patel, Parthasarathi Bera, Sunita Halder Nee Dey
Summary: The article proposes a new method to distinguish internal and external faults during power swing on the transmission line by determining the orientation of Lissajous figure of two terminal current signals. The method's performance is evaluated for various conditions and compared to available methods to prove its merit.
IEEE TRANSACTIONS ON POWER DELIVERY
(2021)
Article
Engineering, Electrical & Electronic
Bidhan Biswas, L. Satish
Summary: Mechanical winding damages in transformers are common but difficult to accurately represent or model. This paper proposes a simple method based on measured FRA and winding shunt capacitance to identify the phase undergoing radial displacement.
IEEE TRANSACTIONS ON POWER DELIVERY
(2023)
Article
Chemistry, Multidisciplinary
Shuguo Gao, Lu Sun, Yuan Tian, Hongliang Liu
Summary: This research provides theoretical support for the design and improvement of transformer winding resistance to a short circuit, and has certain guiding significance for real-time monitoring of transformer winding acceleration. It establishes a classical mass-spring-damping axial vibration mathematical model of transformer windings, takes into account the damping, stiffness, and mass parameters between windings, and quickly obtains the natural frequency, main mode shape, displacement, and acceleration of each wire cake of the multi-DOF vibration system. The relationship between the axial displacement and acceleration of the wire cake and the axial deformation of the transformer winding was discussed, and the characteristics of the transformer winding axis and vibration distribution were summarized.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Electrical & Electronic
Zexuan Lin, Songhao Yang, Yubo Zhang, Zhiguo Hao, Baohui Zhang
Summary: This paper proposes a data-aided power transformer differential protection method without inrush blocking module, which eliminates the negative influence of inrush current by extracting the fundamental component from the current waveform. Firstly, a data-aided module is built to distinguish the inrush and non-inrush parts of the current waveform, and then a physical model of the non-inrush part is established, and the fundamental component is extracted using the nonlinear least square algorithm. The proposed method can avoid the block of differential protection when inrush current occurs, improving the sensitivity and rapidity of the relay, especially in the case of a weak internal fault hidden in inrush current.
IEEE TRANSACTIONS ON POWER DELIVERY
(2023)
Article
Engineering, Electrical & Electronic
Anyang He, Zaibin Jiao, Zongbo Li, Yonghui Liang
Summary: This paper proposes a deep learning protection scheme based on a discriminative-feature-focused convolutional neural network to improve the accuracy of transformer protection and overcome the drawback of differential protection caused by inrush current. The proposed method extracts discriminative features of the unsaturated part of the differential current by using a specialized loss function and a three-module network design. The test results demonstrate that the proposed scheme accurately identifies transformer states with good robustness to noise and generalization to complex scenes, surpassing previous methods in reliability and generalization ability.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Engineering, Mechanical
Keith Pate, Israa Azzam, Farid Breidi, James R. Marschand, John H. Lumkes
Summary: Digital hydraulics is a rapidly developing technology that offers improved system efficiencies, energy savings, increased productivity, and system performance compared to traditional fluid power systems. This study focuses on the implementation of mechanically actuated valving systems in digital radial piston pumps, which have not been explored in prior research. The results show that these systems have high efficiencies across their displacement bandwidth but can still be further optimized. This research serves as the first step in designing an integrated mechanically actuated variable cam system in digital radial piston pumps.
Article
Engineering, Electrical & Electronic
Parvraj Pachore, Yugal Gupta, Sandeep Anand, Subrata Sarkar, Paresh Mathur, Pushpendra Kumar Singh
Summary: This paper presents a controlled switching technique to minimize inrush currents generated in a 3-phase transformer using gang operated circuit breakers. Optimum points for controlled closing and opening are obtained from a flux error function calculated from residual and prospective fluxes. Practical challenges and their solutions are discussed, and the proposed technique is validated through Controller Hardware-In-Loop (CHIL) and laboratory tests. Results show the effectiveness of the scheme in limiting inrush current, with further validation through a field test on a distribution transformer.
IEEE TRANSACTIONS ON POWER DELIVERY
(2021)
Article
Engineering, Electrical & Electronic
Amir Ameli, Mohsen Ghafouri, Hatem H. Zeineldin, Magdy M. A. Salama, Ehab F. El-Saadany
Summary: This article proposes an auxiliary framework for transformer differential protection, addressing challenges such as transformer or CT saturation, internal and cross-country faults detection, energizing faults detection, and inrush current detection without compromising sensitivity and speed of differential relays. The proposed method uses LPV state-space equations and observers to estimate transformer and CT states, accurately estimating primary currents to overcome CT saturation issues, and differentiating inrush currents from faults by comparing estimated and measured primary currents. Results of EMTP simulations demonstrate the effectiveness of this method.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2021)
Article
Engineering, Electrical & Electronic
Abdulrahman Alassi, Khaled H. Ahmed, Agusti Egea-Alvarez, Colin Foote
Summary: The increased use of inverters-based resources (IBRs) in power networks brings the need to revisit classical network operation standards. This paper investigates the energization techniques for transformers in inverters dominated grids and analyzes the feasibility of common techniques such as controlled switching and soft energization when used with grid-forming inverters. The study also examines the effects of parameters on soft energization voltage ramp-up time and explores the application limits of controlled energization using different circuit breakers in distribution networks.
IEEE TRANSACTIONS ON POWER DELIVERY
(2023)
Article
Energy & Fuels
Satoru Miyazaki
Summary: This paper investigates a method of detecting the axial displacement of power-transformer winding at an incipient stage without the need for fingerprint data. Resonances showing a bipolar signature in the transfer function of inductive interwinding measurement are analyzed, and a method of comparing amplitudes or patterns of these resonances is proposed. The method is applicable to three-phase transformers without fingerprint data, and its effectiveness is confirmed in a real transformer.
Article
Engineering, Electrical & Electronic
Nassim Shahbazi, Sajad Bagheri, Gevork B. Gharehpetian
Summary: This article introduces a new differential protection scheme for transformers, which is based on the self-adaptive biased characteristic curve and takes into account CCFs and various disturbances. By using the maximum overlap discrete wavelet transform and MATLAB software, a new self-adaptive biased characteristic curve is obtained and the differential protection operation is adjusted based on this curve. Simulation results show that this scheme can accurately detect various faults and events in transformers and improve system reliability.
INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Hamid Karimi, G. B. Gharehpetian, Roya Ahmadiahangar, Argo Rosin
Summary: This paper proposes a multi-objective optimization framework to improve the performance of demand response programs in distribution networks. The uncoordinated response of customers creates new peaks in the load profile when market prices are low, so the framework focuses on reducing operating costs and enhancing program efficiency. The model introduces the Average Power Flexibility during Peak Period Index (APFDPPI) to evaluate energy flexibility and simulation results show significant improvements compared to uncoordinated programs.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Automation & Control Systems
Mahdi Zolfaghari, Gevork B. B. Gharehpetian
Summary: This study presents a new platform for connecting multiple microgrids using a unified interphase power controller (UIPC), which would enable a system of systems with interconnected AC and DC microgrids to exchange power in a controlled manner. The UIPC is designed with a new structure based on a current-controlled four-leg power converter configuration to satisfy voltage and frequency support. Additionally, the UIPC is equipped with an affine projection-like optimal control (APLOC) strategy for managing power and voltage oscillations in the heterogeneous environment. Simulation results demonstrate the effectiveness of the proposed networked microgrids model in controlling power exchange and improving power quality.
IET CONTROL THEORY AND APPLICATIONS
(2023)
Article
Computer Science, Information Systems
Mohammad Saeed Mahdavi, Mohammad Saleh Karimzadeh, Tohid Rahimi, Gevork Babamalek Gharehpetian
Summary: This paper proposes a fault-tolerant topology and fault diagnosis algorithm for a bidirectional DC-DC converter in a BESS. The topology can detect open circuit faults and reconfigure the system to ensure safe and continuous operation. The fault diagnosis algorithm detects open circuit faults by observing the current of the inductors, eliminating the need for sensors and reducing the cost, weight, volume, and complexity of the system.
Article
Automation & Control Systems
Arya Hosseini, Amin Siahchehreh Badeli, Masoud Davari, Samad Sheikhaei, Gevork B. Gharehpetian
Summary: This article proposes a novel digital control method for low-power applications in multiple-input, single-inductor, multiple-output dc-dc converters. It utilizes stability analysis, time-multiplexing control method, and variable-frequency pulsewidth modulation to charge each output with different frequencies, while also implementing a digitally controlled zero-current switching technique for optimal inductor discharge duty cycle determination.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Industrial
Mehdi Akbari Moghadam, Sajad Bagheri, Amir Hosein Salemi, Mohammad Bagher Tavakoli
Summary: Distribution networks are challenging due to high number of customers and interruptions, requiring continuous and organized maintenance planning. This paper proposes an Extended Mixed-Integer Linear Formulation for long-term maintenance planning of overhead medium voltage distribution networks, considering uncertainties in the network and various constraints. The proposed method, implemented on a real network with 10 feeders in Markazi province of Iran, optimizes annual maintenance costs and improves network reliability by reducing interruptions.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2023)
Article
Engineering, Electrical & Electronic
Mostafa Khajavi, Sajad Bagheri, Asaad Shemshadi
Summary: In this study, the effects of the corona ring on the electric field intensity (EFI) distribution of the 230-kV composite insulator were investigated using the Finite Element Method. Optimization techniques were applied to determine the optimal design parameters of the corona ring. The results showed that considering the tower structure, conductor, hardware, and mutual phases significantly influenced the EFI distribution on the insulator creepage distance.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Engineering, Electrical & Electronic
Mojtaba Fekri, Javad Nikoukar, Gevork B. Gharehpetian
Summary: This paper proposes a cascading failure model based on transmission line thermal limit to extract and analyze hazardous high-probability scenarios of N-K (1<K<3) contingencies. The proposed fault evaluation method is employed for risk assessment of cascading failures and identification of their initial events. The proposed approach considers vulnerability criteria and operation constraints. The results of application to the standard IEEE 39-bus test system verify the efficiency and accuracy of the proposed approach.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Automation & Control Systems
Rohollah Abdollahi, Gevork B. Gharehpetian, Amjad Anvari-Moghaddam, Frede Blaabjerg
Summary: This article proposes a new simple pulse multiplication circuit (SPMC) with low current stress to upgrade a normal 20-pulse autotransformer rectifier (20PAR) to a 40PAR. The SPMC includes two tapped interphase reactors and two additional diodes with lower conduction losses. Compared to conventional pulse multiplication circuits, the proposed SPMC does not require a zero-sequence blocking transformer, making it simpler to implement. Simulation and experimental results show that the input current's total harmonic distortion using 40PAR is less than 3%, meeting the DO-160G requirements for aviation applications.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Green & Sustainable Science & Technology
Effat Ayoubi, Mohammad Reza Miveh, Ali Asghar Ghadimi, Sajad Bagheri, Masoud Mehrabi Koushki
Summary: This paper presents an enhanced sliding mode control method for minimizing neutral to the ground voltage (NGV) and total harmonic distortion (THD), while compensating for unbalanced load voltage conditions in a three-phase four-leg inverter. Simulation results using MATLAB/Simulink confirm the effectiveness of the proposed method.
IET RENEWABLE POWER GENERATION
(2023)
Article
Construction & Building Technology
Monir Kamali, Bahador Fani, Ghazanfar Shahgholian, Gevork B. Gharehpetian, Masoud Shafiee
Summary: In this study, an improved model of optimal power sharing, energy management, and THD control in AC microgrids is proposed. The model considers the random behavior of electric vehicles and aims to control voltage and frequency parameters. The primary controller focuses on optimal power sharing, impedance mismatch reduction, and THD reduction, while the secondary controller uses the PSO algorithm to minimize power distribution error and optimize virtual impedance parameters. The proposed model is compared with conventional and other meta-heuristic methods, and its stability is verified using various analysis techniques.
SUSTAINABLE CITIES AND SOCIETY
(2023)
Article
Computer Science, Information Systems
Arash Imanlou, Ebrahim Seifi Najmi, Reza Behkam, Morteza Nazari-Heris, Gevork B. Gharehpetian
Summary: This paper proposes a new high step-up DC-DC topology based on the active switched-inductor technique, which utilizes a coupled inductor for performance enhancement. The presented topology achieves better voltage gain and efficiency, reduces power loss by using MOSFETs with a low voltage rating, enhances voltage gain by reducing the turn ratio of the coupled inductor, achieves zero DC bias and solves the core saturation problem. Experimental results verify the validity of the study and the performance of the proposed topology.
Article
Computer Science, Information Systems
Alireza Asadi, Mohammad Saleh Karimzadeh, Xiaodong Liang, Mohammad Saeed Mahdavi, Gevork B. Gharehpetian
Summary: This paper presents a single-inductor multi-input single-output (SI-MISO) DC-DC boost converter for solar photovoltaic (PV) systems in DC or AC grids. The converter utilizes a new switching algorithm to independently control the output voltage and power absorbed from each source, resulting in a simple and unique controller. Additionally, a multivariable control system and a proportional-integral-derivative (PID) cascade control scheme are employed to achieve N number of single-input single-output (SISO) systems without switch delays. Experimental results confirm the accuracy and efficiency of the proposed control scheme using a 100-W prototype converter.
Article
Energy & Fuels
M. Akhlaghi, Z. Moravej, A. Bagheri
Summary: This paper investigates the incorporation of dynamic line and transformer ratings (DLR and DTR) into the optimal power flow problem in wind-energy-integrated power systems considering uncertainties. Uncertainty scenarios are generated using the Monte-Carlo method, and a convexification approach is applied to formulate the optimization problem as a mixed-integer quadratically-constrained programming (MIQCP). Experimental results demonstrate the efficiency of the proposed approach in reducing operating costs, minimizing load shedding cost, and maximizing the scheduling of wind power units as sustainable and clean energy resources.
SUSTAINABLE ENERGY GRIDS & NETWORKS
(2023)
Article
Engineering, Electrical & Electronic
Z. Moravej, A. Ebrahimi, M. Pazoki, M. Barati
Summary: This paper presents a new differential protection scheme for power transformers based on Intrinsic Time-Scale Decomposition (ITD) and Ensemble of Bagged Tree (EBT) as a classifier. The proposed scheme decomposes the input nonstationary signal using ITD and classifies different events using statistical time-domain features extracted from ITD output. The scheme has been tested under various operating conditions and has shown accuracy and robustness.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2023)
