@inproceedings{RahimpourBigdeli, author = {Rahimpour, Ebrahim and Bigdeli, Mehdi}, title = {Simplified transient model of transformer based on geometrical dimensions used in power network analysis and fault detection studies}, series = {IEEE SEcond International Conference on Power Engineering, Energy and Electrical Drives, Lisbon, Portugal, 18-20 March 2009}, booktitle = {IEEE SEcond International Conference on Power Engineering, Energy and Electrical Drives, Lisbon, Portugal, 18-20 March 2009}, doi = {10.1109/POWERENG.2009.4915148}, pages = {375 -- 380}, language = {en} } @inproceedings{RahimpourGorzinKaiumarzy, author = {Rahimpour, Ebrahim and Gorzin, Daniel and Kaiumarzy, Hadi}, title = {A new method for comparing the transfer function of transformers in order to detect the location of winding faults}, series = {13th Iranian Conference on Electrical Engineering, Zanjan, Iran, May 2005 (in Persian)}, volume = {4}, booktitle = {13th Iranian Conference on Electrical Engineering, Zanjan, Iran, May 2005 (in Persian)}, pages = {368 -- 373}, language = {en} } @inproceedings{FathiRahimpourZaree, author = {Fathi, Mehdi and Rahimpour, Ebrahim and Zaree, Kazem}, title = {Modeling of Magnetic Saturation of the Three Phase Induction Motor using the SIMULINK Software Package of MATLAB}, series = {6th Power System Conference, Tehran, Iran, October 2004 (in Persian)}, booktitle = {6th Power System Conference, Tehran, Iran, October 2004 (in Persian)}, language = {en} } @inproceedings{RahimpourLesaniMohsenietal., author = {Rahimpour, Ebrahim and Lesani, H. and Mohseni, Hossein and Christian, Jochen}, title = {Simulation and Analysis of the Transfer Function to Diagnose Mechanical faults in Transformer Windings}, series = {10th Iranian Conference on Electrical Engineering, Tabriz, Iran, May 2002}, volume = {4}, booktitle = {10th Iranian Conference on Electrical Engineering, Tabriz, Iran, May 2002}, pages = {654 -- 659}, language = {en} } @inproceedings{RahimpourChristianFeseretal., author = {Rahimpour, Ebrahim and Christian, Jochen and Feser, K. and Lesani, H.}, title = {Mathematical Model for Transformer Winding to Diagnose radial Deformation}, series = {16th International Power System Conference, Tehran, Iran, November 2001}, booktitle = {16th International Power System Conference, Tehran, Iran, November 2001}, language = {en} } @inproceedings{RahimpourChristianFeseretal., author = {Rahimpour, Ebrahim and Christian, Jochen and Feser, K. and Mohseni, Hossein}, title = {Ability of a Detailed Transformer Model to Diagnose Radial Deformation of Windings}, series = {International Conference on Advances in Processing, Testing and Application of Dielectric Materials, Wroclaw, Poland, 17-19 September, 2001}, booktitle = {International Conference on Advances in Processing, Testing and Application of Dielectric Materials, Wroclaw, Poland, 17-19 September, 2001}, language = {en} } @inproceedings{RahimpourChristianFeseretal., author = {Rahimpour, Ebrahim and Christian, Jochen and Feser, K. and Mohseni, Hossein}, title = {Calculation of the Transfer Function to Diagnose Axial Displacement and Radial Deformation of Transformer Windings}, series = {12th International Symposium on High Voltage Engineering, Bangalore, India, 20-24 August 2001}, volume = {5}, booktitle = {12th International Symposium on High Voltage Engineering, Bangalore, India, 20-24 August 2001}, number = {7-41}, pages = {1199-1202}, language = {en} } @inproceedings{RahimpourChristianFeseretal., author = {Rahimpour, Ebrahim and Christian, Jochen and Feser, K. and Mohseni, Hossein}, title = {Modeling of transformer windings for the calculation of the transfer function for the monitoring of transformers}, series = {15th International Power System Conference, Tehran, Iran, November 2000}, booktitle = {15th International Power System Conference, Tehran, Iran, November 2000}, language = {en} } @book{Rahimpour, author = {Rahimpour, Ebrahim}, title = {Hochfrequente Modellierung von Transformatoren zur Berechnung der {\"U}bertragungsfunktione}, publisher = {Shaker}, address = {Aachen, Germany}, isbn = {3826592271}, language = {de} } @article{GhorbalMirzaeiRahimpour, author = {Ghorbal, Mohammed Bilal and Mirzaei, Hassan Reza and Rahimpour, Ebrahim}, title = {Precise Modeling of Chopped Lightning Impulse Test of Power Transformers}, series = {Electric Power Systems Research}, volume = {230}, journal = {Electric Power Systems Research}, number = {110207}, publisher = {Elsevier}, doi = {10.1016/j.epsr.2024.110207}, abstract = {Performing insulation tests on power transformers is one of the most essential topics in high-voltage laboratories. According to international standards like IEC 60,076, full and chopped wave Lightning Impulse (LI) voltages must be applied to high voltage transformers. Since the wave shape parameters of the applied impulses must comply with the constraints that are specified in these standards, the setting of the impulse generator and test circuit must be modified correctly by test engineers. An accurate computerized simulation method is very desirable to help them accomplish this duty quickly and enhance the outcome results. Therefore, this paper proposes a method that is capable of simulating both Full Wave (FW) and Chopped Wave (CW) impulses in the time domain accurately. In this method, the frequency response of the transformer is measured and then the Vector Fitting (VF) technique is used to obtain its admittance model. Additionally, the transformer's impulse test circuit elements are precisely modelled. Afterwards, by solving the equations of the equivalent circuit in the state-space system, the time domain signals of all state variables are calculated. Finally, the output impulse voltages are computed. Several practical tests are accomplished on two power transformers to ensure the correctness of the proposed method.}, language = {en} } @inproceedings{FilipovićGrčićFrolovJurisicetal., author = {Filipović-Grčić, Bozidar and Frolov, Mikhail and Jurisic, Bruno and Manthe, Thomas and Matveev, Daniil and Rahimpour, Ebrahim}, title = {Consideration of Non-Standard Overvoltages Compared with Standard Overvoltages in Power Transformers}, series = {6th International Colloquium Transformer Research and Asset Management, Split, Croatia}, booktitle = {6th International Colloquium Transformer Research and Asset Management, Split, Croatia}, abstract = {Overvoltages that exist in the power system differ from the standard overvoltages (OVs) waveshape, that are used to test power equipment. In the paper typical OV waveshapes that occurs in the power system are analyzed, using the methods available in the literature: frequency domain severity factor (FDSF), time domain severity factor (TDSF) and the method from IEC 60071-2: 2018, Annex I. General remarks about applicability of these methods are given in the paper. It can be concluded that without the knowledge of transformer design and dielectric strength of an insulation system elements, the reliable estimation of non-standard overvoltages severity cannot be made. The results of the paper are in line with the conclusion of CIGRE WG A2.63: Transformer Impulse Testing.}, language = {en} } @inproceedings{RahimpourGhorbalMirzaei, author = {Rahimpour, Ebrahim and Ghorbal, Mohammed Bilal and Mirzaei, Hassan Reza}, title = {Evaluating the Influence of External Compensators on Chopped Impulse Waves in Power Transformer Testing}, series = {2024 IEEE International Conference on High Voltage Engineering and Applications, Berlin, Germany}, booktitle = {2024 IEEE International Conference on High Voltage Engineering and Applications, Berlin, Germany}, publisher = {IEEE}, isbn = {979-8-3503-7498-8}, doi = {10.1109/ICHVE61955.2024.10676122}, pages = {969 -- 972}, abstract = {Applying lightning impulse tests on high-voltage transformers plays a crucial role in evaluating their insulation system. The performance of the dielectric system in newly produced power transformers must satisfy the requirements of both full and chopped wave tests. To conduct these tests, standard full and chopped impulses are generated using the well-known Marx generator. The wave shape parameters of these impulses must fulfil the requirements that are specified in international standards such as IEC 60076. The excessive voltage collapse rate as well as the high amplitude of the first peak of the resulting overswing following the chopping time, highly stress the dielectric system of the power transformers. To resolve these issues, external elements may be added to the chopping circuit. These additional elements are essential in stabilizing the waveform by preventing excessive voltage collapse rate and controlling the peak of the first swing after chopping. Furthermore, some transformers with high power ratings may possess windings with very low inductance or high capacitance, which can undesirably impact the shape and parameters of the resulting full wave. To address these critical situations and bring the full wave parameters within the allowed limits, engineers in high-voltage laboratories employ some compensators like the Glaninger circuit in impulse circuits. It is important to study the effects of such compensators on chopped impulse parameters. This paper aims to investigate the impact of the mentioned external elements and compensators on the parameters of the chopped wave impulses. Specifically, the study focuses on assessing the influence of these compensators on voltage collapse and the peak amplitude of the first swing after chopping. By analyzing and understanding these effects, researchers and engineers can gain valuable insights into the performance and optimization of lightning impulse tests on power transformers, ultimately contributing to the advancement of high-voltage laboratory practices.}, language = {en} } @inproceedings{GhorbalMirzaeiRahimpouretal., author = {Ghorbal, Mohammed Bilal and Mirzaei, Hassan Reza and Rahimpour, Ebrahim and Rabih, S.}, title = {Analyzing the Possibility of Improving Waveform Shape in Lightning Impulse Testing of Distribution Transformers}, series = {28th Electrical Power Distribution Conference, Zanjan, Iran}, booktitle = {28th Electrical Power Distribution Conference, Zanjan, Iran}, pages = {1 -- 5}, language = {en} } @inproceedings{RahimpourAlAbadiGamil, author = {Rahimpour, Ebrahim and Al-Abadi, A. and Gamil, A.}, title = {Dynamisches Feuchtigkeitsgleichgewicht in fl{\"u}ssigkeitsgef{\"u}llten Transformatoren}, series = {17th Transformer-Life-Management Konferenz, Zeulenroda, Germany, 16-17 September 2024}, booktitle = {17th Transformer-Life-Management Konferenz, Zeulenroda, Germany, 16-17 September 2024}, language = {de} } @inproceedings{Rahimpour, author = {Rahimpour, Ebrahim}, title = {Herausforderungen der Blitzstoßspannungspr{\"u}fung an Leistungstransformatoren - {\"U}berblick {\"u}ber die CIGRE Arbeitsgruppe A2.63}, series = {16th Transformer-Life-Management Konferenz}, booktitle = {16th Transformer-Life-Management Konferenz}, language = {de} } @article{GustavsenRahimpour, author = {Gustavsen, B. and Rahimpour, Ebrahim}, title = {High-Frequency Transformer and Reactor Models for Network Studies, Part E: Measurements and transformer design details}, series = {Conseil International des Grands R{\´e}seaux {\´E}lectriques (CIGRE) TB 904}, journal = {Conseil International des Grands R{\´e}seaux {\´E}lectriques (CIGRE) TB 904}, isbn = {978-2-8587-3609-6}, pages = {1 -- 140}, language = {en} } @article{GustavsenRahimpour, author = {Gustavsen, B. and Rahimpour, Ebrahim}, title = {High-Frequency Transformer and Reactor Models for Network Studies, Part D: Model interfacing and specifications}, series = {Conseil International des Grands R{\´e}seaux {\´E}lectriques (CIGRE) TB 903}, journal = {Conseil International des Grands R{\´e}seaux {\´E}lectriques (CIGRE) TB 903}, isbn = {978-2-8587-3608-9}, pages = {1 -- 43}, language = {en} } @article{GustavsenRahimpour, author = {Gustavsen, B. and Rahimpour, Ebrahim}, title = {High-Frequency Transformer and Reactor Models for Network Studies, Part B: Black-Box Models}, series = {Conseil International des Grands R{\´e}seaux {\´E}lectriques (CIGRE) TB 901}, journal = {Conseil International des Grands R{\´e}seaux {\´E}lectriques (CIGRE) TB 901}, isbn = {978-2-8587-3606-5}, pages = {1 -- 88}, language = {en} } @article{GustavsenRahimpour, author = {Gustavsen, B. and Rahimpour, Ebrahim}, title = {High-Frequency Transformer and Reactor Models for Network Studies, Part A: White-Box Models}, series = {Conseil International des Grands R{\´e}seaux {\´E}lectriques (CIGRE) TB 900}, journal = {Conseil International des Grands R{\´e}seaux {\´E}lectriques (CIGRE) TB 900}, isbn = {978-2-8587-3605-8}, pages = {1 -- 203}, language = {en} } @article{GustavsenRahimpour, author = {Gustavsen, B. and Rahimpour, Ebrahim}, title = {High-Frequency Transformer and Reactor Models for Network Studies, Part C: Grey Box Models}, series = {Conseil International des Grands R{\´e}seaux {\´E}lectriques (CIGRE) TB 902}, journal = {Conseil International des Grands R{\´e}seaux {\´E}lectriques (CIGRE) TB 902}, isbn = {978-2-8587-3607-2}, pages = {1 -- 102}, language = {en} } @article{YuekselenRahimpour, author = {Y{\"u}kselen, Emir and Rahimpour, Ebrahim}, title = {An improvement in the design process of sustainable peak power rating transformer for solar utility}, series = {International Journal of Electrical Power \& Energy Systems}, volume = {170}, journal = {International Journal of Electrical Power \& Energy Systems}, publisher = {Elsevier BV}, issn = {0142-0615}, doi = {https://doi.org/10.1016/j.ijepes.2025.110928}, pages = {1 -- 13}, abstract = {The transformer industry faces critical challenges, such as maintaining reliable production while meeting rising sustainability requirements. This paper introduces a significant advancement in the design and optimization of a transformer dedicated to a photovoltaic power plant, which exhibits a unique loading cycle distinct from standard power and distribution transformers. The main aim is to minimize the carbon footprint by enhancing the design process to improve operational performance, efficiency, and functional reliability. Such upgrades are essential for transitioning to a zero-emission electricity system and developing green energy projects. In this paper, a transformer has been studied using a combination of electrical design and 3D finite element method simulation to evaluate various design parameters. An optimization study has been conducted using an innovative multi-objective genetic algorithm utilizing a cost function that factors in size and material costs to identify the most efficient and cost-effective design solutions. The proposed design method was then validated through thermal model simulations and experimental tests based on the photovoltaic load cycle. A comparison of critical thermal parameters directly affecting the transformer's lifetime and reliability was also drawn. The results were consistent with the expected outcomes, confirming the effectiveness and reliability of the proposed design methodology.}, language = {en} } @inproceedings{YuekselenRahimpour, author = {Y{\"u}kselen, Emir and Rahimpour, Ebrahim}, title = {An Optimization Approach for Sustainable Transformer Design in Photovoltaic Power Plants", 4th IEEE International Conference on Power Electronics Smart Grid and Renewable Energy}, series = {4th IEEE International Conference on Power Electronics Smart Grid and Renewable Energy}, booktitle = {4th IEEE International Conference on Power Electronics Smart Grid and Renewable Energy}, language = {en} } @inproceedings{MeuserRahimpour, author = {Meuser, Martin and Rahimpour, Ebrahim}, title = {Analyzing of Non-Standard Overvoltages in Different Types of Power Transformer Windings Using Frequency Domain and Time Domain Severity Factors}, series = {CIGRE SC A2 \& D1 Joint Colloquium}, booktitle = {CIGRE SC A2 \& D1 Joint Colloquium}, language = {en} } @inproceedings{RahimpourPortilloDragostinov, author = {Rahimpour, Ebrahim and Portillo, A. and Dragostinov, S.}, title = {Testing Challenges in Impulse Testing of Transformers}, series = {CIGRE SC A2 \& D1 Joint Colloquium}, booktitle = {CIGRE SC A2 \& D1 Joint Colloquium}, language = {en} } @inproceedings{AbouhosseiniDarziRahimpourMirzaieetal., author = {Abouhosseini-Darzi, Mohammad and Rahimpour, Ebrahim and Mirzaie, Mohammad and Shayegani Akmal, Amir Abbas}, title = {Investigating the Effects of Moisture Distribution on the Electric Field and Leakage Current of Power Transformer Bushings}, series = {IEEE Electrical Insulation Conference (EIC)}, booktitle = {IEEE Electrical Insulation Conference (EIC)}, publisher = {IEEE}, isbn = {979-8-3315-2608-5}, issn = {2993-3684}, doi = {10.1109/EIC63069.2025.11123376}, abstract = {Bushings are one of the most important and essential equipment of power transformers. Statistics show that one of the main causes of transformer failures is due to bushing problems. One of the main reasons for bushing failures is the penetration of moisture into its internal insulation system. The moisture affects the dielectric properties and leads to an increase in its leakage current. These effects lead to changes in the electric field of the inner insulating layers of the bushings, so it is necessary to investigate these effects. In this paper, the changes of the electric field in the insulating layers of a sample bushing have been investigated with considering the different moisture distribution between the layers. This evaluation has been done during the moisture diffusion time, from the start of penetration to the time of uniformity of moisture in all layers. Also, the moisture effects on the bushing leakage current under above conditions have been studied. For this purpose, an OIP bushing is modeled in COMSOL Multiphysics software and the simulations are carried out based on Finite Element Method (FEM) and finally the obtained results are analyzed. The results show that the moisture distribution in the bushing can have an important effect on the internal electric fields. Also, according to the results, the moisture distribution inside the bushing does not have a great effect on the leakage current and this current is only affected by the volume of the moisture penetrated inside the bushing.}, language = {en} } @article{AbouhosseiniDarziMirzaieShayeganiAkmaletal., author = {Abouhosseini-Darzi, Mohammad and Mirzaie, Mohammad and Shayegani Akmal, Amir Abbas and Rahimpour, Ebrahim}, title = {Calculation and Analysis of the Electric Field of the OIP Bushings under Internal Humidity and Surface Polluted Conditions using FEM}, series = {Iranian Journal of Electrical and Electronic Engineering}, volume = {21}, journal = {Iranian Journal of Electrical and Electronic Engineering}, number = {3}, doi = {10.22068/IJEEE.21.3.3360}, pages = {1 -- 11}, abstract = {Bushings are one of the most important components of electrical equipment such as power transformers, reactors, capacitors. Most of the installed bushings have Oil-Immersed Paper (OIP) insulation structure. Bushing failure is caused by various reasons such as poor manufacturing process, overloading and also poor installation process, but moisture ingress is one of the main reasons of OIP bushing defect during its operation. In this paper, the electric field distribution of OIP bushings in multiple situations are simulated and effects of moisture distribution are analyzed. The simulations are stablished in polluted and clean surfaces of the studied bushing and done by COMSOL Multiphysics Software. The results show that non-uniform moisture distribution has a significant effect on electric fields of OIP insulation. This effect strongly increases with increasing the pollution on the external insulator of the bushing. © 2025, Iran University of Science and Technology. All rights reserved.}, language = {en} } @inproceedings{AlAbadiRahimpourGamil, author = {Al-Abadi, A. and Rahimpour, Ebrahim and Gamil, Ahmed}, title = {Dynamisches thermisches Verhalten von mit Ester-Fl{\"u}ssigkeit gef{\"u}llten Transformatoren f{\"u}r Offshore-Windkraftanwendungen in kalten Klimazonen}, series = {18th Transformer-Life-Management Konferenz}, booktitle = {18th Transformer-Life-Management Konferenz}, language = {de} } @inproceedings{RahimpourGhorbalMirzaei, author = {Rahimpour, Ebrahim and Ghorbal, Mohammed Bilal and Mirzaei, Hassan Reza}, title = {Application of the Nonlinear Kernel Principal Component Analysis in Detecting Disk-to-Disk Faults along a Transformer Winding}, series = {3rd International Conference - Tesla Innovation Days}, booktitle = {3rd International Conference - Tesla Innovation Days}, language = {en} } @inproceedings{GhorbalMirzaeiRahimpour, author = {Ghorbal, Mohammed Bilal and Mirzaei, Hassan Reza and Rahimpour, Ebrahim}, title = {Detection of Disk Space Variation in Power Transformers using Nonlinear Dimensionality Reduction Algorithm}, series = {24th International Symposium on High Voltage Engineering}, booktitle = {24th International Symposium on High Voltage Engineering}, language = {en} } @inproceedings{MeuserRahimpourEslamian, author = {Meuser, Martin and Rahimpour, Ebrahim and Eslamian, Morteza}, title = {An Inductance Matrix Expansion Method for Transient Analysis of Power Transformer using Single Turn Model}, series = {24th International Symposium on High Voltage Engineering}, booktitle = {24th International Symposium on High Voltage Engineering}, language = {en} } @inproceedings{MeuserRahimpourEslamian, author = {Meuser, Martin and Rahimpour, Ebrahim and Eslamian, Morteza}, title = {Induktivit{\"a}tsmatrixerweiterung f{\"u}r die Transientenanalyse in Leistungstransformatoren}, series = {18th Transformer-Life-Management Konferenz}, booktitle = {18th Transformer-Life-Management Konferenz}, language = {de} } @article{GustavsenRahimpour, author = {Gustavsen, B. and Rahimpour, Ebrahim}, title = {High-Frequency Transformer and Reactor Models for Network Studies}, series = {Electra}, journal = {Electra}, number = {328}, pages = {1 -- 13}, language = {en} }