TY - CHAP A1 - Filipović-Grčić, Bozidar A1 - Frolov, Mikhail A1 - Jurisic, Bruno A1 - Manthe, Thomas A1 - Matveev, Daniil A1 - Rahimpour, Ebrahim T1 - Consideration of Non-Standard Overvoltages Compared with Standard Overvoltages in Power Transformers T2 - 6th International Colloquium Transformer Research and Asset Management, Split, Croatia N2 - 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. Y1 - 2023 UR - https://www.researchgate.net/publication/376812552_Consideration_of_Non-Standard_Overvoltages_Compared_with_Standard_Overvoltages_in_Power_Transformers ER - TY - CHAP A1 - Rahimpour, Ebrahim A1 - Ghorbal, Mohammed Bilal A1 - Mirzaei, Hassan Reza T1 - Evaluating the Influence of External Compensators on Chopped Impulse Waves in Power Transformer Testing T2 - 2024 IEEE International Conference on High Voltage Engineering and Applications, Berlin, Germany N2 - 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. KW - Marx impulse generator KW - Lightning impulse test KW - chopped wave KW - Overswing KW - Compensator Y1 - 2024 SN - 979-8-3503-7498-8 U6 - https://doi.org/10.1109/ICHVE61955.2024.10676122 SP - 969 EP - 972 PB - IEEE ER - TY - CHAP A1 - Ghorbal, Mohammed Bilal A1 - Mirzaei, Hassan Reza A1 - Rahimpour, Ebrahim A1 - Rabih, S. T1 - Analyzing the Possibility of Improving Waveform Shape in Lightning Impulse Testing of Distribution Transformers T2 - 28th Electrical Power Distribution Conference, Zanjan, Iran Y1 - 2024 SP - 1 EP - 5 ER - TY - CHAP A1 - Rahimpour, Ebrahim A1 - Al-Abadi, A. A1 - Gamil, A. T1 - Dynamisches Feuchtigkeitsgleichgewicht in flüssigkeitsgefüllten Transformatoren T2 - 17th Transformer-Life-Management Konferenz, Zeulenroda, Germany, 16-17 September 2024 Y1 - 2024 ER - TY - CHAP A1 - Rahimpour, Ebrahim T1 - Herausforderungen der Blitzstoßspannungsprüfung an Leistungstransformatoren - Überblick über die CIGRE Arbeitsgruppe A2.63 T2 - 16th Transformer-Life-Management Konferenz Y1 - 2023 ER - TY - JOUR A1 - Gustavsen, B. A1 - Rahimpour, Ebrahim T1 - High-Frequency Transformer and Reactor Models for Network Studies, Part E: Measurements and transformer design details JF - Conseil International des Grands Réseaux Électriques (CIGRE) TB 904 Y1 - 2023 SN - 978-2-8587-3609-6 SP - 1 EP - 140 ER - TY - JOUR A1 - Gustavsen, B. A1 - Rahimpour, Ebrahim T1 - High-Frequency Transformer and Reactor Models for Network Studies, Part D: Model interfacing and specifications JF - Conseil International des Grands Réseaux Électriques (CIGRE) TB 903 Y1 - 2023 SN - 978-2-8587-3608-9 SP - 1 EP - 43 ER - TY - JOUR A1 - Gustavsen, B. A1 - Rahimpour, Ebrahim T1 - High-Frequency Transformer and Reactor Models for Network Studies, Part B: Black-Box Models JF - Conseil International des Grands Réseaux Électriques (CIGRE) TB 901 Y1 - 2023 SN - 978-2-8587-3606-5 SP - 1 EP - 88 ER - TY - JOUR A1 - Gustavsen, B. A1 - Rahimpour, Ebrahim T1 - High-Frequency Transformer and Reactor Models for Network Studies, Part A: White-Box Models JF - Conseil International des Grands Réseaux Électriques (CIGRE) TB 900 Y1 - 2023 SN - 978-2-8587-3605-8 SP - 1 EP - 203 ER - TY - JOUR A1 - Gustavsen, B. A1 - Rahimpour, Ebrahim T1 - High-Frequency Transformer and Reactor Models for Network Studies, Part C: Grey Box Models JF - Conseil International des Grands Réseaux Électriques (CIGRE) TB 902 Y1 - 2023 SN - 978-2-8587-3607-2 SP - 1 EP - 102 ER -