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Mirzadarani, R. (author), Ghaffarian Niasar, M. (author), Li, Z. (author), Qin, Z. (author), Vaessen, P.T.M. (author), Bauer, P. (author), Van Lieshout, Lou (author)Green hydrogen production uses renewable energies to energise the electrolysers for hydrogen production. The present paper compares possible solutions and configurations of a medium-frequency transformer (MFT) as part of a solid-state transformer (SST) in green hydrogen production applications. The single-phase and three-phase MFTs are compared...conference paper 2023
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Heidary, Amir (author), Popov, M. (author), Moghim, Ali (author), Ghaffarian Niasar, M. (author), Lekić, A. (author)The significance of battery energy storage systems (BESSs) technology has been growing rapidly, mostly due to the need for microgrid applications and the integration of renewables. Relevant to the importance of utilization of BESS in microgrids, the protection of the BESS during microgrid faults has become a concern too. The short circuit in...journal article 2023
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Chen, Y. (author), Castro Heredia, L.C. (author), Smit, J.J. (author), Ghaffarian Niasar, M. (author), Ross, Robert (author)Partial discharge (PD) detection is a standardized technique to qualify the insulation condition in power equipment. The main purpose of the article is to evaluate the performance of an extra high-sensitivity adapted giant magneto-resistive (xMR) sensor for non-contacting PD detection. First, compensation and signal conditioning circuits of...journal article 2023
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Mathew, P. (author), Ghaffarian Niasar, M. (author)With the increasing penetration of power electronic interfaces in the power grid, insulation materials will begin to experience stresses at higher frequencies than the conventional 50 Hz AC. This article studies the lifetime curves of oil-impregnated paper (OIP) under pulsed stresses and compares them at 10 kHz and 50 kHz. A pulse modulator is...conference paper 2022
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Ganeshpure, D.A. (author), Soundararajan, Ajeeth Phrassanna (author), Soeiro, Thiago B. (author), Ghaffarian Niasar, M. (author), Vaessen, P.T.M. (author), Bauer, P. (author)This article compares the pulse current capability of various Semiconductor (SM) device technologies for Modular Multilevel Converter (MMC)-based High Voltage (HV) Arbitrary Waveform Generator (AWG) for dielectric testing of grid assets to find the most suitable SM device technology which can perform well in generating lightning impulse that...conference paper 2022
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Luo, T. (author), Ghaffarian Niasar, M. (author), Vaessen, P.T.M. (author)Winding loss calculation is essential for inductor and transformer design. In this article, a revised 1-D Ferreira's formula is proposed, which considers the interaction between conductors. Then, a 2-D loss calculation approach is proposed based on the analytical solution of round conductors under a uniform external field. An equivalent...journal article 2022
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Zang, Y. (author), Qian, Yong (author), Zhou, Xiaoli (author), Ghaffarian Niasar, M. (author), Sheng, Gehao (author), Jiang, Xiuchen (author)Optical partial discharge (PD) detection is an efficient means of diagnosing the insulation status of power equipment. C4F7N/CO2 gas mixture is a very potential environmentally-friendly SF6 substitute gas, and its PD optical characteristics need to be studied to guide the PD diagnosis of novel C4F7N/CO2 equipment. Therefore, this article...journal article 2022
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Zang, Y. (author), Ghaffarian Niasar, M. (author), Ganeshpure, D.A. (author), Qian, Yong (author), Sheng, Gehao (author), Jiang, Xiuchen (author), Vaessen, P.T.M. (author)With the widespread application of power electronic switching technology, power equipment is facing new electrical stresses brought about by multilevel staircase voltages during testing and operation. Therefore, the partial discharge (PD) behavior of five typical defects in power equipment under the staircase waveform needs to be investigated...journal article 2022
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Zang, Yiming (author), Ghaffarian Niasar, M. (author), Qian, Yong (author), Zhou, Xiaoli (author), Sheng, Gehao (author), Jiang, Xiuchen (author), Vaessen, P.T.M. (author)Realization of an electrical aircraft demands a low-weight electric distribution and propulsion system. The use of high voltage and power electronics operated at high switching frequencies is essential to achieve this objective. However, printed circuit boards (PCBs) in electrified aircraft are in a harsh working environment, which can make...journal article 2022
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Zhao, W. (author), Luo, T. (author), Ghaffarian Niasar, M. (author)In this study, the immediate time to breakdown for pure epoxy resin is measured by applying a ramp sinusoidal voltage signal at certain frequency (50Hz, 500Hz and 5000Hz) until breakdown occurs. The HV testing procedures, epoxy resin sample and experimental set-up preparation and Weibull analysis of obtained results are elaborated. The...conference paper 2021
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Luo, T. (author), Zhao, W. (author), Ghaffarian Niasar, M. (author)With widely use of power electronics in medium voltage level, there is increasing concern about behaviour of insulation material under arbitrary voltage stress. Solid-gas insulation is a general choice in medium voltage level. Therefore, it’s unavoidable to encounter surface discharge problem. In this paper, the surface discharge on epoxy-air...conference paper 2021
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Ganeshpure, D.A. (author), Castro Heredia, L.C. (author), Ghaffarian Niasar, M. (author), Vaessen, P.T.M. (author), Soeiro, Thiago B. (author), Bauer, P. (author)This paper presents a comparison in Partial Discharge (PD) behaviour when an air corona setup is subjected to different waveforms, namely an idealized 50 Hz sinusoidal and staircase-based sinusoidal waveforms near inception voltage and at a higher voltage. In this study, it has been observed that the PD repetition rate and the Phase-Resolved PD ...conference paper 2021
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Ganeshpure, D.A. (author), Soeiro, Thiago B. (author), Ghaffarian Niasar, M. (author), Vaessen, P.T.M. (author), Bauer, P. (author)This paper comprehensivelyinvestigates the design trade-offs of a Modular Multilevel Converter (MMC) operations as an Arbitrary Wave shapesGenerator (AWG) to perform High Voltage (HV) dielectric testing of different grid assets. HV AWG applications pose unique operatingconditions to the MMC, which influences the selection of the various...journal article 2021
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Ghaffarian Niasar, M. (author), Zhao, W. (author)In this work, breakdown strength and lifetime curve of oil-impregnated paper (OIP) are compared at 50Hz and 1500 Hz. For the ramp breakdown tests, sinusoidal voltage ramp of 1 kVp/s is used. The ramp breakdown experiments is conducted on OIP samples made of single and double sheets of OIP. Weibull plots and interpretation of the results are...conference paper 2021
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Hesam Mahmoudi Nezhad, N. (author), Ghaffarian Niasar, M. (author), Mohammadi Gheidari, A. (author), Kruit, P. (author), Hagen, C.W. (author)The design of an electrostatic electron optical system with five electrodes and two objective functions is optimized using multiobjective genetic algorithms (MOGAs) optimization. The two objective functions considered are minimum probe size of the primary electron beam in a fixed image plane and maximum secondary electron detection efficiency...journal article 2021
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Ganeshpure, D.A. (author), Soeiro, Thiago B. (author), Ghaffarian Niasar, M. (author), Vaessen, P.T.M. (author), Bauer, P. (author)This paper analyses different design trade-offs for a Modular Multilevel Converter (MMC)-based Arbitrary Wave shape Generator (AWG) used for High Voltage (HV) testing and certification of grid assets such as transformers, switchgear, and cables. Modulation techniques, number of submodules, output voltage levels, arm inductance, and series...conference paper 2021
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Yu, G. (author), Ghaffarian Niasar, M. (author), Ganeshpure, D.A. (author), Soeiro, Thiago B. (author), Bauer, P. (author)SiC MOSFETs have become more and more popular in recent years. Apart from its superior performance, attentions should be paid to its driving method. In this paper, an improved transformer driving circuit is proposed which can provide an almost constant negative turn-off voltage within a wide dutycycle range. Both simulation and experimental...conference paper 2021
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Ghaffarian Niasar, M. (author), Wang, Xiaolei (author), Kiiza, Respicius Clemence (author)When detecting the presence of partial discharge (PD) activity in the insulation system in high-voltage equipment, the excitation voltages at variable frequency have been widely used instead of power-frequency (50/60 Hz) sinusoidal voltage in order to reduce the charging power. This work reviews the relevant research on PD activity at very low...journal article 2021
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Iannarelli, A. (author), Ghaffarian Niasar, M. (author), Ross, Robert (author)Dielectric elastomer actuators (DEAs) are a class of electrostatic actuators that have promising applications in fields like sensors, soft-robotics, microfluidics, and energy harvesting. The crucial points in the working principle of DEA are the application of high electric field and the use of compliant electrodes. These electrodes are...journal article 2020
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Hesam Mahmoudi Nezhad, N. (author), Ghaffarian Niasar, M. (author), Hagen, C.W. (author), Kruit, P. (author)In electron optics, the design of electron lens systems is still a challenge. To optimize such systems, the objective function which should be calculated, depends on the electric potential distribution in the space created by the lenses. To obtain the electric potential, the existing methods are generally based on some mathematical techniques...conference paper 2020