Saeed Moharrami Shahbekandi
97421 Schweinfurt
Forschungsschwerpunkte
Transient Modelling of Power Transformer
For large high-voltage (HV), Extra High Voltage (EHV), and Ultra High Voltage (UHV) power transformers, the intense stresses generated by transient overvoltages (TO) require the use of accurate models for insulation design optimisation and detailed diagnostic studies.
The primary goal of transformer modelling is to reproduce the transformer's transient behavior, thereby allowing designers and engineers to predetermine internal electrical stresses and effectively mitigate potential hazards. Accurate modelling also allows designers to identify potential resonance locations and analyse the winding's amplitude-frequency response characteristics.
The evolution of transformer winding modeling demonstrates a clear technical trajectory aimed at creating models that are both highly accurate (necessary for phenomena like very fast transient overvoltages (VFTO) and partial discharge that contain energy in the MHz range) and computationally efficient (required for feasibility in large scale network simulations).
The Multi-Transmission-Line (MTL) approach, including its geometry-conscious successors, seems the most accurate method for calculating impedance and admittance matrices over a wide frequency band. However, their inherent complexity makes them computationally excessive for many practical transient studies.
The complexity of modeling mandates that computational efficiency is continuously addressed. Detailed MTL models, while accurate, require very large matrices, necessitating model reduction techniques to minimize computational time.
On the other hand, Single Turn model based on lumped parameter models (LPM-STM) modeling is expected to provide satisfactory accuracy for VFTO.
A gap in the literature that needs to be addressed is the lack of complete attention given to LPM-STM, as most of the literature has focused on Disk Pair model based on lumped parameter models (LPM-DPM) and MTL.
Publikationen
Conference Papers
1) S. Moharrami, H. Asadpour, H. Heidary and M. Ansari, " ANN-Driven Energy Loss Quantification in Modern Distribution Grids: An Intelligent Framework for Grid Efficiency Evaluation ," 2025 29th International Electrical Power Distribution Conference (EPDC), Tehran, Iran, 2025, pp. 1-6, doi: 10.1109/EPDC67173.2025.11278290.
Available online: ieeexplore.ieee.org/document/11278290
2) S. Moharrami, H. Asadpour, M. Samadi and M. Mohammadjafari, " System-Wide Temporal Characterization of Technical Loss Time-Series Patterns and Energy Loss Factor Behavior: A High-Resolution Empirical Study of Macro-Scale Power Distribution Networks ," 2025 29th International Electrical Power Distribution Conference (EPDC), Tehran, Iran, 2025, pp. 1-4, doi: 10.1109/EPDC67173.2025.11278299.
Available online: ieeexplore.ieee.org/document/11278299
3) S. Moharrami, M. Ansari and H. Heydari, " Enhancing Demand Side Management through Clustering Feeders with Industrial Consumption ," 2024 28th International Electrical Power Distribution Conference (EPDC), Zanjan, Iran, 2024, pp. 1-5, doi: 10.1109/EPDC62178.2024.10571697.
Available online: ieeexplore.ieee.org/document/10571697
4) S. Moharrami and H. Mokhtari, " Experimental Validation of Frequency Response of a CVT for EHV Harmonic Measurements ," 2022 International Conference on Protection and Automation of Power Systems (IPAPS), Zahedan, Iran, 2022, pp. 1-6, doi: 10.1109/IPAPS55380.2022.9763197.
Available online: ieeexplore.ieee.org/document/9763197