Navid Fahimi

@iust.ac.ir

Assistant Professor of Electrical Engineering, Iran University of Science & Technology (IUST)
Iran University of Science and Technology

Navid Fahimi


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https://researchid.co/nfahimi

RESEARCH, TEACHING, or OTHER INTERESTS

Electrical and Electronic Engineering
13

Scopus Publications

157

Scholar Citations

8

Scholar h-index

7

Scholar i10-index

Scopus Publications

  • A Multi-Stage physics-informed neural network for optimal lightning protection design in solar power plants
    Hamid Reza Sezavar, Navid Fahimi, Hamid Karimi
    Electric Power Systems Research, 2026
  • Biologically inspired survival analysis framework for failure monitoring of composite insulators using leakage current
    Navid Fahimi, Hamid Reza Sezavar
    Results in Engineering, 2026
    • Multi-aspect feature engineering enables precise failure tracking. • A survival model using dynamic-weighted Cox-RSF provides accurate risk measurement. • Clinical interpretability allows reliable classification by risk scores. • Measurement correctness is validated using C-index and IBS benchmarks. Composite insulators are subject to degradation and failure due to harsh environmental stresses like pollution, moisture and discharge activities. Conventional condition-assessment techniques such as threshold-based leakage current (LC) analysis are unable to predict time-to-failure and present survival probability. A hybrid prognostic framework is proposed in this paper based on medical survival analysis that considers insulator failure as a time-to-event problem with purpose of uncertainty quantification. Electrical engineering diagnostics are integrated with bio-statistical survival models in this work for speed-precision compensation in real practices. LC waveforms from flashover tests under different pollution levels are analyzed to extract performance indexes including temporal quantities, frequency properties and nonlinear dynamics. These indexes are used to train two survival models: Cox proportional hazards model for pollution and LC entropy and random survival forest (RSF) for capturing nonlinear discharge paths with time-dependent weighting. Validation on test data from 5 insulators shows superiority of the presented approach to some similar methods in terms of measurement correctness as C-index, integrated brier score (IBS) and risk stratification. The presented monitoring framework can be used as a data-driven tool to reduce unplanned outages particularly in cases of poor-data environment and measurement uncertainties due to incomplete observations.
  • A novel hybrid mathematical deep learning technique for early warning of flashover in composite insulators
    Hamid Reza Sezavar, Saeed Hasanzadeh, Navid Fahimi
    Scientific Reports, 2025
    This paper presents a novel approach based on a hybrid mathematical deep-learning model for flashover prediction of the polluted composite insulators. The proposed prediction method has been designed according to critical pre-flashover conditions, including the dry-band arcing (DBA) and flashover (FO) stages. The feature achievement is developed based on weighted continuous wavelet transform (WCWT) analysis that can discharge counting as a performance index according to real sample test leakage current (LC) data. It is shown that the application of the presented WCWT is superior to that of the typical wavelet analysis. Then, flashover prediction is achieved using the combination of a novel graph attention network (GAT) based on extracted indexes of the discharge peak number and power fitted on a Gaussian function. The developed prediction model can be used as an early-warning tool to prevent outages due to insulator failures. Validation of the presented model for predicting dry-band arcing and flashover is investigated for several parameters, such as the geometry specification of the samples and pollution levels. In addition, a flowchart is represented for online monitoring applications based on the proposed approach.
  • Failure evaluation of outdoor polymeric insulators based on statistical condition-assessment methods
    Navid Fahimi, Mohammad Goudarzi, Amir Abbas Shayegani-Akmal
    Electric Power Systems Research, 2025
  • A techno-economic model for enhancing PV hosting capacity through capabilities of smart inverters and soft open points
    Rezvaneh Golnazari, Saeed Hasanzadeh, Ehsan Heydarian‐Forushani, Hamid Reza Sezavar, Navid Fahimi
    Iet Renewable Power Generation, 2024
    The hosting capacity of solar photovoltaics (PVs) in the distribution network can be impacted by the violation of power flow constraints such as power loss, voltage, and line loadings. In this paper, a planning structure based on optimal PV placement and optimal operation of the smart inverters and soft open point (SOP) is proposed in order to investigate the loss of power, voltage profiles, line loadings and total operation cost of the distribution system. The stochastic nature of the daily load and PV generation is considered in power flow optimization by the proposed method. Respective objective functions are optimized using a genetic algorithm (GA) according to probabilistic power flow. While the desired objective function is optimized, the optimality of the PV locations and contribution of smart inverters and SOP is ensured through GA optimization. The proposed model is investigated through numerical analyses on IEEE 33‐bus and IEEE 69‐bus distribution systems considering different cases of reactive power supports. Developed GA is able to deal with challenges of convergence that are imposed by complex nonlinear formulations. Obtained results prove the superiority of the developed program for the investigation of the PV hosting capacity in both technical and cost aspects.
  • Risk assessment of contaminated composite insulators in pre-flashover conditions
    H.R. Sezavar, N. Fahimi, S. Hasanzadeh, A.A. Shayegani Akmal
    Electric Power Systems Research, 2024
  • Flashover Prediction of Polymer Insulators Based on Dynamic Modeling of Pollution Layer Resistance Using ANN
    N. Fahimi, H. R. Sezavar, A. A. Shayegani-Akmal
    IEEE Transactions on Dielectrics and Electrical Insulation, 2023
    In this article, a novel dynamic approach is proposed to analyze pollution layer resistance of polymer insulators. One of the main challenges in dynamic modeling of pollution layer resistance is the effects of pollution layer conduction and pollution layer thickness on discharge length due to change in pollution layer thickness and wetting rate in real outdoor conditions. The represented approach investigates the effects of such parameters on variation of discharge length. Then, an artificial intelligence (AI) algorithm based on artificial neural network (ANN) is developed to predict flashover voltage (FOV) of polluted insulators according to the prediction of critical discharge length. Calculations are done based on experimental data of leakage current (LC) and voltage of insulators in different pollution conditions. Obtained results by the proposed approach show a close correlation with experimental results. In addition, various validation tests are performed to investigate the effects of hydrophobicity class (HC) of polymeric surface and pollution type on the quality of the represented analysis. Results of the validation also show a close correlation between calculations and real data.
  • A Dynamic Intelligent Approach Based on Gaussian Function for Prediction of the Flashover Voltage Conditions on Polluted Polymer Insulators
    Hamid Reza Sezavar, Navid Fahimi, Amir Abbas Shayegani
    IEEE Transactions on Power Delivery, 2022
    This research presents a dynamic modeling approach to predict flashover voltage (FOV) of polymer insulators. Pre-flashover conditions can be used to represent analytical formulations for different stages of dry band arcing activities on the surface of polluted insulator. In this study, experimental results of pollution flashover tests are used to develop a circuit model of pollution arcs based on Obenaus’ model. Estimation of circuit values is done by use of intelligent algorithm with no dependency on profile of insulators which is also more beneficial than typical analytical calculations. Then, separation and investigation of discharge and pollution voltage is done and proper classification is made. This classification is later used to predict pre-flashover conditions and pollution flashover. Gaussian model is used to make fitness of voltage of pollution layer and voltage of discharge on the surface of insulator. Gaussian representation of each stage in pollution flashover contains critical signals leading to complete discharge. Based on the obtained model, a flowchart is presented to predict dynamic stages of flashover. Comparison to various experimental data shows close correlations with the results of proposed model. An online monitoring system can be developed according to obtained results in order to prevent pollution flashover.
  • Dynamic modeling of flashover of polymer insulators under polluted conditions based on HGA-PSO algorithm
    Navid Fahimi, Hamid Reza Sezavar, Amir Abbas Shayegani Akmal
    Electric Power Systems Research, 2022
  • An Improved Dynamic Multi-Arcs Modeling Approach for Pollution Flashover of Silicone Rubber Insulator
    Hamid Reza Sezavar, Navid Fahimi, Amir Abbas Shayegani-Akmal
    IEEE Transactions on Dielectrics and Electrical Insulation, 2022
    This article presents a dynamic modeling approach to analyze pollution flashover of silicone rubber insulators. Pre-flashover conditions can be used to represent analytical formulations for different stages of dry band arcing activities on the surface of polluted insulator. In this article, effects of dust deposit as nonsoluble deposit density (NSDD) are investigated on the dynamic behavior of partial arcs on the surface of insulators by means of a proposed multi-arcs modeling approach. It is shown that analytical formulations of dynamic resistance of surface pollution can be used to analyze different modes of arcing as unstable and stable. Real data of leakage current (LC) and flashover voltage (FOV) of polluted insulator are used to make correlation with analytical multi-arcs formulations. The proposed analytical multi-arcs model is based on an artificial neural network (ANN) which is able to predict the LC and FOV of the insulator in real-time monitoring. In addition, effects of pollution resistance as variable surface conduction and thickness of pollution layer are investigated on LC and FOV of the insulators. It is shown that the proposed multi-arcs representation has a closer correlation with real testing data in comparison to previous single-arc and multi-arcs models.
  • Method to design saturated iron-core fault current limiters
    Mohamadreza Arab Baferani, Navid Fahimi, Amir Abbas Shayegani
    Iet Generation Transmission and Distribution, 2019
  • A novel arrangement for improving three phase saturated-core fault current limiter (SCFCL)
    Mohammadreza Arab Baferani, Mojtaba Rostaghi Chalaki, Navid Fahimi, Amir Abbas Shayegani, Kaveh Niayesh
    2018 IEEE Texas Power and Energy Conference Tpec 2018, 2018
  • Investigating the failures of defected silicon rubber insulators in salt-fog chamber
    Navid Fahimi, Mojtaba Rostaghi Chalaki, Mohammadreza Arab Baferani, Mohammad Reza Tajik, Amir Abbas Shayegani
    2018 IEEE Texas Power and Energy Conference Tpec 2018, 2018

RECENT SCHOLAR PUBLICATIONS

  • A Multi-Stage physics-informed neural network for optimal lightning protection design in solar power plants
    HR Sezavar, N Fahimi, H Karimi
    Electric Power Systems Research 256, 112879 , 2026
    2026.0
  • Biologically Inspired Survival Analysis Framework for Failure Monitoring of Composite Insulators Using Leakage Current
    N Fahimi, HR Sezavar
    Results in Engineering, 108742 , 2025
    2025.0
    Citations: 1
  • A novel hybrid mathematical deep learning technique for early warning of flashover in composite insulators
    HR Sezavar, S Hasanzadeh, N Fahimi
    Scientific Reports 15 (1), 33448 , 2025
    2025.0
    Citations: 3
  • Failure evaluation of outdoor polymeric insulators based on statistical condition-assessment methods
    N Fahimi, M Goudarzi, AA Shayegani-Akmal
    Electric Power Systems Research 238, 111134 , 2025
    2025.0
    Citations: 2
  • A techno‐economic model for enhancing PV hosting capacity through capabilities of smart inverters and soft open points
    R Golnazari, S Hasanzadeh, E Heydarian‐Forushani, HR Sezavar, ...
    IET Renewable Power Generation 18, 4233-4248 , 2024
    2024.0
    Citations: 3
  • Risk assessment of contaminated composite insulators in pre-flashover conditions
    HR Sezavar, N Fahimi, S Hasanzadeh, AAS Akmal
    Electric Power Systems Research 230, 110256 , 2024
    2024.0
    Citations: 20
  • Numerical Investigation of Effects of Plasma Actuator Placement on Aerodynamic Parameters of NACA 0012 Airfoil
    N Fahimi, H Masoudi-Rad, MA Vaziri, M Ghadak
    Fluid Mechanics & Aerodynamics 12 (1), 65-74 , 2024
    2024.0
  • Flashover prediction of polymer insulators based on dynamic modeling of pollution layer resistance using ANN
    N Fahimi, HR Sezavar, AA Shayegani-Akmal
    IEEE Transactions on Dielectrics and Electrical Insulation 30 (1), 122-130 , 2022
    2022.0
    Citations: 18
  • Dynamic modeling of flashover of polymer insulators under polluted conditions based on HGA-PSO algorithm
    N Fahimi, HR Sezavar, AAS Akmal
    Electric Power Systems Research 205, 107728 , 2022
    2022.0
    Citations: 19
  • An improved dynamic multi-arcs modeling approach for pollution flashover of silicone rubber insulator
    HR Sezavar, N Fahimi, AA Shayegani-Akmal
    IEEE Transactions on Dielectrics and Electrical Insulation 29 (1), 77-85 , 2022
    2022.0
    Citations: 19
  • A dynamic intelligent approach based on Gaussian function for prediction of the flashover voltage conditions on polluted polymer insulators
    HR Sezavar, N Fahimi, AA Shayegani
    IEEE Transactions on Power Delivery 37 (5), 3458-3468 , 2021
    2021.0
    Citations: 17
  • Method to design saturated iron‐core fault current limiters
    MA Baferani, N Fahimi, AA Shayegani
    IET Generation, Transmission & Distribution 13 (22), 5180-5187 , 2019
    2019.0
    Citations: 9
  • Investigating the failures of defected silicon rubber insulators in salt-fog chamber
    N Fahimi, MR Chalaki, MA Baferani, MR Tajik, AA Shayegani
    2018 IEEE Texas Power and Energy Conference (TPEC), 1-6 , 2018
    2018.0
    Citations: 16
  • A novel arrangement for improving three phase saturated-core fault current limiter (SCFCL)
    MA Baferani, MR Chalaki, N Fahimi, AA Shayegani, K Niayesh
    2018 IEEE Texas Power and Energy Conference (TPEC), 1-6 , 2018
    2018.0
    Citations: 30
  • Lifetime Evaluation of Outdoor Polymeric Insulators Based on Statistical Condition-Assessment Methods
    N Fahimi, M Goudarzi, AA Shayegani Akmal
    Available at SSRN 4901646 , 0

MOST CITED SCHOLAR PUBLICATIONS

  • A novel arrangement for improving three phase saturated-core fault current limiter (SCFCL)
    MA Baferani, MR Chalaki, N Fahimi, AA Shayegani, K Niayesh
    2018 IEEE Texas Power and Energy Conference (TPEC), 1-6 , 2018
    2018.0
    Citations: 30
  • Risk assessment of contaminated composite insulators in pre-flashover conditions
    HR Sezavar, N Fahimi, S Hasanzadeh, AAS Akmal
    Electric Power Systems Research 230, 110256 , 2024
    2024.0
    Citations: 20
  • Dynamic modeling of flashover of polymer insulators under polluted conditions based on HGA-PSO algorithm
    N Fahimi, HR Sezavar, AAS Akmal
    Electric Power Systems Research 205, 107728 , 2022
    2022.0
    Citations: 19
  • An improved dynamic multi-arcs modeling approach for pollution flashover of silicone rubber insulator
    HR Sezavar, N Fahimi, AA Shayegani-Akmal
    IEEE Transactions on Dielectrics and Electrical Insulation 29 (1), 77-85 , 2022
    2022.0
    Citations: 19
  • Flashover prediction of polymer insulators based on dynamic modeling of pollution layer resistance using ANN
    N Fahimi, HR Sezavar, AA Shayegani-Akmal
    IEEE Transactions on Dielectrics and Electrical Insulation 30 (1), 122-130 , 2022
    2022.0
    Citations: 18
  • A dynamic intelligent approach based on Gaussian function for prediction of the flashover voltage conditions on polluted polymer insulators
    HR Sezavar, N Fahimi, AA Shayegani
    IEEE Transactions on Power Delivery 37 (5), 3458-3468 , 2021
    2021.0
    Citations: 17
  • Investigating the failures of defected silicon rubber insulators in salt-fog chamber
    N Fahimi, MR Chalaki, MA Baferani, MR Tajik, AA Shayegani
    2018 IEEE Texas Power and Energy Conference (TPEC), 1-6 , 2018
    2018.0
    Citations: 16
  • Method to design saturated iron‐core fault current limiters
    MA Baferani, N Fahimi, AA Shayegani
    IET Generation, Transmission & Distribution 13 (22), 5180-5187 , 2019
    2019.0
    Citations: 9
  • A novel hybrid mathematical deep learning technique for early warning of flashover in composite insulators
    HR Sezavar, S Hasanzadeh, N Fahimi
    Scientific Reports 15 (1), 33448 , 2025
    2025.0
    Citations: 3
  • A techno‐economic model for enhancing PV hosting capacity through capabilities of smart inverters and soft open points
    R Golnazari, S Hasanzadeh, E Heydarian‐Forushani, HR Sezavar, ...
    IET Renewable Power Generation 18, 4233-4248 , 2024
    2024.0
    Citations: 3
  • Failure evaluation of outdoor polymeric insulators based on statistical condition-assessment methods
    N Fahimi, M Goudarzi, AA Shayegani-Akmal
    Electric Power Systems Research 238, 111134 , 2025
    2025.0
    Citations: 2
  • Biologically Inspired Survival Analysis Framework for Failure Monitoring of Composite Insulators Using Leakage Current
    N Fahimi, HR Sezavar
    Results in Engineering, 108742 , 2025
    2025.0
    Citations: 1
  • A Multi-Stage physics-informed neural network for optimal lightning protection design in solar power plants
    HR Sezavar, N Fahimi, H Karimi
    Electric Power Systems Research 256, 112879 , 2026
    2026.0
  • Numerical Investigation of Effects of Plasma Actuator Placement on Aerodynamic Parameters of NACA 0012 Airfoil
    N Fahimi, H Masoudi-Rad, MA Vaziri, M Ghadak
    Fluid Mechanics & Aerodynamics 12 (1), 65-74 , 2024
    2024.0
  • Lifetime Evaluation of Outdoor Polymeric Insulators Based on Statistical Condition-Assessment Methods
    N Fahimi, M Goudarzi, AA Shayegani Akmal
    Available at SSRN 4901646 , 0