Partial discharge analysis in Class F and H epoxy resin insulators: void size impact on high-voltage performance
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Abstract
Partial discharge (PD) describes localized electrical discharges that occur within insulating materials. Owing to its exceptional electrical and thermal properties, epoxy resin is widely utilized as an insulation medium in electrical systems. Insulation classes F and H are categorized based on their thermal endurance ratings, with insulation degradation remaining a primary cause of power equipment failures. PD-based diagnostic tools enable precise condition monitoring of insulation systems, critical for reliability. Voids inherent in solid dielectric materials often initiate insulation breakdown, particularly when PD activity originates within enclosed cavities. This paper investigates the relationship between void dimensions and insulation lifespan in dry-type transformers, focusing on PD-induced degradation within internal voids. Class-F and Class-H epoxy resin samples, incorporating artificial circular voids of 2 mm, 3.5 mm, and 4 mm diameters, were analyzed in collaboration with ESSENNAR R&D Center using IEC60270-compliant testing protocols. Key findings reveal that increased void size correlates with reduced partial discharge inception voltage (PDIV) and heightened discharge magnitudes and repetition rates. While observed discharges remained below the IEC60270 threshold of 140 pC, PDIV values approached the critical 10 pC limit in larger voids, underscoring the impact of void geometry on insulation performance. These insights emphasize the need for stringent quality control in epoxy resin applications to mitigate PD risks.
Acknowledgments
We sincerely acknowledge the invaluable support and contributions of ESSNNER Transformer, Hyderabad, Telangana, India and Presidency university Bengaluru, India in this research. Their assistance and encouragement were integral to the successful completion of this work.
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Research ethics: This study was conducted in full compliance with ethical standards and guidelines, ensuring the integrity and credibility of the research.
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Informed consent: The authors provided informed consent prior to their involvement in the study. Their rights and confidentiality were respected at all times.
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Author contributions: Each author has contributed significantly to the development, analysis, and writing of this manuscript.
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Use of Large Language Models, AI and Machine Learning Tools: Not applicable.
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Conflict of interest: No conflict of interest exists among the authors concerning the content of this study.
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Research funding: Not applicable.
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Data availability: All data supporting the findings of this study are available and can be accessed upon reasonable request.
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Articles in the same Issue
- Frontmatter
- Research Articles
- A new step up nine level switched capacitor multilevel inverter
- A novel power flow control unit for V2G and G2V mode of electric vehicles
- Partial discharge analysis in Class F and H epoxy resin insulators: void size impact on high-voltage performance
- Review of sub-synchronous oscillation (SSO): from historical challenges to modern inverter-based renewable energy sources
- A study of wireless power transfer using series-series magnetic resonant coupling topology
- A novel triple boost inverter with high efficiency for grid connected applications
- Optimal capacity of renewable energy and methanation system in a remote island model considering frequency fluctuation
- A robust seven-level fault tolerant hybrid cascaded H-bridge inverter
- Multi-objective predictive maintenance optimization of electric energy meters based on LSTM-XGBoost and modified firefly algorithm
- Applying the concept of load modeling with multiple impact factors in suburban field
- Modeling the cell temperature of rooftop PV panels under dynamic environmental conditions: implications for power output and temperature in shaded areas
- Leveraging extra high voltage grid supplies for the dynamic performance analysis of large power transformer in short-circuit scenario
- A simplified multi-mode model predictive current control method for a novel neutral-point-connected open-end winding induction motor driven system
