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Development of the World’s Lightest & Slimmest 380 kV Porcelain Long Rod Insulators for Ultra-High Pollution Environments
ITG’s innovative porcelain long rod insulator redesign combats specific environmental challenges in the Middle East.
Background
In regions such as the Middle East, particularly in Kingdom of Saudi Arabia, extreme environmental conditions result in rapid accumulation of sand and pollution on high-voltage transmission infrastructure. To address this, in 2023, Insulation Technology Group initiated a design standardisation project focused on enhancing porcelain long rod insulators for 380 kVac overhead transmission lines.s.
Objective
The project aimed to optimise the existing Generation I insulator design to improve pollution performance, reduce physical dimensions, and unify insulator specifications across different creepage classes, leading to the development of Generation II insulators.
Design Improvements
The Generation II design preserved the same creepage class (for example, in the case of 50 mm/kV) but introduced several key enhancements:
- Increased insulation length by 8.23% (from 1700 mm to 1840 mm)
- Increased arcing distance by 7.12% (from 1545 mm to 1655 mm)
- Decreased unit weight by 9.70% (from 62.9 kg to 56.8 kg)
- Reduced surface area by 9.61%
These changes resulted in a slimmer and lighter product without compromising mechanical performance.
Testing and Validation of the 380kV Porcelain Long Rod Insulators
Performance was evaluated through a series of pollution and dielectric tests, including:
- Salt-fog and solid-layer contamination tests (IEC 60383 – Cl. 5 & Cl. 6 – CIGRE TB 691)
- Wet a.c. flashover and withstand voltage tests (IEC 60383)
Comparison of quick flashover tests (as salt-fog tests). Source: PPC Insulators
Comparison of quick flashover tests (as salt-fog tests). Source: PPC Insulators
Graphical plot for withstand voltage test with increase in voltage steps on Generation II design. Source: PPC Insulators
Outcome
The Generation II insulator design demonstrated improved electrical performance and continued mechanical efficiency under both clean and polluted conditions. It supports harmonisation across multiple creepage and strength classes, aligning with IEC 60815-2 and Saudi Electricity Company’s TMSS standards. This innovation represents a significant advancement in insulator technology for high-pollution in high-voltage environments.
