Design of rotating wheel dip test system for standard tracking and erosion testing of polymeric insulators

Summary

Surface tracking and erosion – the irreversible degradation on the surface of an insulator – can lead to significant increase in surface conduction ultimately leading to failure of an insulator. Polymeric insulation (non-ceramic insulators, NCI) have numerous advantages over traditional ceramic insulators, including superior hydrophobicity correlating to reduced surface leakage current. However, polymers are prone to degradation and aging resulting from electrical, chemical and environmental stress. Tracking and erosion tests expose test samples to artificial harsh environments to verify the suitability of insulator designs and materials (detect weaknesses) by applying continuous, cyclic or combined stresses. Various forms of tracking and erosion testing exist – incline plane (IEC 60587), spray (method 1) or rotating wheel dip tests (RWDT, method 2). Numerous standards such as CSA C310-09, ANSI/NEMA C29.13 and IEEE Std. C37.41, and IEC 62730 define the required conditions and procedures for rotating wheel dip tests – saline solution, voltage stress, exposure cycles, recovery periods, etc. However, instructions for how to build such setups are not given. The Mississippi State University High Voltage Laboratory is constructing four independent setups for different insulator types and voltage ratings. Simplicity of design and cost effectiveness are priorities. This paper presents the components, configurations, and alternatives for constructing a cost effective stand-alone RWDT system for tracking and erosion testing of NCIs as well as compares the procedures and acceptance criteria presented in various standards.

Additional informations

Authors

OHTAKE

Keywords

Tracking and Erosion, Rotating Wheel Dip Test, Insulators, Standards