Improving electric field stress using grading ring devices for insulated cross-arm

Abstract

Insulated cross-arms (ICA) allow for the compaction or enhancement of transmission lines. This study presents a comprehensive approach to designing and evaluating insulated cross-arm (ICA) grading devices to control electric fields for insulated cross-arms on a 132 kV lattice tower. A ring-shaped grading device is designed for the low voltage (LV) end of the insulator. A novel grading device is designed for the high voltage (HV) end—a single piece that controls the field for all four ICA members. Finite element analysis (FEA) simulations assess the electric field stress near the HV and LV ends of the ICAs, ensuring that it remains below the critical threshold of 18 kV/cm and effectively improves electric field stress at both ends of compression insulator by 70 % electric field stress at LV end and 80 % improved at HV end. The study outlines a thorough design methodology and provides valuable guidelines for utilising FEA in developing complex geometries. By adopting this approach, the researchers aim to enable the adequate compaction and upgrading of new and existing 132 kV overhead transmission lines, ultimately contributing to optimising power grid infrastructure. The findings of this study demonstrate the importance of integrating comprehensive design strategies and advanced simulation techniques to enhance the reliability and performance of ICA.

Keywords

• Overhead transmission lines
• Finite element analysis
• Insulated cross-arm
• Grading device
• HV and LV end