Optimization of Transmission Line Structures Using Braced Post Insulators

Due to advancements in silicon and fiberglass rod technology there are now seemingly limitless options to customize high voltage braced post insulator designs for new or existing poles and lattice structures. This paper covers the optimization process for transmission line design using braced post insulation for 138 and 240 kV circuits and reviews examples of custom applications where braced post insulators have been used for the purpose of clearance mitigation without replacing structures. This paper will break down the steps of line optimization and benefits of braced post insulators for new line construction compared to traditional pole and crossarm designs. Some of the benefits that will be covered include reduced construction and assembly time, reduced hardware requirements, better contamination resistance, bird perch reduction, reduced right-of-way requirements, smaller structure footprint, and fire hardening. Also discussed in the paper is the process of modifying existing structures with custom compact braced post insulator designs to increase clearance without losing full functionality of the structure. This paper will provide examples where traditional cross arms with suspension insulators and lattice tower arms have been replaced with specialized braced post insulator assemblies to mitigate clearance violations in Alberta, Canada. Some of the drawbacks of braced post insulators such as reduced longitudinal capacity and increased galloping risk, are also summarized in this paper.