STRUCTURAL ANALYSIS OF 420 kV POLYMER-HOUSED SURGE ARRESTER

The present paper discusses about the structural analysis of polymer-housed surge arrester (SA) along with its support structure for ultra-high voltage applications. The main objective of the work is to study the effect of various geometric parameters on the static and dynamic responses of the SA assembly and hence to finalize the mechanical design of the integrated equipment–structure combination. As it is cumbersome to generate detailed finite element model and conduct iterative analysis manually, an automation tool has been developed in ANSYS using ANSYS Parametric Design Language (APDL) to ease numerical modelling and structural analysis. Here, the input parameters are entered through a user interface developed in VB.Net. Sensitivity analyses have been conducted to compute the effect of various parameters on the static and dynamic responses of the polymer-housed SA assembly. The analyses results indicate that cantilever deflection of polymer-housed SA is most sensitive to thickness variation of flange followed by insulator tube thickness and elastic modulus of a tube material made of fibre-reinforced polymer. A 420 kV SA assembly finalized based on structural responses is further analysed to compute voltage distribution across metal oxide blocks and electrostatic field across polymer housing.