3D electric field computation of a composite cross-arm

The use of composite insulators for overhead transmission lines has increased in the past decade. Various designs and models are now available for a wide range of voltages. The 3D Finite Element Analysis electric field distribution of such composite insulators has been of considerable interest due to its differences to ‘conventional’ glass or ceramic insulators. Results of such analysis are now widely available. The present paper presents and analyses the electric field distribution around a composite insulator, which is intended to replace both existing high voltage insulators and the cross-arms of transmission towers. The complex geometry of the composite cross-arm, which includes four separate insulator strings and different shed profiles across these members all connected to a common metallic nose cone, make it difficult to model in any 3D Finite Element Analysis package. The present paper will evaluate the electric fields on such a composite cross-arm, in regards to the areas of high field enhancement.