Developments of high voltage porcelain post-insulators

The main purpose of this work was to investigate the development trends of high voltage porcelain post insulators over the last decades. It also shows an analysis of the performance of a contemporary design of a shorter nonstandard layout and its agreement with the IEC standards. Despite of high demanding requirements on Ceramic Solid Core Post Insulators, the economical aspect becomes more and more important. Therefore the objective of insulator design is to develop a technically and economically optimized HV component, with a high grade of reliability over decades. If some parameters can be optimized like, arcing distance and length of the insulator, maximizing the mechanical strength and stiffness, minimizing the core diameter, maximizing the form factor and finding an optimal shed profile, material can be saved and therefore weight can be reduced also and costs. Due to a more sophisticated manufacturing process of high voltage insulator, they can be produced in a bigger length in one piece and thinner sheds than 40 years ago. The result of these measures are a longer arcing and creepage distance, less weight and most of all less electrically conducting parts. 40 years ago, the column design for an 800kV AC post insulator was a stack of 6 insulators, compared to two insulators nowadays. This work reflects the different developments of design between the past and in these days, because the question was raised: do post insulators need to have the same total height than 40 years ago despite of an improvement of manufacturing them.