IEEE/IEC 65700-19-03-2025

This International Standard applies to outdoor and indoor bushings of any voltage used on DC systems, of capacitance graded or gas insulated types for use as components of liquid-filled converter transformers and smoothing reactors, as well as air-to-air DC bushings. It applies to both line commutated converter (LCC), as well as voltage source converter (VSC) technologies. This document does not apply to the following: • cable terminations (potheads); • bushings for instrument transformers; • bushings for test power supplies; • bushings applied with gaseous insulation (other than air at atmospheric pressure) external to the bushing; • bushings for industrial application; • bushings for traction application; • bushings for distribution class transformers. This document refers to IEC 60137 for general terms and conditions and defines the special terms used, operating conditions, ratings, test procedures as well as general mechanical and electrical requirements for bushings for DC application.

As this document is being developed jointly with IEC SC36A, this document will not contain a purpose clause.

Revision Standard - Active. This content has been transferred from the main text, since today's predominant bushing technology does not suffer from flashover during conditions of uneven wetting, in comparison to the earlier used ceramic insulators. Today's outdoor bushings in HVDC applications are made with composite insulators with silicon sheds with well proven hydrophobicity. Furthermore, there exist no verified test method with sufficient reproducibility between different laboratories. It is also difficult for operators to have full knowledge or clear data on how to arrange a test setup that reflects actual site conditions. Subsequently, uneven wetting test is not relevant for composite insulators. The testing may still be performed to outdoor bushings, particularly with ceramic insulators, but shall be agreed between purchaser and manufacturer.