Standards Development

Scope

This document gives the general requirements on composition, technical requirements, test items and requirements, inspection rules, marking, packaging, transportation, storage, on-site installation, acceptance criteria, and maintenance of the capacitance graded bushing tap adapter.

This document is applicable to the selection, testing, and application of the tap adapter of capacitance graded bushing for 550kV and below.

Purpose

With the rapid development of digital technology in power systems, the insulation state monitoring of capacitance graded bushings has garnered widespread attention, research, and application worldwide. Currently, manufacturers and users of capacitance graded bushings commonly employ bushing tap adapters to assess the internal insulation condition of bushings, including issues such as internal moisture, insulation degradation, and breakdown defects, with the aim of enhancing the monitoring capabilities of capacitance graded bushings.

However, during the application of capacitance graded bushing tap adapters, the following issues persist:

1. After the installation of bushing tap adapters on capacitance graded bushings, there is a lack of assessment methods for evaluating the impact of the tap adapter on the safety and performance of the bushing itself.

2. There is a multitude of tap adapter manufacturers, including bushing manufacturers, monitoring device manufacturers, universities, and others, each producing tap adapters with significant differences in structure, materials, and performance.

3. In the application of tap adapters, the absence of standardized testing and assessment methods in areas such as protection ratings, grounding reliability, safety, and performance poses challenges in ensuring effective monitoring, while also introducing significant safety risks to the bushings.

Therefore, this technical specification intends to provide recommendations for the composition, technical requirements, test items and requirements, inspection rules, marking, packaging, transportation, storage, on-site installation, acceptance criteria, maintenance, and other aspects of capacitance graded bushing tap adapters.