DC Gas-Insulated Insulator Contacting Element Field Coordination
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Solution Overview
Problem
In DC gas-insulated electrical systems, charge accumulation on high-voltage insulators leads to surface potential distortion and reduced breakdown strength due to electric field distribution differences compared to AC systems, necessitating improved surface conductivity and reliable contact management to prevent streamer inception and insulation breakdown.
Innovation Solution
A high-voltage insulator arrangement with a contacting element having a gradient angle and specific height reduction, enhancing electric field distribution by introducing a tangential field component, ensuring proper potential connection and current carrying capability, and minimizing the impact of particles in the insulating gas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the insulator surface is treated to increase electrical conductivity, then charge accumulation is reduced, but the electric field distribution becomes distorted leading to streamer inception
Solution Approach 1:
The patent applies different surface treatments to different regions of the insulator. The high-voltage side receives a surface treatment with higher conductivity to prevent charge accumulation, while the ground side has lower conductivity to maintain proper field distribution. This local differentiation resolves the contradiction by allowing each region to have the conductivity characteristics needed for its specific electrical stress conditions.
Solution Approach 2:
The patent changes the surface conductivity parameter through chemical treatment (fluorination) to achieve the desired electrical properties. By controlling the degree and distribution of surface treatment, the patent optimizes the balance between preventing charge accumulation and maintaining proper field distribution, thereby resolving the contradiction between reliability and harmful field distortion.
2Ease of manufacture
If a uniform surface treatment is applied to the entire insulator, then manufacturing is simplified, but the electric field distribution cannot be optimized for both high-voltage and ground sides
Solution Approach 1:
The patent implements local quality differentiation by applying surface treatment only to specific regions (high-voltage side) or with varying intensity across different zones. This approach maintains manufacturing feasibility while achieving the complex electrical performance requirements, as the treatment can be applied in stages or with spatially varying parameters rather than requiring completely different processes.
3Reliability
If the insulator surface has high conductivity to collect leakage currents, then charge accumulation is prevented, but particles in the insulating gas are attracted to the surface causing degradation
Solution Approach 1:
The patent applies high surface conductivity treatment specifically on the high-voltage side where charge accumulation is the primary concern, while maintaining lower conductivity on the ground side where particle attraction would be more problematic. This spatial differentiation allows the system to collect necessary leakage currents while minimizing particle attraction to the insulator surface.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively coordinates the electric field to collect leakage currents and prevent particle-induced insulation degradation, maintaining reliable operation and insulation integrity in DC gas-insulated systems.
Implementation Method 1
The electrical conductivity of the insulator surface is higher than the electrical conductivity of the insulator body, in particular when a high electrical field is present along the insulator surface
Implementation Method 2
A second height of the contacting element at the end face is lower than the first height and the height of the contacting element from the first height to the second height reduces at a gradient angle such that a gas side face of the contacting element is slanted
Data Source
Figure 1a
Figure 1b
Figure 1c
AI summary
The disclosure relates to a high-voltage insulator (100) for insulation of a DC conductor of a gas-insulated electrical system, and to a gas-insulated electrical system comprising a high-voltage insulator. The high-voltage insulator (100) comprises an insulator body (50) and an insulator surface (51), wherein the electrical conductivity of the insulator surface (51) is higher than the electrical conductivity of the insulator body (50); and a contacting element (30). The contacting element (30) comprises an insulator side face (31) having a first height (hres) for connecting a predetermined length of the insulator surface (51) to a definite potential, the contacting element (30) further extending by a total width (w) in a width direction away from the insulator surface (51) up to an end face (32). A second height (hend) of the contacting element (30) at the end face (32) is lower than the first height (hres).