HV Shielding Device With Inner Electrode Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high voltage insulation systems, such as those in HVDC transformers, face increased electric field stress due to the presence of gaps between insulating fluid and solid walls, which can lead to higher voltage drops and increased risk of corona discharge.
Innovation Solution
A high voltage shielding device with a solid outer insulating wall and strategically positioned inner electrodes, coated with insulating layers to enhance resistivity, eliminates gaps between the electrodes and the insulating wall, providing efficient radial and axial electric field shielding without creating additional oil gaps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If gaps are formed between insulating fluid and solid walls in high voltage insulation systems, then the insulation structure is simplified and easier to manufacture, but the electric field stress increases and voltage drops occur
Solution Approach 1:
The patent introduces an intermediary insulating barrier (pressboard or similar solid insulating material) between the electrode and the tank wall. This intermediary component fills the gap and provides continuous electrical insulation, preventing the formation of high-stress oil gaps while maintaining manufacturing simplicity. The barrier acts as a mediator that eliminates the harmful effect of gaps without complicating the overall structure.
2Reliability
If shielding electrodes are added to reduce electric field stress, then the insulation performance is improved, but the device complexity increases
Solution Approach 1:
The patent combines the shielding function with the existing tank wall structure by attaching the insulating barrier directly to the tank wall. This merging approach integrates the shielding function into the existing structure rather than adding separate complex shielding components, thereby improving insulation performance while minimizing increases in device complexity.
3Stress or pressure
If multiple insulation barriers are used to subdivide oil volume, then the voltage stress distribution is improved, but the manufacturing complexity and assembly difficulty increase
Solution Approach 1:
The patent extracts and eliminates the need for multiple complex insulation barriers by using a single continuous insulating barrier attached to the tank wall. This extraction approach removes unnecessary components while maintaining effective voltage stress distribution, thereby simplifying the overall insulation structure.
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 reduces electric field stress and enhances insulation efficiency by ensuring continuous contact between the outer electrode and the solid insulating wall, minimizing charge transfer and maintaining high voltage integrity in HVDC systems.
Implementation Method 1
the outer electrode may shield electric fields in the radial direction of the high voltage shielding device
Implementation Method 2
the first inner electrode may shield electric fields in the axial direction of the high voltage shielding device
Implementation Method 3
By providing the first inner electrode with a coating layer, the resistivity of the first inner electrode is increased compared to when it is not insulated
Implementation Method 4
In the transformer and in the bushing, typically transformer oil or similar dielectric fluid or gas is provided so as to insulate the power transformer and the bushing
Data Source
Figure 1a~1b
Figure 1c
Figure 2
AI summary
It is presented a high voltage shielding device (1) comprising a main body (2) having an enclosing outer solid insulating wall (2-1), an outer electrode (3) arranged on the solid insulating wall (2-1) providing a first level of insulation to the outer electrode (3), and a first inner electrode (4a) which is uninsulated or has a coating providing a second level of insulation, which second level of insulation is lower than the first level of insulation. The first inner electrode (4a) is oriented relative the outer electrode (3) in such a way that the first inner electrode (4a) mainly shields a component of an electric field (E2) which is perpendicular to a component of an electric field (E1) mainly shielded by the outer electrode (3).