Composite Insulator Field Control via Varistor Particles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-voltage composite insulators face issues with uneven voltage distribution and local discharges due to stray capacitances and field increases, leading to reduced service life and damage to the protective layer, especially under weather-related influences.
Innovation Solution
Incorporating field-influencing particles, such as microvaristors made of doped zinc oxide, into specific sections of the protective layer of the insulator, particularly on the underside of shields and along the core, to manage voltage jumps and prevent local discharges by altering the electrical resistance characteristics in response to high voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If shielding electrodes are attached to live fittings to avoid excessive field increases, then local field increases are reduced, but device complexity increases
Solution Approach 1:
The patent combines the shielding electrode function with the protective layer by incorporating field-influencing particles directly into the protective layer material. This merging eliminates the need for separate shielding electrode attachments while maintaining the field control function, thus reducing device complexity while preserving reliability.
Solution Approach 2:
The protective layer is transformed into a composite material by adding field-influencing particles (such as metal oxide particles with semiconductive properties) to the elastomer matrix. This composite structure provides both the protective function and the field control function within a single integrated component.
2Reliability
If the protective layer is made of electrically insulating elastomer for insulating properties, then insulation performance is improved, but susceptibility to local discharges increases
Solution Approach 1:
The elastomer protective layer is converted into a composite material by incorporating field-influencing particles. These particles (such as metal oxides with semiconductive properties) modify the electrical characteristics of the insulating elastomer, enabling it to control electric field distribution while maintaining its insulating properties, thus preventing local discharges.
Solution Approach 2:
The field-influencing particles are distributed within the protective layer to create local variations in electrical properties. This allows different regions of the protective layer to have different electrical characteristics, with higher particle concentration in areas prone to field increases, thereby locally controlling the electric field to prevent discharges while maintaining overall insulation.
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 strategic placement of field-influencing particles effectively reduces local voltage increases and prevents discharges, enhancing the insulator's durability and service life by mitigating the impact of high-voltage stress and weather-related conductivity.
Implementation Method 1
field-influencing particles, such as microvaristors made of doped zinc oxide, into specific sections of the protective layer of the insulator, particularly on the underside of shields and along the core, to manage voltage jumps and prevent local discharges by altering the electrical resistance characteristics in response to high voltages
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is a composite insulator (1) having a core (2), in particular made of a fiber-reinforced duromer, and a protective layer (8) which surrounds the core (2) and is made in particular of an insulating elastomer. In some sections, especially on the bottom side of screens (4), the protective layer (8) specifically includes particles (7) that influence the field of the insulator (1).