High-Voltage Connector J-Ring Insulating Layer Flashover
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Solution Overview
Problem
High-voltage electrical connectors in underground distribution systems face flashover issues due to partial vacuum-induced dielectric strength reduction, with existing solutions like additional insulation, vented bushings, and J-ring designs having limitations such as vent clogging and material removal affecting vacuum relief.
Innovation Solution
The implementation of a J-ring design with an insulating layer over high-electrical-stress areas on the grounding shield, combined with injection molding of insulative rubber to create non-conductive portions, enhances electrical properties and prevents arcing by manipulating electric fields and air flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional insulation is placed over the grounding shield, then flashover resistance is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent applies insulation selectively only at the high-electrical-stress area where the cuff interfaces with the bushing, rather than providing complete insulation coverage. This localized approach maintains flashover resistance where needed while reducing overall device complexity and material usage.
Solution Approach 2:
The patent introduces an intermediary insulating layer positioned between the metal cuff and the grounding shield at the critical interface area. This intermediary component prevents direct electrical contact and flashover without requiring complete insulation of the entire assembly.
2Reliability
If insulating layer is placed over grounding shield, then flashover resistance is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent combines the insulating layer with the grounding shield assembly during the molding process, creating an integrated component. This merging ensures proper positioning and alignment without requiring separate precision assembly steps, thereby maintaining flashover resistance while reducing manufacturing precision requirements.
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
This approach significantly reduces flashover incidents, achieving a 90% success rate in OIACWT tests, compared to 20% with J-ring alone and 0-5% with insulation alone, demonstrating synergy and improved performance.
Implementation Method 1
the dielectric strength of that air is also lowered, as described in Paschen's curve. The lowered dielectric strength of the air leads to lowered resistance and sometimes, arcing
Implementation Method 2
it was discovered that flashover is caused by a decrease in the dielectric constant of the air trapped in the assembly due to a partial vacuum during loadbreak operations
Data Source
AI summary
A high-voltage electrical connector system comprises a bushing with a longitudinal axis, a shoulder, a first end, and a second end, wherein the shoulder is between the first end and the second end; a ring arranged circumferentially around a first outside diameter of the bushing, the ring disposed between the shoulder and the second end, the ring including a channel therein defining a circumferential extension extending axially toward the first end; a ground shield disposed on a second outside diameter of the bushing between the ring and the second end, the ground shield comprising one or more of conductive material and semiconductive material; and an insulative portion adjacent the ring and disposed circumferentially over a portion of the ground shield.