In-Line Disconnect Switch Blade With Internal Corona-Shielded Cooling Fins
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Solution Overview
Problem
Existing motorized in-line high voltage air break disconnect switches face challenges with heavy switch blades due to increased copper requirements for higher current ratings, leading to operational difficulties and high costs, and the incorporation of manual operation mechanisms is cumbersome.
Innovation Solution
A motorized in-line high voltage air break disconnect switch with a rotating switch blade featuring two parallel copper conductors and internal cooling fin units positioned within the air gap between the conductors, which are shielded from corona stress by rounded edges, reducing conductor size and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If copper conductor size is increased to achieve higher current ratings, then current carrying capacity is improved, but weight of the switch blade increases making motor operation unreliable
Solution Approach 1:
The patent divides the solid copper conductor into multiple parallel copper conductors (at least two) with air gaps between them. This segmentation reduces the weight of the switch blade while maintaining the current carrying capacity, as the air gaps replace some of the copper material. The segmented structure allows the motor to reliably operate the lighter switch blade while still achieving the required current rating through the combined capacity of multiple conductors.
Solution Approach 2:
The patent creates a composite structure by combining copper conductors with air gaps (air being a non-conductive, weightless material). This composite arrangement maintains electrical conductivity through the parallel copper elements while reducing overall weight compared to a solid copper conductor of equivalent current capacity. The air gaps between conductors contribute to weight reduction without significantly compromising current carrying ability.
2Power
If copper conductor size is increased to achieve higher current ratings, then current carrying capacity is improved, but cost of copper increases significantly
Solution Approach 1:
The patent segments the copper conductor into multiple smaller parallel conductors with air gaps between them. This segmentation reduces the total quantity of copper required while maintaining the current carrying capacity, as the air gaps replace copper material. The combined cross-sectional area of the segmented copper conductors provides the necessary current rating with less total copper than a solid conductor would require.
Solution Approach 2:
The patent uses multiple parallel copper conductors instead of a single large conductor. This copying approach distributes the current carrying function across multiple smaller elements, reducing the total copper quantity needed while achieving the same or better current rating through the combined capacity of the parallel conductors.
3Temperature
If cooling fin units are added to conductors, then heat dissipation is improved, but corona stress occurs between fins and ground plane
Solution Approach 1:
The patent nests the cooling fin units within the air gaps between the parallel copper conductors. This nesting arrangement allows the cooling fins to be positioned inside the space already created by the segmented conductor structure, eliminating the need for additional external space. The fins are contained within the conductor assembly rather than extending outward, which prevents corona discharge to the ground plane.
Solution Approach 2:
The air gaps between the parallel copper conductors serve as an intermediary space that accommodates the cooling fin units. These air gaps, which are necessary for the segmented conductor structure, double as housing for the cooling fins. The copper conductors themselves act as shields, protecting the cooling fins from direct exposure to the external electric field that would cause corona discharge.
4Reliability
If manual hook operation is incorporated for backup operation, then operational reliability is improved, but device complexity and ease of operation deteriorate
Solution Approach 1:
The patent reduces the need for manual intervention by optimizing the motor's ability to operate the switch blade. Through weight reduction achieved by segmenting the copper conductors and using air gaps, the motor can reliably operate the switch blade without requiring a manual backup mechanism. The switch blade is designed to be self-sufficient with motor-only operation, eliminating the complexity of manual hook operations while maintaining reliability through improved motor performance on the lighter blade.
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
Enables reliable operation with higher current ratings up to 3000 A without manual intervention, while maintaining compliance with IEEE standards by preventing corona stress and reducing material costs.
Implementation Method 1
Heat conducting cooling fin units are attached to an inner side of at least one of the conductors
Implementation Method 2
cooling fin units positioned entirely within the air gap between the conductors
Implementation Method 3
which include rounded top and bottom edges. Corona electrical stress between the heat conducting cooling fins and a ground plane when the switch is in a horizontal closed conductive switch position is prevented
Data Source
AI summary
A high voltage motorized in-line air break disconnect switch having a rotating switch blade with two parallel elongated rectangular metal conductors having rounded top and bottom edges include a gap between the conductors. Heat conducting cooling fin units are attached to an inner side of at least one of the conductors and are positioned entirely within the gap. No part of each cooling fin unit extends above the rounded top edge or below the rounded bottom edge of a conductor to which it is attached. Corona electrical stress between the heat conducting cooling fins and a ground plane is prevented. The two conductors act as electric shields to prevent corona even with the inclusion of the cooling fin units positioned within the gap between the two conductors, permitting a reduction in the size and weight of the conductors compared to conductors without the cooling fin units.