Hybrid Circuit Breaker Current Path With Press-Fit Copper-Aluminum Joint
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Solution Overview
Problem
High and medium voltage circuit breakers in gas-insulated switchgear face challenges with bulky and costly current paths made from materials like aluminum and copper, which have low material utilization and high production costs.
Innovation Solution
A conductor arrangement using a tubular body conductor made from one metal material and a tubular contact conductor made from another, joined through longitudinal press-fitting, allowing for improved material utilization and reduced machining needs, with copper and aluminum used to combine cost-effectiveness and electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If aluminum current paths are used, then cost is reduced, but material utilization is low and the structure becomes bulky
Solution Approach 1:
The patent applies composite materials by joining aluminum and copper tubular conductors through press-fitting to create a hybrid current path. The aluminum tubular body conductor provides cost-effectiveness and structural strength, while the copper tubular contact conductor provides superior electrical conductivity. This composite structure resolves the contradiction by optimizing both material utilization and reducing bulkiness compared to pure aluminum conductors.
Solution Approach 2:
The current path is segmented into two distinct tubular conductor portions: an aluminum tubular body conductor and a copper tubular contact conductor. Each segment is optimized for its specific function - aluminum for structural integrity and cost-efficiency, copper for electrical performance. This segmentation allows improved material utilization by using only the necessary amount of each material where required.
2Reliability
If copper current paths are used, then electrical conductivity is improved, but production cost increases
Solution Approach 1:
The patent applies local quality by placing copper material specifically in the tubular contact conductor portion where high electrical conductivity is most critical for current interruption, while using aluminum for the tubular body conductor where structural strength and cost-effectiveness are prioritized. This localized material assignment optimizes electrical conductivity where needed while reducing overall production cost.
Solution Approach 2:
The hybrid aluminum-copper tubular conductor structure allows the system to benefit from copper's superior electrical conductivity in the contact region while using aluminum's cost advantages in the body region, thereby resolving the contradiction between electrical reliability and production cost.
3Ease of manufacture
If casting and machining are used for aluminum current paths, then manufacturing is achieved, but material utilization is low
Solution Approach 1:
The patent applies preliminary action by pre-forming the aluminum and copper conductors as tubular shapes before assembly through press-fitting. This preliminary tubular formation allows for better material utilization compared to traditional casting, as the tubular structure can be more efficiently formed and joined with minimal material waste.
Solution Approach 2:
The patent replaces traditional casting and machining processes with a press-fitting mechanical assembly process. Instead of casting aluminum current paths and then machining them, the invention uses pre-formed tubular conductors that are mechanically joined through press-fitting, significantly improving material utilization while maintaining manufacturing capability.
4Ease of manufacture
If traditional joining methods are used for copper and aluminum conductors, then connection is achieved, but electrical resistance is high
Solution Approach 1:
The patent replaces traditional mechanical joining methods (such as bolting or welding) with a press-fitting process that creates a tight interference fit between the aluminum and copper tubular conductors. This mechanical press-fitting ensures intimate contact between the dissimilar metals, minimizing interface resistance and improving electrical conductivity while maintaining ease of manufacture.
Solution Approach 2:
The patent applies parameter changes by controlling the dimensional parameters of the tubular conductors during press-fitting. By carefully selecting the outer diameter of the inner conductor and the inner diameter of the outer conductor, the press-fitting process creates optimal contact pressure and electrical contact area, thereby minimizing electrical resistance at the aluminum-copper interface.
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 provides a cost-efficient and high-strength joint with low electrical resistance, suitable for automation and maintaining mechanical integrity during temperature fluctuations, while reducing material usage and production costs.
Implementation Method 1
a tubular end portion of the tubular body conductor is mechanically and electrically joined with a tubular end portion of the tubular contact conductor in an circumferential overlap region formed by longitudinally press-fitting one of the tubular body conductor and the tubular contact conductor into the other one of the tubular body conductor and the tubular contact conductor
Implementation Method 2
during the press-fitting, the materials are pressed into each other at molecular level which provides a secure mechanical fit with superior electrical conducting properties
Data Source
AI summary
A conductor arrangement for a circuit breaker interrupter, the conductor arrangement including: a tubular body conductor including a first metal material, and an at least partly tubular contact conductor including a second metal material; wherein a tubular end portion of the tubular body conductor is mechanically and electrically joined with a tubular end portion of the tubular contact conductor in an circumferential overlap region formed by longitudinally press-fitting one of the tubular body conductor and the tubular contact conductor into the other one of the tubular body conductor and the tubular contact conductor, wherein the outer one of the tubular end portions of the tubular body conductor and the at least partly tubular contact conductor at the overlap region includes copper and the inner one includes aluminum.