HVDC Bypass Switch Insulating Cover for Noise and Isolation

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Solution Overview

Problem

Existing bypass switches in HVDC transmission systems face challenges with insulation performance between the actuator and bus bar, requiring additional insulation design and potentially noisy firing signals due to the actuator's proximity to high-pressure current paths, and the need for expensive springs with large spring constants.

Innovation Solution

The bypass switch incorporates an insulating cover between the actuator and the second bus bar, along with a cylindrical movable part extension rod to accommodate a contact spring, eliminating the need for complex insulation designs and allowing the use of commercially available springs, thus improving insulation and reducing noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the actuator is disposed adjacent to the second bus bar to enable compact structure, then the device complexity is reduced, but the insulation performance deteriorates due to proximity to high-pressure current paths

Engineering Contradiction:
Improvestructure compactnessVSAvoidinsulation performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

An insulating cover is introduced as an intermediary component between the actuator and the second bus bar. This insulating cover is coupled to the second bus bar and extends to cover the actuator, providing electrical insulation while allowing the actuator to remain in its compact position adjacent to the bus bar for operational efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the actuator is placed near the high-pressure current path for compact design, then the device complexity is reduced, but noise generation increases due to electromagnetic interference

Engineering Contradiction:
Improvestructure compactnessVSAvoidnoise generation
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The insulating cover serves as a shielding intermediary between the actuator and the high-pressure current path in the second bus bar. This cover reduces electromagnetic interference and noise generation while maintaining the compact structural arrangement, allowing the actuator to operate close to the bus bar without excessive noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a spring with large spring constant is used to ensure sufficient contact pressure, then the contact reliability is improved, but the manufacturing cost and device complexity increase

Engineering Contradiction:
Improvecontact pressureVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of using a spring with an excessively large spring constant, the patent modifies the spring parameter within a reasonable range (0.5 to 2.0 N/mm) and compensates by optimizing the spring installation structure. The spring is installed in a groove in the movable part extension rod, allowing sufficient contact pressure to be achieved with a commercially available spring of moderate specifications, reducing manufacturing cost and complexity.

Inventive Principle:
Principle #35Parameter changes

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 design enhances insulation, reduces noise, and enables faster operation with improved stroke control, using standard springs and minimizing component weight.

Implementation Method 1

The maintenance of the open state of the high-speed bypass switch is made by magnetic force of a permanent magnet 4. The movable contact 21 is separated from the fixed contact 22 as the latch plate 32 is attracted to the permanent magnet 4 by the magnetic force of the permanent magnet 4 disposed adjacent to the actuator 52

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 2

An actuator (inflator) 52 is provided as a driving source for operating the movable contact 21. The actuator 52 is exploded by an electrical signal to supply driving force for moving the movable contact 21

Methodology Applied
Scientific EffectElectrical signal to mechanical force conversion:

Implementation Method 3

a spring 48 serves to push the movable contact 21 with a specific force while the contacts 21 and 22 are in the closed state. The spring 48 serves to apply contact pressure (or force) to prevent the contacts 21 and 22 of the vacuum interrupter 2 from being separated from each other

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP3979286B1Bypass switch
Publication Date: 2025.10.15 LS ELECTRIC CO LTD
  • EP3979286B1 patent drawingFigure 1
  • EP3979286B1 patent drawingFigure 2
  • EP3979286B1 patent drawingFigure 3

AI summary

The present invention relates to a bypass switch and, more specifically, to a bypass switch used in a super-high voltage direct current transmission sub-module. A bypass switch according to one embodiment of the present invention comprises: a case in which a hollow part is formed; a first bus bar coupled to the front end of the case; a second bus bar coupled to the rear end of the case; a fixing contact which is provided in the hollow part and which is connected to the first bus bar; a movable contact which is provided in the hollow part, and which is connected to the second bus bar so as to come into contact with or be separated from the fixing contact; an insulating cover which is coupled to the rear surface of the second bus bar, and which has an accommodation part therein; a movable part extension rod which is provided on the accommodation part and which is coupled to the movable contact; and an actuator which is provided on the rear part of the insulating cover, and which provides power for moving the movable part extension rod.