Tulip Contact Decoupling for Pre-Insertion Resistor Switchgear

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Solution Overview

Problem

Existing contact arrangements for Pre-Insertion Resistors in high-voltage Gas-Insulated Switchgear circuit breakers are prone to mechanical failure due to high forces and speeds, leading to unreliable connection and disconnection cycles, which can result in the movable contact remaining connected and causing serious consequences.

Innovation Solution

A contact arrangement featuring a control rod with a tulip having resilient fingers and a movable contact with a latching ring, where the tulip deforms from a first to a second diameter to decouple from the control rod when resistance exceeds a predetermined value, allowing reliable temporary connection and disconnection with the Pre-Insertion Resistor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a toroidal spring is used to mechanically couple the control rod to the movable contact, then the contact arrangement can achieve connection and disconnection of the PIR, but the mechanical coupling is prone to failure due to large forces and high speeds

Engineering Contradiction:

Improvereliability of connection and disconnectionVSAvoidmechanical strength under high force and speed

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The tulip structure incorporates resilient fingers that can dynamically deflect inwards to reduce diameter, allowing the control rod to pass through during normal operation while maintaining mechanical coupling. This dynamic adaptation enables the system to withstand high forces and speeds without mechanical failure, resolving the contradiction between reliability and strength.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The tulip's diameter is changed from a first diameter (when fingers are outward) to a second diameter (when fingers deflect inwards). This parameter change allows the structure to accommodate the control rod during coupling while providing mechanical strength during operation, thereby improving reliability without compromising strength.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the movable contact remains connected to the PIR due to mechanical failure, then the circuit breaker cannot operate safely, but the existing contact arrangement cannot ensure extended cycle operation

Engineering Contradiction:

Improvesafe operation of circuit breakerVSAvoidendurance for extended cycles

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The resilient fingers of the tulip are pre-configured to deflect inwards under load, providing a cushioning effect that prevents mechanical failure. This beforehand cushioning ensures that the movable contact can reliably disconnect from the PIR after the temporary connection period, enabling safe operation and extended cycle endurance.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The mechanical coupling mechanism provides feedback through the resilient fingers' deflection. When the movable contact remains connected too long or excessive force is applied, the fingers deflect to reduce the tulip's diameter, causing the control rod to pass through and decouple the movable contact. This feedback mechanism ensures safe operation and prevents failure during extended cycles.

Inventive Principle:

Principle #23Feedback

3Reliability

If the tulip deforms from first diameter to second diameter to decouple the movable contact, then the contact arrangement achieves reliable disconnection, but the structure becomes more complex

Engineering Contradiction:

Improvereliability of decoupling mechanismVSAvoidstructural complexity of tulip and latching ring

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The tulip is segmented into multiple resilient fingers that can independently deflect inwards. This segmentation allows the structure to achieve the diameter reduction function while maintaining a relatively simple overall design. The fingers work together to provide reliable decoupling without requiring complex mechanisms.

Inventive Principle:

Principle #1Segmentation

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 proposed contact arrangement enhances mechanical endurance and reliability, enabling the circuit breaker to withstand extended cycles without mechanical failure, ensuring safe and efficient operation of the Pre-Insertion Resistor.

Implementation Method 1

the fingers arranged to be deflected inwards such that the tulip is deformed to a second diameter

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3748658B1Contact arrangement for pre-insertion resistor

Publication Date: 2022.03.23 GENERAL ELECTRIC TECH GMBH

Figure 1~2
Figure 3~4

AI summary

The invention concerns a contact arrangement (50) for a Pre-Insertion Resistor (PIR) wherein a control rod (20) is arranged to move a movable contact (30), against the force of a biasing member (18), into temporary connection with a PIR. The control rod (20) comprises a tulip (21) with a plurality of resilient fingers (24) and having a first diameter where it is able to mechanically couple to a latching ring (31) on the movable contact (30), and a second diameter where the tulip (21) is deformed with the fingers (24) deflected inwards, once the resistance to movement exceeds a predetermined value, wherein the latching ring (31) is able to pass over the tulip (21) to decouple the movable contact (30) from the control rod (20). The contact arrangement (50) is particularly suited for a PIR arranged for connection in parallel to the interrupter of a gas-insulated switchgear (GIS) circuit breaker.