Switchgear Turn and Twist Mechanism for High Voltage Bus Transfer

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing switchgear turn and twist mechanisms have limited scope for higher degree of rotation, are bulky, and create dielectric problems, which are inadequate for high voltage applications above 100 kV and current ratings above 2000 A, particularly for bus transfer switching.

Innovation Solution

A switchgear with a turn and twist mechanism comprising a cylindrical pipe that turns about a first axis and twists about a second axis, driven by a mechanism involving a driving base, floating carrier, and driving pin arrangement, allowing for greater rotational flexibility and stability, thereby enabling effective engagement and disengagement of contacts without dielectric issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If lever/clamp arrangements are used for twisting motion, then the mechanism is structurally simple, but the degree of rotation is limited and the structure becomes bulky

Engineering Contradiction:
Improvedegree of rotationVSAvoidmechanism structure
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The mechanism is divided into two independent rotation systems: turning motion about the first axis (vertical axis through the insulator) and twisting motion about the second axis (longitudinal axis of the current path pipe). This segmentation allows each axis to achieve its required rotation independently, enabling greater overall degree of rotation without requiring a single complex mechanism

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a single-axis rotation mechanism to a dual-axis rotation mechanism. By adding rotation about a second axis (longitudinal axis of the pipe) in addition to the first axis (vertical axis), the system achieves greater rotational flexibility and degree of rotation, solving the limitation of conventional single-axis mechanisms

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If lever/clamp arrangements are used for twisting motion, then the mechanism is compact, but dielectric problems occur in high voltage applications

Engineering Contradiction:
Improvedielectric integrityVSAvoidmechanism structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The driving insulator rod acts as an intermediary component that transmits rotational motion from the operating mechanism to the current path pipe while maintaining dielectric isolation. The insulator rod with its high dielectric strength allows the mechanism to operate reliably in high voltage applications (100 kV and above) by preventing electrical breakdown between live parts and ground

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The mechanism uses composite construction combining the driving insulator rod (ceramic or composite insulating material) with the current path pipe (conductive material). This composite structure provides both mechanical functionality and dielectric protection, enabling the mechanism to withstand high voltage stresses while maintaining structural integrity

Inventive Principle:
Principle #40Composite materials

3Adaptability or versatility

If higher degree of rotation is achieved for bus transfer switching, then switching capability is improved, but the mechanism becomes bulkier

Engineering Contradiction:
Improvebus transfer switching capabilityVSAvoidmechanism volume
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The mechanism employs dynamic rotation about two axes to achieve the required degree of rotation for bus transfer switching. By allowing the current path pipe to rotate dynamically about both the first axis (turning) and second axis (twisting), the system achieves high adaptability for different switching configurations without requiring excessive mechanical clearance or bulky structure

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3753036B1Center turn and twist mechanism of a switchgear
Publication Date: 2021.07.14 HITACHI ENERGY SWITZERLAND AG
  • EP3753036B1 patent drawingFigure 1~2
  • EP3753036B1 patent drawingFigure 3~5
  • EP3753036B1 patent drawingFigure 6~7

AI summary

The invention relates to a switchgear having a turn and twist mechanism. The switchgear has a contact system for electrical current conduction and bus transfer switching. The contact system has a fixed contact assembly and a movable contact assembly. The turn and twist mechanism drives the movable contact assembly for engagement / disengagement of the movable contacts with the fixed contacts. The turn and twist mechanism comprises a cylindrical pipe and a driving assembly. The driving assembly comprises a driving base, a floating carrier and a driving pin arrangement, for driving the cylindrical pipe for the engagement / disengagement. The driving base drives the floating carrier for turning the cylindrical pipe about a first axis, and drives the driving pin arrangement for twisting the cylindrical pipe about a second axis.