Three-Position Switch Assembly Position Indication

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Solution Overview

Problem

Current high voltage switchgear systems require complex mechanical setups and additional equipment to generate reliable position indication signals for motor control, with existing solutions prone to signal loss during power outages or manual alterations.

Innovation Solution

The implementation of micro switches and auxiliary switches, where auxiliary switches are wired in series or parallel to micro switches, generating continuous and precise position indication signals for motor control, utilizing a control unit that can recognize the exact position of the movable contact piece.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If micro switches are used for precise position indication, then measurement precision is improved, but device complexity increases due to the need for multiple individual switches and complex control circuits

Engineering Contradiction:
Improveposition indication precisionVSAvoidcontrol circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple micro switches (first micro switch for isolator position, second micro switch for earthing switch position) into a unified control circuit architecture. The control unit integrates signals from both micro switches along with auxiliary switch signals to generate comprehensive motor control commands, replacing the need for separate complex control circuits while maintaining precise position indication for both isolator and earthing switch operations

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If auxiliary switches are used for position indication, then device complexity is reduced, but measurement precision deteriorates due to less accurate position signals

Engineering Contradiction:
Improvecontrol circuit complexityVSAvoidposition indication precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent merges auxiliary switch signals with micro switch signals in the control unit. The auxiliary switches provide continuous position information throughout the operation path, while micro switches provide precise discrete position confirmation. The control unit integrates both signal types to achieve both simplicity and precision in motor control

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If electronic memory is used to store current position, then device complexity is reduced, but reliability deteriorates due to potential signal loss during power outages or manual alterations

Engineering Contradiction:
Improvecontrol circuit complexityVSAvoidposition signal reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The control unit continuously monitors and processes real-time signals from micro switches and auxiliary switches during motor operation. This self-service approach eliminates the need for external electronic memory storage, as the system maintains accurate position information through continuous sensor feedback, ensuring reliability even during power outages or manual interventions

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2728600B1Switch assembly for a medium or high voltage switchgear, comprising a three-position switch
Publication Date: 2018.02.21 ABB (SCHWEIZ) AG
  • EP2728600B1 patent drawingFigure 1~2
  • EP2728600B1 patent drawingFigure 3
  • EP2728600B1 patent drawingFigure 4

AI summary

The invention relates to a switch assembly (1) for a medium or high voltage switchgear, comprising a three-position switch (2) with a movable contact piece (3) which can be brought by an electrical motor (4) into three different positions, namely: - a switched-on position (5), which connects the movable contact piece (3) to an isolator contact (6), - an earthing position (7), which connects the movable contact piece (3) to an earth contact (8), and - a disconnected position (9), which is arranged between switched-on position (5) and the earthing position (7), wherein two types of means for generating electrical signals for position indication are arranged at the three-position switch (2), whereof one type is a precise linear operating micro switch (10) generating a discontinuous electrical signal and the other type is a less precise auxiliary switch (11) generating a continuous electrical signal, wherein the electrical signals are transmitted to a control unit (12) for controlling the electrical motor (4), comprising an electrical indication unit (13) for indicating the actual position of the movable contact piece (3), wherein a first micro switch (10a) is coupled to the moving drive of the movable contact piece for detecting the switched-on position (5) and a second micro switch (10b) is coupled to the moving drive of the movable contact piece for detecting the earthing position (7), and two pairs of micro switches (10c, 10d) and auxiliary switches (11a, 11b) are coupled to the moving drive of the movable contact piece for detecting the disconnected position (9), wherein each auxiliary switch (11a, 11b) is both in parallel and/or in series connected to each micro switch (10c, 10d).