Three-Phase Switching Device with Inverted Control and Compact Footprint

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Solution Overview

Problem

Existing three-phase switching devices in metal enclosures face challenges in achieving independent control of each pole without increasing the device's size or using a large number of parts, while also minimizing mechanical forces and maintaining a small footprint.

Innovation Solution

A three-phase switching device with independent control mechanisms for each pole, where three control devices are arranged above a common metal casing, and the transmission mechanisms have different geometries but identical speed ratios, allowing for identical control device design and reduced mechanical forces during switching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If independent control devices and transmission mechanisms are used for each phase, then independent operation of each pole is achieved, but the device complexity and number of parts increases

Engineering Contradiction:
Improveindependent operation capabilityVSAvoidnumber of parts
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The device is divided into three independent control devices (3R, 3S, 3T), each responsible for one phase. Each control device includes its own transmission mechanism (4R, 4S, 4T) with levers and connecting rods that independently actuate the movable contacts of their respective poles. This segmentation enables independent operation of each pole while maintaining a modular structure that manages complexity through repetition of standardized components.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If three identical metal casings are used for each pole, then independent control is achieved, but the volume and space requirement increases

Engineering Contradiction:
Improveindependent control capabilityVSAvoiddevice volume
Core Design Contradiction:
Adaptability or versatilityVSVolume of stationary object

Solution Approach 1:

Three separate metal casings (one for each pole) are merged into a single common metal casing (2) that houses all three phases. The control devices (3R, 3S, 3T) are positioned above this shared casing, and their transmission mechanisms pass through sealed openings in the casing to reach the movable contacts inside. This merging eliminates the need for three separate casings, reducing overall device volume while maintaining independent control through the separate transmission paths.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If a single mechanical transmission mechanism controls all three phases, then the number of parts is reduced, but independent operation of each pole cannot be achieved

Engineering Contradiction:
Improvenumber of partsVSAvoidindependent operation capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The single transmission mechanism is segmented into three separate transmission mechanisms (4R, 4S, 4T), each dedicated to one phase. Each mechanism includes its own set of levers and connecting rods that independently transmit motion from its control device to the corresponding movable contact. This segmentation provides the necessary independence for each pole to be controlled separately while keeping the overall structure relatively simple through the use of identical modular transmission units.

Inventive Principle:
Principle #1Segmentation

4Area of stationary object

If control devices are arranged below the support structure, then space is utilized, but the footprint and complexity increase

Engineering Contradiction:
Improvespace utilizationVSAvoidarrangement complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

Instead of arranging the control devices (3R, 3S, 3T) below the support structure as in conventional designs, they are inverted and positioned above the common metal casing. This inversion simplifies the overall arrangement by allowing the transmission mechanisms to pass directly through sealed openings in the top of the casing, eliminating the need for complex routing below the structure and reducing the device's footprint.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP2023361B1Three-phase switching device in metal casing with reduced dimensions and phase transmission forces
Publication Date: 2010.06.30 AREVA T&D AG
  • EP2023361B1 patent drawingFigure 1
  • EP2023361B1 patent drawingFigure 2~3
  • EP2023361B1 patent drawingFigure 4

AI summary

The device (1) has a sulfur hexafluoride gas filled metallic casing (2) accommodating three switches i.e. poles (R, S, T), and independent control apparatuses (3R, 3S, 3T) respectively activating movable contacts of the poles. Three mechanical transmission mechanisms (4R, 4S, 4T) are respectively connected to outlet shafts (30R, 30S, 30T) of the apparatuses and the movable contacts, where the apparatuses are placed at exterior and above of the casing. The mechanisms have different geometries and identical speed ratios irrespective of transmission instants during switching.