Electromagnet Reset Assembly for Faster Transfer Switch Reclosing

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Solution Overview

Problem

Existing electromagnet driving mechanisms in three-station dual power automatic transfer switches face challenges in quickly resetting the movable core to the initial position due to residual electromagnetic force, failing to meet transfer time requirements.

Innovation Solution

An electromagnet driving mechanism with a reset auxiliary assembly that includes a push member and a reset auxiliary spring, interacting with the movable core during the approaching stroke section to provide an additional reset spring force, facilitating quick reset of the movable core.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the electromagnet drive mechanism uses residual electromagnetic force to reset the movable core, then the structure is simple and power consumption is low, but the reset time is too long to meet transfer time requirements

Engineering Contradiction:
Improvereset timeVSAvoidstructure complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The reset process is segmented into two phases: initial reset phase using residual electromagnetic force, and accelerated reset phase using the reset auxiliary spring when the movable core enters the approaching stroke section. This segmentation allows the system to use simple residual force for most of the reset journey, then apply additional force only when needed for the final acceleration phase.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reset auxiliary spring is pre-compressed during the approach stroke section, storing elastic potential energy in advance. When the movable core enters the approaching stroke section, the pre-compressed spring immediately releases its stored energy to accelerate the reset process, eliminating the need for complex real-time control systems.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the electromagnet drive mechanism drives twice successively with larger volume and power consumption, then the transfer reliability is improved, but the volume and power consumption increase

Engineering Contradiction:
Improvetransfer reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The reset auxiliary spring converts the potentially harmful residual electromagnetic force (which prevents quick reset) into a beneficial element by using the approach stroke section as a trigger mechanism. The spring remains dormant during normal operation and only activates when the movable core enters the approaching stroke section, turning the residual force problem into a timing mechanism for accelerated reset.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Speed

If the electromagnet drive mechanism uses only residual electromagnetic force for reset, then the structure is simple, but the reset speed is insufficient

Engineering Contradiction:
Improvereset speedVSAvoidstructure complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The reset mechanism transitions from a static residual electromagnetic force system to a dynamic system that adapts its force output based on the movable core's position. The reset auxiliary spring dynamically engages only when the movable core enters the approaching stroke section, providing variable force assistance that maximizes reset speed while minimizing structural complexity.

Inventive Principle:
Principle #15Dynamics

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 reset auxiliary assembly significantly reduces the reset time of the movable core by over 50%, ensuring rapid transition between power supplies without affecting normal operation.

Implementation Method 1

a coil, coupled with the stationary core and/or the movable core, wherein the coil generates a magnetic attraction force between the stationary core and the movable core upon being energized

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a reset auxiliary spring connected with the push member, wherein the reset auxiliary assembly is configured to interact with the movable core in the approaching stroke section, so that the reset auxiliary spring applies a reset auxiliary spring force to the movable core

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4207227B1Electromagnet driving mechanism, assembly and dual power automatic transfer switch
Publication Date: 2026.05.06 SCHNEIDER ELECTRIC IND SAS
  • EP4207227B1 patent drawingFigure 1~2A
  • EP4207227B1 patent drawingFigure 2B
  • EP4207227B1 patent drawingFigure 3A~3B

AI summary

Disclosed are an electromagnet driving mechanism 100, an electromagnet driving assembly and a dual power automatic transfer switch. The electromagnet driving mechanism comprises: a mechanism frame 140; a stationary core 130; a movable core 120, including a moving stroke between a first position away from the stationary core and a second position in contact with the stationary core, the moving stroke including an approaching stroke section; a coil, configured to generate a magnetic attraction force between the stationary core and the movable core upon being energized to drive the movable core to move towards the second position; a reset spring member 112; and a reset auxiliary assembly 150, including a push member 152 and a reset auxiliary spring 154. The reset auxiliary assembly applies a reset auxiliary spring force to the movable core in the approaching stroke section through the push member. The dual power automatic transfer switch includes: an electromagnet driving mechanism assembly; a first stationary contact and a second stationary contact; a movable contact; the electromagnet driving mechanism assembly drives the movable contact to move among a first contact position, a double-separation position and a second contact position.