Contactor Electromagnet Braking for Carrier Velocity Control

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Solution Overview

Problem

Electromagnetically operated contactors face issues with bouncing effects and high mechanical impact during opening, as existing solutions like rubber dampers are insufficient and costly alternatives like hydraulic dampers are only viable in high-end applications.

Innovation Solution

The method involves using the electromagnet of the contactor as a brake during the opening process, controlled by electronic components and software to manage kinetic energy and prevent back-travel, employing techniques such as re-energizing the coil in a controlled manner to create a braking force that counteracts the movement of the carrier.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If rubber dampers are used to absorb kinetic energy during contactor opening, then some energy absorption (up to 50%) is achieved, but bouncing effects and back travel still occur making the solution insufficient

Engineering Contradiction:
Improvekinetic energy absorptionVSAvoidprevention of back travel
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent replaces the mechanical rubber damper system with an electromagnetic braking system. The electromagnet, already present in the contactor, is repurposed to generate a braking force during opening by controlling the coil current to create a magnetic flux that opposes the armature's motion, thereby eliminating the need for separate mechanical damping components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The electromagnet serves dual functions: it acts as both the actuator for closing the contactor and as a brake during opening. By controlling the coil current direction and magnitude, the same electromagnetic component provides both driving and braking forces, reducing component count and system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If hydraulic dampers or advanced dampers are used to reduce kinetic energy and prevent back travel, then reliable operation is achieved, but the solution becomes costly and only viable in high-end applications

Engineering Contradiction:
Improveprevention of back travelVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The contactor's own electromagnet provides the braking function, making the system self-sufficient. The existing electromagnetic circuit is controlled through software to provide braking without requiring external or additional expensive damping components, thereby reducing manufacturing costs while maintaining reliability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the operational parameters of the electromagnet by controlling the coil current magnitude and direction through software. During opening, the current is adjusted to generate an optimal braking force that prevents back travel, achieving reliable operation through parameter optimization rather than hardware upgrades.

Inventive Principle:
Principle #35Parameter changes

3Speed

If the electromagnet is used as a brake during opening by reversing coil polarity, then velocity reduction is achieved, but additional control complexity is introduced

Engineering Contradiction:
Improvearmature velocity reductionVSAvoidcontrol circuit complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical braking mechanisms with electromagnetic control. By utilizing the existing electromagnet and controlling it through software, the system achieves velocity reduction without introducing additional mechanical components or complex control circuits, thereby minimizing device complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This approach effectively reduces the velocity of the contactor's movement and prevents re-closure, providing a cost-efficient solution to mitigate bouncing effects and ensure reliable operation.

Implementation Method 1

Operation of such contactor entails applying a voltage over the coil, giving a current through it, whereby a magnetic flux is produced in the electromagnet.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The polarity of a power supply for the coil of the contactor is reversed whereby a deceleration is accomplished.

Methodology Applied
Scientific EffectElectromagnetic braking: Electromagnetic Induction

Data Source

PatentEP3069365B1Method for controlling a contactor device, and control unit
Publication Date: 2018.01.10 ABB (SCHWEIZ) AG
  • EP3069365B1 patent drawingFigure 1
  • EP3069365B1 patent drawingFigure 2
  • EP3069365B1 patent drawingFigure 3~4

AI summary

The present disclosure relate to a method 50 performed in a control unit 12 for opening a contactor device 1. The contactor device 1 comprises a carrier 8 being movable between a closed position in which a current is allowed to flow in a current path and an open position in which the current path is broken. The control unit 12 is configured to enable the movement of the carrier 8 between the closed position and the open position by energizing a coil 6 of an electromagnetic circuit. The method 50 comprises: initiating 51 the opening of the contactor device 1 by de-energizing the coil 6, wherein the de-energizing comprises using a demagnetization circuit 40 comprising a discharge element 37, the discharge element 37 being arranged to consume energy in the coil 6; bypassing 52, at a first point of time, the discharge element 37; and re-energizing 53 the coil 6.