Contactor Coil Control With Dual Magnetic Units and Freewheel Current

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Solution Overview

Problem

Conventional contactor designs face high power consumption and short service life due to inefficient coil control solutions, which also complicate diagnostic functions and have long verification cycles.

Innovation Solution

A control device for contactors that utilizes dual magnetic units and control units to manage inrush and holding phases, reducing energy consumption by optimizing current flow through freewheel loops and voltage stabilization, thereby minimizing power usage and extending the contactor's operational life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional flyback circuit-based coil control solution or low side coil control solution is employed, then the contactor can control the load, but the power consumption is large causing rapid temperature rise and shortened service life

Engineering Contradiction:
Improveservice lifeVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The control device segments the coil control into two distinct phases: inrush phase (using first magnetic unit and first control units) and holding phase (using second magnetic unit and second control units). This segmentation allows optimized control strategies for each phase, reducing overall power consumption while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control device implements periodic switching between inrush phase and holding phase through the controller. During inrush phase, full power is applied to close contacts; during holding phase, reduced power is sufficient to maintain contact closure. This periodic action significantly reduces average power consumption and temperature rise.

Inventive Principle:
Principle #19Periodic action

2Ease of operation

If conventional coil control solutions are used, then the contactor can operate, but the design is difficult and verification cycle is long making diagnostic function difficult to achieve

Engineering Contradiction:
Improvediagnostic capabilityVSAvoiddesign complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The control device incorporates current monitors that provide feedback on coil current during both inrush and holding phases. This feedback enables the controller to adjust control signals in real-time and provides diagnostic information about contactor operation, simplifying troubleshooting and reducing verification cycles.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The controller acts as an intermediary between the power source and the magnetic units, implementing intelligent control logic that simplifies the overall system design. The controller manages the complex switching between inrush and holding phases, while providing standardized control interfaces and diagnostic outputs that ease operation and maintenance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution reduces energy consumption and prolongs the service life of contactors while enabling efficient diagnostic capabilities through optimized current management and reduced power draw.

Implementation Method 1

by allowing an electrical current to flow through a coil to generate a magnetic field

Methodology Applied
Scientific EffectMagnetic field generation: Electromagnet

Implementation Method 2

the freewheel unit is connected to the first magnetic unit and the second magnetic unit

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4080537B1Control device and method for contactor
Publication Date: 2025.10.15 SCHNEIDER ELECTRIC IND SAS
  • EP4080537B1 patent drawingFigure 1
  • EP4080537B1 patent drawingFigure 2
  • EP4080537B1 patent drawingFigure 3

AI summary

Embodiments of the present disclosure relate to a control device and method for a contactor. The control device comprises a first high-side control unit, a second high-side control unit, a first low-side control unit and a second low-side control unit. The first high-side control unit and the second high-side control unit respectively connect a first magnetic unit and a second magnetic unit of the contactor to a power supply. The first low-side control unit is connected between the first magnetic unit and a reference voltage node, and the second low-side control unit is connected between the second magnetic unit and the reference voltage node. The control device further comprises a freewheel unit connected to the first magnetic unit and the second magnetic unit. The control device further comprises a controller. The controller is used to control operations of the control units so that in a state that at least one magnetic unit of the first magnetic unit and the second magnetic unit is disconnected from the power supply, a current of the at least one magnetic unit flows through the freewheel unit. According to embodiments of the present disclosure, the contactor may be made more energy-saving, and the operation cost may be reduced.