Inductive Transformer for Electromagnetic Drive Parameter Measurement

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Solution Overview

Problem

Existing electromagnetic drive systems for switching devices require complex circuits with additional components, leading to increased production costs and potential electromagnetic compatibility (EMC) issues, especially when using multiple coils.

Innovation Solution

A switching device with an inductive transmitter connected in series with a coil, allowing direct measurement of electromagnetic drive variables using a digital electronic measuring device without a complex resonant circuit, reducing the need for additional components and minimizing EMC interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a resonant circuit with additional coils and capacitors is used to measure coil inductance, then measurement capability is achieved, but device complexity and electromagnetic compatibility issues increase

Engineering Contradiction:
Improvecoil inductance measurementVSAvoidcircuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the measurement function from a complex resonant circuit and implements it using a simple series connection of an existing coil with a measuring device. The coil's inductance is measured by detecting voltage changes across it during switching operations, eliminating the need for separate resonant circuit components while maintaining measurement capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The coil serves dual functions: it acts as both the electromagnetic actuator and the measured component. By monitoring the voltage across the coil during its normal switching cycles, the system performs measurement without requiring separate dedicated measurement hardware, thus reducing overall device complexity

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

2Manufacturing precision

If multiple coils (pull-in and holding) are used in electromagnetic drive, then control precision is improved, but production costs and potential error sources increase

Engineering Contradiction:
Improveswitching control precisionVSAvoidproduction cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent combines the control functions of pull-in and holding coils into a single coil system. By implementing precise current control algorithms that manage the single coil's switching characteristics, the system achieves the same level of switching control precision while eliminating the need for separate pull-in and holding coils, thereby reducing production costs and potential error sources

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If additional measuring components and resonant circuits are added, then measurement accuracy is achieved, but electromagnetic compatibility is worsened

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidelectromagnetic compatibility
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent converts the naturally occurring voltage changes during coil switching into useful measurement signals. By monitoring the inherent voltage across the coil during its normal operation, the system achieves measurement accuracy without adding external signal sources that could cause electromagnetic interference, thus maintaining good electromagnetic compatibility

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

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 solution simplifies the circuit, reduces production costs, and minimizes EMC issues, enabling efficient measurement of variables like current, temperature, and inductance in single-coil or multi-coil electromagnetic drives, while maintaining accurate control and monitoring of the drive's mechanical state.

Implementation Method 1

an inductive transformer, the primary side (12) of which is connected in series with a coil (14) of the electromagnetic drive (100)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2884233B1Measuring of parameters in an electromagnetic drive of a switching device
Publication Date: 2021.09.01 EATON INTELLIGENT POWER LTD
  • EP2884233B1 patent drawingFigure 1
  • EP2884233B1 patent drawingFigure 2
  • EP2884233B1 patent drawingFigure 3

AI summary

The invention relates to a device for measuring quantities in the electromagnetic drive of a switching device, in particular a contactor, a control device and a regulating device with such a measuring quantity device, and switching devices with such a control or regulating device. One embodiment of the invention relates to a device for measuring quantities in the electromagnetic drive of a switching device with an inductive transformer (10) whose primary side (12) is connected in series with a coil (14) of the electromagnetic drive, and a digital electronic measuring device (18) connected to the secondary side (16) of the transformer for measuring a voltage UL2 transmitted to the secondary side and for determining at least one measured quantity of the electromagnetic drive depending on the measured voltage UL2 and known values ​​of the system according to at least one determination and calculation function.