Fluxgate Current Transducer Dual-Path Error Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional fluxgate current transducers may produce inaccurate or faulty measurement signals, leading to potential system malfunctions, and existing redundant systems are costly, space-consuming, and increase the risk of failure.

Innovation Solution

A fluxgate-based current transducer with two independent measurement signal paths, one generating a pulse width modulated signal and the other an analog signal, which are processed in real-time to detect errors and ensure accurate measurement, using a signal processing unit to compare differences and generate an error signal if tolerance is exceeded.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a second redundant current transducer is installed to detect malfunctions, then reliability is improved, but device complexity, cost, space consumption, and power consumption increase

Engineering Contradiction:
Improvedetection of malfunctionVSAvoidnumber of transducers
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The single transducer is segmented into two independent measurement signal paths (first path P1 and second path P2) that process signals separately. Each path has its own measurement circuit portion, allowing independent operation and comparison without requiring a second physical transducer device.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Two measurement signal paths are merged within a single transducer device, combining the functionality of what would traditionally require two separate transducers. The signal processing unit integrates both paths and compares their outputs, achieving redundancy and fault detection in one unified device.

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If conventional single transducer systems are used, then device complexity and cost are reduced, but the ability to detect faulty measurements is insufficient

Engineering Contradiction:
Improvenumber of transducersVSAvoiddetection of faulty measurement
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The signal processing unit implements continuous feedback by comparing the first measurement signal S1 from path P1 with the second measurement signal S2 from path P2. When the difference exceeds a tolerance threshold, an error signal is generated, providing real-time feedback on transducer health and measurement validity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The dual measurement signal paths perform preliminary measurements and comparisons before final output is generated. This preliminary action allows the system to detect errors before they propagate to the final measurement output, enabling preventive error detection.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If rapid detection of faulty measurements is implemented, then system safety is improved, but response time and processing complexity increase

Engineering Contradiction:
Improverapid detection of errorVSAvoiddetection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The comparison between measurement signals S1 and S2 is performed continuously in real-time by the signal processing unit, without interruption or delay. This continuous action ensures that errors are detected immediately when they occur, minimizing detection time and enabling rapid system response.

Inventive Principle:
Principle #20Continuity of useful action

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 provides accurate and reliable current measurements, detects faulty transducer outputs effectively, reduces costs, and minimizes the risk of system failures by comparing independent measurement signals, ensuring timely correction and maintaining system performance and safety.

Implementation Method 1

a fluxgate magnetic field detector (4)... the fluxgate magnetic field detector comprises a saturable core made of a soft magnetic material and an excitation coil (14)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The excitation coil is driven by an oscillating current of a measuring circuit that is configured to alternatingly saturate the saturable core

Methodology Applied
Scientific EffectMagnetic saturation: Magnetic Saturation

Data Source

PatentEP3526614B1Electrical current transducer
Publication Date: 2022.01.05 LEM INT SA
  • EP3526614B1 patent drawingFigure 1~3
  • EP3526614B1 patent drawingFigure 4
  • EP3526614B1 patent drawingFigure 5a~5b

AI summary

Fluxgate based current transducer (2) for measuring a primary current flowing in a primary conductor, comprising a fluxgate magnetic field detector (4) and a measuring circuit (6). The fluxgate magnetic field detector (4) includes an excitation coil (14) driven by an oscillating excitation current (I fluxgate) supplied by the measuring circuit (6). The measuring circuit (6) is configured to provide a first and a second measurement output of the oscillating excitation current. The transducer (2) further comprises a signal output processing unit (7) for comparing in real-time the first and second measurements outputs, wherein the signal output processing unit (7) is configured to send an error signal output if the difference between said first and second measurements outputs exceeds a tolerance value.