Electric Meter Fraud Detection Using Isotropic Ferromagnetic Core Inductance
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Solution Overview
Problem
Existing methods for detecting fraud in electricity consumption measurements, particularly with smart meters, face challenges in reliably detecting magnetic field disturbances and determining the duration of such frauds, as they often rely on Hall effect sensors or resonant circuits that fail to provide comprehensive detection and duration analysis.
Innovation Solution
A method utilizing an electric oscillator with an isotropic ferromagnetic core, whose inductance value changes in the presence of a magnetic field, allowing for the detection of fraud by varying the frequency of an oscillatory electric signal and distinguishing between the start and end of fraudulent activity through threshold comparisons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If Hall effect sensors are used to detect magnetic field disturbances, then detection capability is improved, but detection reliability deteriorates because the presence of an undesirable magnetic source may not be detected depending on the orientation of the magnetic field
Solution Approach 1:
The patent divides the detection function into multiple independent Hall effect sensors arranged in a specific geometric configuration. By segmenting the detection into multiple directional components, the system can reliably detect magnetic fields regardless of their orientation, thus resolving the contradiction between detection capability and reliability.
Solution Approach 2:
The patent transitions from single-axis detection to multi-axis detection by arranging Hall effect sensors in three-dimensional space. This dimensional expansion allows the system to detect magnetic fields from any orientation, eliminating the reliability issue caused by directional limitations.
2Difficulty of detecting and measuring
If resonant circuits with windings are used to detect magnetic fields, then detection capability is improved, but the ability to determine fraud duration deteriorates because the inductance value permanently changes and cannot detect the end of fraud
Solution Approach 1:
The patent replaces the resonant circuit's permanent inductance change with a different physical mechanism that provides temporary, reversible parameter changes. The system monitors parameters that return to baseline when the magnetic field is removed, enabling detection of both the start and end of fraud events.
Solution Approach 2:
The patent substitutes the mechanical/resonant circuit approach with an electromagnetic field-based detection system using Hall effect sensors. This substitution enables the system to detect magnetic field presence without permanent changes, allowing for accurate determination of fraud duration.
3Reliability
If multiple Hall effect sensors are placed to detect magnetic fields from all orientations, then detection reliability is improved, but device complexity increases due to bulk constraints
Solution Approach 1:
The patent segments the detection function across multiple sensors with simplified individual structures, arranged in a coordinated configuration. This segmentation allows each sensor to have a simple design while the collective arrangement achieves comprehensive detection coverage.
Solution Approach 2:
The patent creates a multi-functional sensor arrangement where the same set of sensors performs multiple detection functions simultaneously - detecting magnetic fields from different orientations and providing redundant verification. This universality reduces overall system complexity compared to having separate dedicated sensors for each function.
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 enables accurate detection and duration analysis of fraud, providing a simple and cost-effective means to identify magnetic field disturbances and differentiate between ongoing and new fraudulent activities.
Implementation Method 1
having at least a second inductance value, different from the first inductance value, in the presence in the vicinity of the electric meter of at least one magnetic field capable of modifying a magnetic permeability of the isotropic ferromagnetic core
Implementation Method 2
determining over a first period of time a frequency of an oscillatory electric signal supplied by an electric oscillator included in the fraud detection device and comprising a winding provided with an isotropic ferromagnetic core, said frequency of the oscillatory electric signal depending on the inductance value of the winding provided with the ferromagnetic core
Data Source
AI summary
A method for detecting fraud aimed at disrupting an electricity consumption measurement by an electricity meter by applying a magnetic field in the vicinity of the electricity meter, the method being implemented by a fraud detection device associated with the electricity meter and comprising: a determination (42) over a period of time of a frequency of an oscillatory electrical signal provided by an electrical oscillator included in the fraud detection device and comprising a coil having an isotropic ferromagnetic core, said coil having a first inductance value in the absence of a magnetic field and a second inductance value in the presence of a magnetic field, said frequency of the oscillatory electrical signal depending on the inductance value of said coil;a comparison (44, 47) of the frequency of the determined oscillatory electrical signal with at least one threshold frequency, and a detection (46, 49) of fraud based on a result of the comparison.;