Multi-Hall Electricity Meter Metrology Without Magnetic Concentrator
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Solution Overview
Problem
Traditional Hall-based metrology devices in electricity meters are susceptible to tampering through DC magnet attacks, leading to reduced measurement accuracy and potential under-billing, and are also affected by external AC fields and cross-talk between phases.
Innovation Solution
A multi-Hall effect device configuration is used without a magnetic concentrator, employing a substrate to support Hall effect devices on both sides of electrical conductors, which eliminates the need for an iron core, reduces external AC field interference, and minimizes cross-talk, while allowing for automated manufacturing and assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic concentrator (iron core) is used in traditional Hall-based metrology devices, then the magnetic field is strengthened and concentrated, but the device becomes susceptible to DC magnet attacks that saturate the core and degrade measurement accuracy
Solution Approach 1:
The patent removes the magnetic concentrator (iron core) from the Hall-based metrology device, extracting the vulnerable component that enables DC magnet attacks. By eliminating the ferromagnetic material, the system no longer has a core that can be saturated by external DC magnets, thereby preventing tampering while maintaining measurement capability through direct Hall effect sensing of the magnetic field generated by current in the conductor.
Solution Approach 2:
The patent introduces a non-magnetic support structure or mounting mechanism as an intermediary to position the Hall effect sensor relative to the current-carrying conductor without using a magnetic concentrator. This intermediary allows the sensor to detect the magnetic field generated by the conductor current while preventing direct magnetic coupling that would require a ferromagnetic core, thus eliminating the vulnerability to DC magnet saturation attacks.
2Measurement precision
If a magnetic concentrator is used to strengthen the magnetic field, then measurement sensitivity is improved, but external AC fields and cross-talk between phases interfere with measurements
Solution Approach 1:
The patent extracts and eliminates the magnetic concentrator that amplifies both the desired magnetic field from the conductor and the harmful external AC fields. By removing the ferromagnetic material, the system reduces magnetic coupling with external sources and minimizes cross-talk between phases, while still maintaining sufficient measurement sensitivity through the direct Hall effect detection of the conductor's magnetic field without core amplification.
3Measurement precision
If a magnetic concentrator is used in the metrology device, then the Hall effect device can detect the magnetic field, but the device complexity increases due to the need for iron core and shielding
Solution Approach 1:
The patent removes the magnetic concentrator, shielding materials, and associated complex structural elements from the metrology device. By extracting these components, the design simplifies to a more straightforward configuration where the Hall effect sensor is positioned in close proximity to the current-carrying conductor, detecting the magnetic field directly without requiring ferromagnetic cores or complex magnetic shielding structures.
Solution Approach 2:
The patent replaces the mechanical/magnetic system involving iron cores and magnetic concentrators with a direct electronic sensing approach. The Hall effect sensor electronically detects the magnetic field generated by the conductor current without requiring physical magnetic coupling through ferromagnetic materials, thereby simplifying the mechanical structure and reducing the need for complex magnetic circuit design.
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 configuration enhances measurement accuracy by preventing DC magnet attacks, reducing the impact of external AC fields, and minimizing cross-talk, thereby improving the reliability and precision of electricity meter readings.
Implementation Method 1
metrology devices that use Hall effect devices ('Hall-based' metrology devices) leverage the Hall effect to allow the metrology device to detect an electric current flowing through one or more electrical conductors. That is, an electrical conductor with a current flowing through it produces a magnetic field that is proportional to the current flowing through the electrical conductor. This magnetic field is detectable by the Hall effect device which generates an output corresponding to the magnetic flux density of the magnetic field.
Data Source
AI summary
Disclosed is a metrology assembly that utilizes a multi-Hall effect device configuration which eliminates the necessity of a magnetic concentrator. In some embodiments, the metrology assembly includes a substrate or support platform configured to support at least two Hall effect devices per phase of an electricity meter. The metrology assembly may further include one or more electrical conductors coupled to the substrate and configured to conduct electric current. The at least two Hall effect devices may be coupled to the substrate at opposing sides of an associated electrical conductor, each Hall effect device being configured to detect a magnetic field created by the electric current of the associated electrical conductor, and to generate an output.