Non-Intrusive Current Sensor for Compact Protection Devices
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Solution Overview
Problem
Existing electrical protection devices with integrated energy measuring devices require intrusive current and voltage measurement, which limits their integration in compact spaces and imposes constraints on terminal access and connections.
Innovation Solution
A non-intrusive current and voltage measuring device with a U-shaped magnetic core and secondary coils placed around air gaps, integrated in a compact design that fits within the width of standard electrical protection devices, allowing for precise measurement without direct access to electrical wires, using magnetic U's made of FeSi or FeNi and nanocrystalline materials to minimize external field influence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If intrusive measurement means are integrated inside the protection device, then measurement function is achieved, but device width increases and terminal access is constrained
Solution Approach 1:
The current measurement function is extracted from the protection device by using an external current sensor with a magnetic core that clamps around the conductor outside the device. This removes the need for intrusive internal measurement components, maintaining measurement accuracy while reducing device width and preserving terminal access.
2Measurement precision
If intrusive measurement means are integrated inside the protection device, then measurement function is achieved, but terminal access and connections are constrained
Solution Approach 1:
The measurement function is extracted to an external sensor that clamps around the conductor without interfering with terminal access. The sensor operates independently outside the device, allowing terminals to remain fully accessible for wiring operations while maintaining accurate current measurement.
3Volume of moving object
If compact design is used to fit within standard protection device width, then device integration is improved, but measurement accuracy may be compromised
Solution Approach 1:
An external current sensor serves as an intermediary measurement device that provides accurate current data without requiring integration within the compact protection device. The sensor's magnetic core clamps around the conductor and delivers measurement signals to the protection device, enabling accurate measurement while maintaining the standard device width.
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
Enables precise, non-intrusive measurement of current and voltage within a compact form factor, meeting class 2 measurement accuracy objectives, and allows for flexible integration with existing protection devices without modifying the electrical installation, while minimizing external magnetic field interference.
Implementation Method 1
a secondary measurement coil being placed around each of the two air gaps, said coils being connected in series and delivering a signal representative of the current flowing in the device
Implementation Method 2
the aforementioned magnetic core comprises two U's separated by two air gaps
Data Source
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AI summary
The device (D) has a set of pass-through holes forming terminals (2) delineated by a part made of an insulating material. The terminals pass through a set of conductors. The conductors are designed to be electrically connected via one of its ends to respective contact strips of the terminals. A magnetic core (8) partially surrounds the terminals and comprises an air gap around which secondary coils are wound between end portions of the air gap. The coils deliver a signal representative of current flowing through the device.