Current Sensor Shielding for Noise Suppression
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Solution Overview
Problem
Current current sensors face challenges in accurately detecting measurement currents due to electromagnetic noise interference, which can lead to magnetic saturation and leakage, affecting the precision of current measurements.
Innovation Solution
A current sensor design incorporating an electrical-conduction member, a magnetoelectric converter, and a shield with a unique configuration of first and second shields, where the electrical-conduction member and magnetoelectric converter are positioned between the shields, with the shields' center parts having greater lengths than their end parts, reducing electromagnetic noise permeation and magnetic saturation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional current sensor is used, then current detection is performed, but electromagnetic noise causes magnetic saturation and leakage, reducing measurement precision
Solution Approach 1:
A shield member is introduced as an intermediary component between the measurement current path and the detection circuit. This shield member, having high magnetic permeability, acts as a mediator that preferentially conducts magnetic flux through itself rather than allowing it to reach the detection circuit, thereby protecting the measurement system from electromagnetic noise
Solution Approach 2:
The shield member utilizes the harmful electromagnetic noise (unwanted magnetic flux) and redirects it through a controlled path. By providing a low-reluctance path through the shield member, the unwanted magnetic flux is converted from a harmful interference into a controlled magnetic flow that does not affect the measurement accuracy
2Measurement precision
If shielding components are added to suppress electromagnetic noise, then measurement precision improves, but device complexity increases
Solution Approach 1:
The shield member serves multiple functions simultaneously: it acts as electromagnetic shielding, provides structural support for the measurement current path, and guides magnetic flux. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while maintaining improved measurement precision
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 effectively suppresses electromagnetic noise leakage, enhancing the accuracy of current detection by minimizing magnetic saturation and noise interference, thereby improving the overall precision of measurement current detection.
Implementation Method 1
The shield includes a first shield and a second shield each having a plate shape, and the first shield and the second shield are arranged such that surfaces are opposed to and spaced away from each other
Implementation Method 2
The magnetoelectric converter converts a measurement magnetic field caused by a flow of the measurement current into an electric signal
Data Source
AI summary
A current sensor includes an electrical-conduction member, a magnetoelectric converter and a shield. The shield includes a first shield and a second shield arranged such that surfaces are opposed to and spaced away from each other. A part of the electrical-conduction member and the magnetoelectric converter are located between the first shield and the second shield. The part of the electrical-conduction member located between the first and second shields extends in an extension direction that is along the surface of the first shield. In at least one of the first shield and the second shield, a center part has a length greater than lengths of opposite end parts in a lateral direction that is along the surface of the first shield and perpendicular to the extension direction. The magnetoelectric converter is located between the opposite end parts of the first and second shields in the extension direction.