Current Sensor Magnetic Saturation Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional current sensors face measurement errors and reduced accuracy when measuring high currents due to magnetic field saturation, and they have low sensitivity for low currents due to narrow linear measurement regions.
Innovation Solution
A current sensor design that includes a primary conductor, magnetic sensors to detect the magnetic field, and a magnetic body with a plate extending along the detection axis, where the magnetic body is magnetically saturated to correct the output voltage and maintain sensitivity across a broader measurement range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional magnetic sensor is used to measure high current, then the measurement range is extended, but the measurement accuracy deteriorates due to magnetic field saturation
Solution Approach 1:
The magnetic body is divided into multiple segments along the detection axis, with each segment having different magnetization characteristics. This segmentation allows different portions of the magnetic path to handle different current ranges, enabling the sensor to maintain accuracy across a broader measurement range by preventing saturation in critical measurement regions
Solution Approach 2:
Different regions of the magnetic body are given different magnetic properties - some regions are designed to saturate at high currents while others maintain linearity for low current measurements. This local differentiation of magnetic characteristics allows the sensor to simultaneously achieve high measurement range and maintain precision across the entire range
2Measurement precision
If a magnetic sensor with wide linear region is used, then measurement accuracy for high current is improved, but sensitivity for low current deteriorates
Solution Approach 1:
The magnetic body incorporates regions with different magnetization characteristics along the detection axis. Regions closer to the primary conductor maintain high permeability for sensitivity, while distant regions are designed to saturate at appropriate thresholds, creating a cascaded response that preserves both sensitivity and accuracy across different current magnitudes
Solution Approach 2:
The magnetic body's effective permeability dynamically changes with current magnitude due to the progressive saturation of different segments. At low currents, all segments contribute with high permeability for maximum sensitivity. As current increases, segments progressively saturate, dynamically adjusting the overall magnetic response to maintain linearity and accuracy across the full measurement range
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
The design allows for accurate measurement of high currents while maintaining sensitivity for low currents, expanding the measurement range and reducing output errors.
Implementation Method 1
at least one magnetic sensor that detects a strength of a magnetic field produced by the current flowing in the primary conductor
Implementation Method 2
magnetization characteristics of the magnetic body include a magnetic saturation region in which permeability decreases in ranges where an absolute value of the current is no less than a threshold
Data Source
AI summary
A current sensor includes a primary conductor in which a current flows, a magnetic sensor that detects a strength of a magnetic field produced by the current, and a magnetic body that surrounds a periphery of the primary conductor and the magnetic sensor. Output characteristics of the magnetic sensor include a low-output region in which a measured voltage value lower than a virtual output voltage proportional to a value of the current is outputted. Magnetization characteristics of the magnetic body include a magnetic saturation region in which permeability decreases in ranges where an absolute value of the current is no less than a threshold. An output of the magnetic sensor is corrected such that the measured voltage value increases as a result of a magnetic field leaking from the magnetic body that is within the magnetic saturation region acting on the magnetic sensor that is in the low-output region.