Current Sensing With Magnetic Crosstalk Compensation
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Solution Overview
Problem
Current sensing systems are affected by crosstalk from neighboring conductors, leading to inaccurate current measurements, which is difficult to mitigate without increasing physical separation or incurring high computational costs.
Innovation Solution
A current sensor with integrated magnetic sensing elements measures magnetic field parameters in multiple directions, using a weight coefficient to compensate for crosstalk based on the geometry and position of conductors, allowing for compact designs without additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If physical separation between conductors is increased to reduce crosstalk, then measurement precision is improved, but device compactness deteriorates
Solution Approach 1:
The patent introduces an intermediary mathematical model (crosstalk compensation matrix) that mediates between the magnetic field measurements and the actual current values. This matrix, derived from the geometric relationships between conductors and sensor, allows the system to subtract crosstalk contributions from the measured magnetic field, thereby achieving accurate current measurement without physical separation of conductors.
Solution Approach 2:
The patent changes the measurement approach by moving from direct current measurement to magnetic field measurement, and further to processed current measurement through parameter transformation. By measuring magnetic field components in multiple directions and applying geometric parameter relationships, the system transforms the raw measurement into an accurate current value while maintaining compact device layout.
2Measurement precision
If crosstalk compensation is performed using microcontroller calculations, then measurement precision is improved, but computational complexity and cost increase
Solution Approach 1:
The patent performs preliminary action by pre-calculating and storing the crosstalk compensation matrix and geometric parameters in the microcontroller before actual measurement. This allows the complex compensation calculations to be performed using simple matrix multiplication during operation, significantly reducing real-time computational complexity while maintaining measurement precision.
Solution Approach 2:
The patent creates a mathematical copy of the physical geometric relationships between conductors and sensor. Instead of physically separating conductors or using complex real-time calculations, the system uses a pre-computed mathematical model that replicates the geometric effects, allowing simple matrix operations to achieve accurate current measurement.
3Measurement precision
If multiple magnetic sensors are used to reduce crosstalk, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent makes the single magnetic sensor universal by enabling it to perform multiple measurement functions through multi-directional sensing. The sensor measures magnetic field components in different directions (e.g., vertical and horizontal components), and the processor uses these multi-functional measurements to separately determine current values for multiple conductors, eliminating the need for additional sensors.
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
Accurate current measurement is achieved with reduced crosstalk, enabling stable and efficient current monitoring in compact devices with simplified processor programming and calibration.
Implementation Method 1
a magnetic sensor for sensing a component of a magnetic field at two different locations and determining a current based on a weighted difference of the two measured values
Implementation Method 2
the at least one magnetic sensor comprises a Hall effect sensor
Data Source
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Figure 3
Figure 4~7
AI summary
A current sensor is provided for a target conductor, of a plurality of conductors. It includes at least one magnetic sensor configured to provide two signals representative of two different parameters of the field or a gradient thereof. It also includes a processor configured for deriving a signal indicative of the current based on a linear combination of the first signal and the at least second signal. At least one of these signals is weighted by a coefficient, being a constant chosen in accordance with a distance, in at least the first or second direction, between the sensor and at least one conductor of the plurality. The coefficient is chosen so as to reduce a contribution of a parasitic magnetic field in the signal indicative of the current in the first conductor, where the parasitic magnetic field is generated by at least a further conductor.