Current Sensing Device Environmental Magnetic Field Filtering
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Solution Overview
Problem
Conventional non-contact current measurement devices lack accuracy due to variations in installation position and the presence of environmental magnetic fields, which are not filtered out, leading to inaccurate current calculations.
Innovation Solution
A current sensing device comprising a magnetic sensor, a signal receiving unit, and a microprocessor with an environmental magnetic field filtering unit and an effective current calculation unit, which filters out environmental magnetic fields from the sensing signal to accurately calculate the current flowing in an electrical cable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple magnetic sensors are used to sense current in electrical cables, then the device can measure electrical characteristics including current, but the measurement accuracy varies due to installation position changes and environmental magnetic fields
Solution Approach 1:
The patent extracts and removes the environmental magnetic field component from the total magnetic field signal detected by the magnetic sensor. By separating the useful current-induced magnetic field from the harmful environmental magnetic field interference, the system achieves accurate current measurement regardless of installation position or environmental conditions.
Solution Approach 2:
The system uses feedback by measuring the magnetic field at different positions and using the difference to calculate and eliminate environmental magnetic field interference. The microprocessor continuously adjusts the measurement by comparing signals from different sensor positions and compensating for environmental factors.
2Adaptability or versatility
If the housing is positioned at different distances from the electrical cable, then the device can be installed flexibly, but the magnetic field strength detected by the sensor changes according to Biot-Savart law, affecting measurement accuracy
Solution Approach 1:
The system dynamically adjusts measurements by detecting magnetic field strength at multiple positions and using the variation in signal strength to calculate and eliminate environmental magnetic field effects. This allows flexible installation at any position while maintaining measurement accuracy through dynamic compensation.
Solution Approach 2:
The patent changes the measurement parameters by taking measurements at different positions and using the parameter variations to distinguish between current-induced magnetic field and environmental magnetic field, thereby maintaining accuracy across different installation positions.
3Device complexity
If environmental magnetic fields are not filtered, then the device structure remains simple, but the measurement accuracy is compromised by noise magnetic fields
Solution Approach 1:
The patent introduces an intermediary computational process that acts as a virtual filter. Instead of using physical filtering components, the system uses mathematical calculations and signal processing to eliminate environmental magnetic field effects, achieving accurate measurement without adding complex physical filtering hardware.
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 solution achieves high accuracy in current measurement with a ±5% error margin, improving the stability and reliability of current sensing data compared to conventional methods.
Implementation Method 1
at least one magnetic sensor, being located at an initial sensing position for being spaced apart from an electrical cable by a sensing distance, so as to sensing a first induced magnetic field from the electrical cable
Implementation Method 2
the magnetic field induced by the straight conductor can be calculated by using Biot-Savart law
Data Source
AI summary
Disclosures of the present invention describe a current sensing device and method, wherein the current sensing device comprises: at least one magnetic sensor, a signal receiving unit and a microprocessor. Particularly, the present invention provides an environmental magnetic field filtering unit and an effective current calculation unit in the microprocessor, such that the microprocessor is able to calculate the value of a current flowing in a specific electrical cable with high accuracy based on a sensing magnetic field outputted from the magnetic sensor.