Non-Contact Electrical Measurement With Radial Dual Sensors
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Solution Overview
Problem
Conventional electrical parameter measurement devices require galvanic contact, posing safety risks and limitations in current measurement capacity, and existing non-contact devices lack accuracy in measuring voltage magnitude and are prone to positional errors.
Innovation Solution
A non-contact electrical parameter measurement device using radially mounted magnetic field sensors and control circuitry to determine conductor position and measure current and voltage without galvanic contact, employing dual sets of sensors for compensation and calibration to enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional voltmeters use galvanic contact with conductors, then voltage measurement is achieved, but safety risks increase and insulation must be cut away
Solution Approach 1:
The patent replaces the mechanical galvanic contact system with a non-contact electromagnetic sensing system. The voltage sensor detects AC voltage through electromagnetic coupling with the conductor without physical contact, eliminating the need to cut insulation or expose wires while maintaining measurement capability.
2Measurement precision
If general purpose multimeter uses internal current shunt, then current measurement is achieved, but maximum current is limited to ten amperes
Solution Approach 1:
The patent replaces the internal current shunt system with a non-contact current clamp system. The current clamp senses the magnetic field generated by current flow in the conductor without requiring the conductor to pass through the multimeter or break the circuit, enabling measurement of much higher current levels beyond the 10-ampere limit of shunt-based systems.
3Measurement precision
If clamp-on multimeter uses magnetic core, then current measurement capability is improved, but device weight increases due to substantial iron
Solution Approach 1:
The patent extracts and removes the substantial iron magnetic core from the current clamp assembly. By eliminating this heavy component while retaining the magnetic field sensing capability through alternative means, the device weight is significantly reduced while maintaining current measurement functionality.
4Device complexity
If single set of magnetic field sensors is used, then device complexity is reduced, but measurement accuracy decreases due to positional errors
Solution Approach 1:
The patent divides the sensing system into multiple discrete magnetic field sensors positioned at different radial locations around the conductor. This segmentation allows the system to detect magnetic field variations from different positions and use signal processing to compensate for conductor positioning errors, thereby improving measurement accuracy without excessive complexity increase.
5Adaptability or versatility
If high current flows through conductor, then measurement range is extended, but magnetic core saturation occurs
Solution Approach 1:
The patent removes the magnetic core entirely from the sensing system. By using coreless magnetic field sensors that directly detect the magnetic field generated by current flow, the system eliminates magnetic saturation effects that limit measurement range in core-based designs, enabling accurate measurement of high current levels.
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 safe, high-accuracy measurement of AC and DC currents and voltages with reduced positional errors and saturation issues, offering improved performance and cost-effectiveness compared to conventional methods.
Implementation Method 1
The current clamp is closed around the current-carrying conductor to sense the magnetic field created by the current flow
Implementation Method 2
a first set of magnetic field sensors positioned at a first radial distance from a center of the opening, and a second set of magnetic field sensors positioned at a second radial distance from the center of the opening
Data Source
Figure 1
Figure 2~3
Figure 4~5B
AI summary
Systems and methods for operating and calibrating electrical parameter measurement devices are provided herein. The devices may include a current sensor that includes a plurality of magnetic field sensors positioned around a measurement area that receive a current carrying conductor under test. The sensor may include a plurality of concentric rings of magnetic field sensors that provide accurate measurements that ignore magnetic fields from conductors or other components outside of the measurement area. The sensors may be used to determine the position of a conductor under test, and such information may be used to produce accurate measurements by accounting for the conductor's position. A calibration system may also be provided that is operative to generate calibration data that is subsequently used to provide more accurate measurements. The calibration data may include one or more lookup tables, coefficients for one or more mathematical formulas, or other types of data.