Rogowski Coil Current Sensor with Dielectric and Faraday Shielding
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Solution Overview
Problem
Existing current sensor devices in utility meters, such as Rogowski coils, face accuracy issues at low and high current conditions and require multiple calibration processes, increasing manufacturing time and cost.
Innovation Solution
A sensor device with a substrate of bobbins and a coil having a dielectric material positioned between the coil and conductor to reduce capacitance, along with Faraday shields to enhance accuracy and reject electromagnetic interference, allowing for single calibration across a range of voltages and currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If Rogowski coils are used for current sensing, then the device size is reduced compared to transformer sensors, but measurement precision deteriorates at low and high current conditions
Solution Approach 1:
The patent introduces a dielectric material between the Rogowski coil and conductor to modify the electrical parameters of the sensing system. This dielectric material optimizes the capacitance and inductance characteristics, enabling the coil to maintain accurate measurements across both low and high current conditions while preserving the compact size advantage of Rogowski coils.
2Measurement precision
If multiple calibration processes are applied to Rogowski coils, then measurement precision improves, but productivity decreases due to increased manufacturing time
Solution Approach 1:
The dielectric material is pre-installed between the Rogowski coil and conductor during the manufacturing process, before calibration. This preliminary structural configuration ensures that the electrical parameters are optimized from the outset, allowing the sensor to achieve high measurement precision with minimal or single calibration step, thereby reducing manufacturing time and increasing productivity.
3Measurement precision
If dielectric material is added between coil and conductor, then measurement precision improves by reducing capacitance effects, but device complexity increases
Solution Approach 1:
A dielectric material is introduced as an intermediary element between the Rogowski coil and the conductor. This intermediary component reduces unwanted capacitance effects that degrade measurement accuracy, while its simple placement and standard material properties keep the overall structural complexity increase minimal.
4Measurement precision
If transformer sensor devices are used, then measurement precision is maintained, but device volume increases making the meter bulky
Solution Approach 1:
The patent modifies the electrical parameters of the Rogowski coil by introducing a dielectric material, changing the capacitance and inductance characteristics to achieve measurement precision comparable to transformer sensors. This allows the compact Rogowski coil structure to be retained without sacrificing accuracy.
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 provides improved accuracy and reduced calibration requirements, lowering manufacturing costs and time while maintaining high precision across varying current and voltage ranges, and enhanced immunity to electromagnetic interference.
Implementation Method 1
a coil having a dielectric material positioned between the coil and conductor to reduce capacitance
Implementation Method 2
Faraday shields to enhance accuracy and reject electromagnetic interference
Implementation Method 3
sensing current flowing through a conductor between the power source and the user
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Sensor devices and related methods disclosed. One example sensor device (12) includes a substrate (102) comprising a plurality of bobbins (124, 126, 128, 130, 132, 134), the plurality of bobbins defme an aperture (110) structured to receive a conductor (14) therein, a coil (104) comprising a plurality of coil turns wound about each of the plurality of bobbins, a first shield (140) extending between each of the plurality of bobbins and the plurality of coil turns; and a second shield (142) positioned proximate to the plurality of coil turns, opposite the first shield such that the plurality of coil turns is between the first shield and the second shield.