Capacitive Voltage Sensor Shielding Design
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Solution Overview
Problem
Existing capacitive and combined voltage/current sensors are not suitable for estimating the voltage value of a live conductor without being influenced by surrounding electric fields, are laborious to manufacture, prone to partial discharges due to air bubbles and detachment of dielectric resin, and require on-site calibration.
Innovation Solution
A constructive system comprising a first tubular element as a source electrode connected to the live element, a second tubular element as a shielding electrode connected to ground, an electric field sensor positioned between them, and a mass of dielectric material to shield unwanted electric field lines, allowing independent measurement of the electric field generated by the live element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a capacitive sensor is designed to estimate voltage without being influenced by surrounding electric fields, then measurement precision is improved, but device complexity increases due to the need for shielding structures
Solution Approach 1:
The patent implements a nested tubular structure where the first tubular element (source electrode) is positioned inside the second tubular element (shielding electrode). This nested configuration creates a compact, integrated shielding system that blocks surrounding electric fields while maintaining a simple overall structure, thereby improving voltage measurement precision without significantly increasing device complexity.
Solution Approach 2:
The dielectric material serves as an intermediary substance that fills the space between the source electrode and shielding electrode, as well as between the sensor components and the external environment. This intermediary dielectric layer provides electrical isolation and field distribution control, enabling accurate voltage estimation while simplifying the structural design through a unified encapsulation approach.
2Reliability
If dielectric material resin is applied around sensor components, then reliability is improved by preventing partial discharges, but manufacturing precision deteriorates due to air bubbles and detachment issues
Solution Approach 1:
The patent applies the dielectric material resin to the sensor components before final assembly and calibration. This preliminary application ensures that the dielectric material is already in place to prevent partial discharges during subsequent handling, installation, and operation, while allowing adjustments to be made after the dielectric layer is set, thereby maintaining both reliability and manufacturing precision.
Solution Approach 2:
The dielectric material is applied with specific attention to critical areas where partial discharges are most likely to occur, such as around the tubular electrodes and at component interfaces. This localized quality approach ensures reliable protection against discharges while minimizing the overall amount of resin required, reducing the risk of air bubbles and detachment issues.
3Ease of manufacture
If the sensor structure is simplified for easier manufacture, then ease of manufacture is improved, but measurement precision deteriorates due to inadequate shielding
Solution Approach 1:
The dielectric material serves multiple functions simultaneously: it provides electrical insulation, distributes electric fields uniformly, protects against partial discharges, and structurally bonds the sensor components together. This multi-functionality allows the sensor to achieve adequate shielding and measurement precision while maintaining a simple, easy-to-manufacture structure without requiring complex separate shielding components.
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 accurate voltage estimation of live elements without interference from nearby conductors, simplifies manufacturing by preventing air bubbles and resin detachment, and eliminates the need for on-site calibration.
Implementation Method 1
a mass of dielectric material to shield unwanted electric field lines, allowing independent measurement of the electric field generated by the live element
Implementation Method 2
an electric field sensor positioned between them, and a mass of dielectric material to shield unwanted electric field lines, allowing independent measurement of the electric field generated by the live element
Data Source
Figure 1
Figure 1A
Figure 2~6
AI summary
_A constructive system for estimating the voltage value of a live element (10) comprises: a first tubular element (100), a second tubular element (200), an electric field sensor (300) and a mass of dielectric material (400). _The first tubular element (100) perform the source electrode function and is connected by conductive coupling with said live element (10). _The second tubular element (200) acts as a shielding electrode and is connected to ground. _The electric field sensor (300) performs the function of detecting the electric field generated by said first tubular element (100). _The mass of dielectric material (400) performs the function of incorporating and positioning said elements (100, 200, 300) between them.