Capacitive AC Voltage Sensing With Dynamic Reference Comparison
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing voltage sensing technologies require direct electrical connections, which are impractical or unsafe for high voltages, and lack the capability to accurately characterize AC voltage magnitude and phase without complex and costly circuits.
Innovation Solution
A non-contact AC voltage sensing system using a conductive sense component capacitively coupled to a conductor, combined with a comparison circuit and analysis circuit to sense AC voltage characteristics by comparing against variable reference voltages, allowing for low-cost and efficient determination of voltage magnitude, phase, and frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct electrical connection (galvanic connection) is used for voltage sensing, then measurement precision is improved, but device complexity and safety requirements increase for high voltage applications
Solution Approach 1:
The patent introduces a conductive sensing component as an intermediary element that capacitively couples to the high voltage conductor without direct galvanic connection. This intermediary component transfers voltage information through capacitive coupling while maintaining electrical isolation, thereby achieving accurate voltage sensing without the complexity of high voltage isolation circuits.
Solution Approach 2:
The patent replaces the traditional galvanic (direct electrical) connection mechanism with a capacitive coupling mechanism. By using the conductive sensing component in proximity to the conductor, the system substitutes direct electrical contact with field-based capacitive interaction, eliminating the need for complex isolation barriers while maintaining measurement capability.
2Device complexity
If non-contact voltage sensing is used, then device complexity is reduced, but measurement precision deteriorates due to weak capacitive coupling signals
Solution Approach 1:
The patent employs dynamic reference voltage adjustment where the second reference voltage changes state based on the comparator output. This dynamic adjustment allows the system to adapt to different voltage levels and maintain measurement precision across varying conditions, overcoming the limitations of fixed reference voltage systems while keeping the circuit simple.
Solution Approach 2:
The patent implements a feedback mechanism where the comparator output feeds back to adjust the reference voltage level. This feedback loop enables the system to automatically compensate for signal strength variations and maintain accurate voltage characterization despite the weak capacitive coupling, thereby improving measurement precision without increasing circuit complexity.
3Device complexity
If fixed reference voltage is used in comparison circuit, then device complexity is reduced, but adaptability to different voltage levels deteriorates
Solution Approach 1:
The patent transforms the static reference voltage into a dynamic one that automatically adjusts based on the sensed voltage level. The reference voltage changes state in response to comparator feedback, enabling the circuit to adapt to different voltage levels without requiring multiple fixed reference circuits or complex programmable voltage sources, thus maintaining simplicity while improving adaptability.
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 characterization of AC voltage without complex circuits, facilitating applications such as energy monitoring and load balancing in power systems, while reducing installation costs and complexity.
Implementation Method 1
a first conductive sense component for positioning, when in use, in non-contacting proximity to a first conductor so as to capacitively couple with the first conductor to generate a first AC sensing signal at the first conductive sense component, wherein the first AC sensing signal is dependent on a first AC voltage of the first conductor
Data Source
AI summary
Non-contact AC voltage sensing systems, methods and circuits are described. An example comprises a conductive sense component for positioning, when in use, in non-contacting proximity to a conductor to capacitively couple with the conductor to generate an AC sensing signal at the conductive sense component, wherein the AC sensing signal is dependent on an AC voltage of the conductor. The system also comprises a comparator comprising: a first input coupled to the conductive sense component, a second input, and an output to output a first comparison signal indicative of which of a first potential at the first input and a second potential at the second input is higher. Either input of the comparator is biased by a variable reference voltage. The system comprises an analysis circuit coupled to the output of the comparator and configured to sense the AC voltage based on the variable reference voltage and the comparison signal.