Calibration System for Non-Contact Voltage Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional voltage measurement devices require galvanic contact, posing safety risks and necessitating exposed wires or terminals, while non-contact devices face calibration challenges due to varying coupling capacitances and stray currents.
Innovation Solution
A calibration system for voltage measurement devices that generates a reference current signal, senses it via sensors, and determines calibration data using a controllable calibration voltage source and control circuitry, allowing for non-contact measurement and storage of calibration data for subsequent use, including lookup tables and mathematical formulas to interpolate calibration factors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If galvanic contact measurement is used, then measurement precision is improved, but safety risks increase and exposed wires are required
Solution Approach 1:
The patent replaces the mechanical/galvanic contact measurement system with a non-contact electromagnetic field-based measurement system. The voltage measurement device uses electromagnetic coupling to detect voltage without physical contact, eliminating safety risks while maintaining measurement capability through field-based sensing.
Solution Approach 2:
The patent introduces an electromagnetic field as an intermediary between the measurement device and the voltage source. Instead of direct galvanic contact, the device couples to the electromagnetic field surrounding the conductor, allowing indirect measurement that avoids safety hazards while preserving measurement accuracy.
2Object-affected harmful factors
If non-contact measurement is used, then safety risks are reduced, but measurement precision deteriorates due to varying coupling capacitances
Solution Approach 1:
The patent changes the measurement parameters by measuring multiple quantities (voltage, frequency, phase) and using these varied parameters to compensate for coupling capacitance variations. By analyzing relationships between multiple parameters rather than relying on a single voltage measurement, the system maintains precision despite varying coupling conditions.
Solution Approach 2:
The patent implements feedback mechanisms where the measured voltage, frequency, and phase information is processed to determine coupling conditions, and this information is used to adjust or compensate the measurement calculations. The system uses the measured parameters themselves to correct for the effects of varying coupling capacitance.
3Measurement precision
If multiple calibration points are obtained at varying distances, then calibration accuracy is improved, but device complexity increases
Solution Approach 1:
The calibration system is designed to perform multiple functions: it measures voltage, frequency, and phase simultaneously; it operates at multiple calibration voltages and distances; and it generates comprehensive calibration data that covers various operating conditions. This multi-functional approach consolidates what would otherwise require separate calibration systems for each condition.
Solution Approach 2:
The patent performs comprehensive calibration measurements in advance, obtaining data at multiple voltages, frequencies, and distances before actual use. This preliminary calibration data is stored and used to create lookup tables and calibration curves that simplify subsequent measurements, eliminating the need for complex real-time calculations during operation.
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, non-contact voltage measurement without galvanic contact and accurate calibration across varying distances and voltages, reducing measurement errors and ensuring precise output voltage determination.
Implementation Method 1
non-contact devices face calibration challenges due to varying coupling capacitances
Data Source
Figure 1A
Figure 1B
Figure 2~3
AI summary
Systems and methods for calibrating a voltage measurement device are provided herein. The voltage measurement device generates a reference current signal and senses the reference current signal in a conductor under test. A calibration system may control a calibration voltage source to selectively output calibration voltages in a calibration conductor. The calibration system may obtain data from the voltage measurement device captured by the voltage measurement device when measuring the calibration conductor. Such data may include one or more reference current measurements, one or more voltage measurements, etc. The calibration system utilizes the obtained measurements to generate calibration data which may be stored on the voltage measurement device for use thereby during subsequent operation. The calibration data may include one or more lookup tables, coefficients for one or more mathematical formulas, etc.