Non-Contact Energy Meter Calibration for Accurate Voltage Sensing

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Solution Overview

Problem

Existing energy metering systems face inaccuracies in voltage measurement due to temperature and position dependencies of non-contact voltage sensors, requiring frequent recalibration and leading to unreliable power and energy calculations.

Innovation Solution

An energy metering assembly using a non-contact voltage sensor with calibration by a voltage meter and a controller that adjusts voltage measurements based on temperature and historical data, and a core for current measurement, enabling accurate power and energy determination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a non-contact voltage sensor is used to measure voltage, then the measurement can be performed without direct electrical contact, but the measurement accuracy deteriorates due to temperature and position dependencies

Engineering Contradiction:
Improvenon-contact measurement capabilityVSAvoidvoltage measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system uses a voltage meter to measure the actual voltage and feeds this information back to the controller. The controller then adjusts the non-contact sensor readings based on the difference between the sensor output and the actual voltage measurement, continuously correcting for temperature and position dependencies

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The controller changes the calibration parameters of the non-contact voltage sensor based on temperature sensor readings and position information. By adjusting these parameters dynamically, the system compensates for environmental factors that affect measurement accuracy

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If frequent recalibration is performed to maintain measurement accuracy, then measurement precision improves, but system complexity and time consumption increase

Engineering Contradiction:
Improvevoltage measurement accuracyVSAvoidrecalibration system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs automatic self-calibration by comparing the non-contact sensor output with the voltage meter measurement. The controller automatically adjusts the sensor calibration parameters without requiring manual intervention, reducing operational complexity while maintaining accuracy

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs initial calibration during manufacturing and stores calibration data. This preliminary calibration provides a baseline that reduces the need for frequent recalibration during operation, simplifying the ongoing maintenance requirements

Inventive Principle:
Principle #10Preliminary action

3Reliability

If temperature compensation is implemented to correct sensor drift, then measurement reliability improves, but device complexity increases due to additional temperature sensors and control logic

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidtemperature compensation system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The controller serves multiple functions: it processes voltage measurements from both the non-contact sensor and voltage meter, reads temperature sensor data, performs calibration calculations, and outputs corrected voltage readings. This multi-functionality consolidates components and reduces overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 system provides accurate and reliable power and energy calculations by correcting voltage sensor inaccuracies through calibration, reducing the need for frequent recalibration and enhancing measurement precision.

Implementation Method 1

taking a voltage measurement, via a non-contact voltage sensor, of one or more primary conductors

Methodology Applied
Scientific EffectElectromagnetic field interaction: Electric Field

Implementation Method 2

taking a current measurement of a secondary conductor... determining a current value of the one or more primary conductors based on the current measurement of the secondary conductor

Methodology Applied
Scientific EffectMagnetic field interaction: Magnetic Field

Data Source

PatentEP4390409B1System and method for calibrating a non-contact energy metering assembly
Publication Date: 2026.03.25 SCHNEIDER ELECTRIC USA INC
  • EP4390409B1 patent drawingFigure 1
  • EP4390409B1 patent drawingFigure 2A
  • EP4390409B1 patent drawingFigure 2B

AI summary

This disclosure relates generally to an energy metering assembly configured to measure current and voltage of a one or more primary conductors, the energy metering assembly comprising a core; a coil having a plurality of turns, the coil being positioned around the core when securing the core to the one or more primary conductors; a voltage sensor, the voltage sensor being configured to sense a voltage of a one or more primary conductors; and a controller coupled to the coil and the voltage sensor, the controller being configured to determine a voltage of the one or more primary conductors, determine a current of the one or more primary conductors, and responsive to determining the voltage and the current, determine the power carried by the one or more primary conductors.