Self-Powered Energy Metering Device Using Capacitor Discharge

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Solution Overview

Problem

Existing electrical energy metering devices rely on external power sources or rechargeable batteries, limiting their autonomy and precision in measuring current and power, as they are not operational at all times.

Innovation Solution

An electrical energy metering device that integrates a thyristor-type switch and a voltage reference component with low leakage current, allowing for energy self-sufficiency by using a capacitor for energy integration and transmission, with pulse count data and zero-crossing detection for accurate energy messaging, and correction mechanisms for data accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a battery or external power supply is used, then the device can operate, but the device loses autonomy and may not be operational at all times

Engineering Contradiction:

Improveoperational continuityVSAvoidautonomy

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The device uses the electrical energy from the primary circuit to charge a capacitor, which then powers the measurement and transmission functions. This self-powered approach eliminates dependency on external batteries or power supplies, achieving both operational continuity and autonomy.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The device operates in periodic cycles: the capacitor charges during periods when current flows through the sensor, then discharges to power measurement and transmission. This periodic charge-discharge cycle enables continuous operation without external power sources.

Inventive Principle:

Principle #19Periodic action

2Device complexity

If simple measurement circuits are used, then the device is simpler, but measurement precision of current and power is insufficient

Engineering Contradiction:

Improvecircuit simplicityVSAvoidcurrent and power measurement accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The capacitor acts as an intermediary energy storage element that accumulates energy from the primary circuit and releases it for measurement and transmission. This intermediary mechanism enables precise measurements without requiring complex external power infrastructure.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces mechanical or external power supply systems with an electrical capacitor-based energy storage and release mechanism, enabling precise electronic measurements while maintaining device simplicity and autonomy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If energy is transmitted continuously, then data accuracy is improved, but energy consumption increases

Engineering Contradiction:

Improveenergy data accuracyVSAvoidtransmission energy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The device transmits energy data periodically based on capacitor charge-discharge cycles rather than continuously. This periodic transmission maintains data accuracy by capturing energy at distinct intervals while significantly reducing overall energy consumption compared to continuous transmission.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The capacitor ensures continuous operation of the measurement circuit by storing energy during high-current periods and releasing it during low-current periods, maintaining measurement continuity without requiring continuous external power supply or continuous transmission.

Inventive Principle:

Principle #20Continuity of useful action

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 continuous operation without external energy sources, providing precise energy measurements by correcting for non-linearity and leakage current errors, ensuring reliable energy data transmission and calculation of phase shift between voltage and current.

Implementation Method 1

a capacitor (9) for integrating the current Ir

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

said switch means are composed of a component of the thyristor type which stops conducting below a holding current

Methodology Applied

Scientific EffectThyristor conduction control:

Implementation Method 3

said detection means are in a voltage reference component with low leakage current at the input

Methodology Applied

Scientific EffectVoltage reference:

Implementation Method 4

at least one current sensor for supplying a secondary measurement current representative of a primary current

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2354799B1Device and method for metering electric energy

Publication Date: 2017.04.05 SCHNEIDER ELECTRIC IND SAS

AI summary

The device has a voltage threshold detector (12) connected to an electric current integration capacitor (9) for detecting a passage of a preset voltage threshold value on the capacitor. A switch (13) i.e. thyristor, is controlled by the detector to trigger an electric supply of a processing circuit (10) and an emitter (11) with an energy stored in the capacitor when electric voltage on the capacitor exceeds the threshold value. The circuit and the emitter emit an energy message representing electric energy quantity or quantity of electric current circulated in a primary electric conductor. The energy message is energy metering data, pulse metering data and current quantity metering data. An independent claim is also included for a method for metering electric energy.