Capacitive Sensor for DI-Circuit Breaker Ground Voltage Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing DI-circuit breaker devices are ineffective in reliably detecting the protective ground conductor state, especially when users wear insulating gloves or clothing, leading to potential unsafe switch-on scenarios and incorrect impedance detection.

Innovation Solution

A capacitive sensor is integrated into the DI-circuit breaker device, forming an electric capacitor with the user's hand, and evaluating electronics determine the phase position by connecting the sensor to the phase and neutral conductors, assessing the absence of phase voltage on the protective ground conductor, allowing for reliable detection even with insulating barriers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conductive sensor surface is used to detect protective ground conductor state, then voltage detection is enabled, but detection fails when user wears insulating gloves or clothing

Engineering Contradiction:

Improvedetection reliabilityVSAvoidoperation with protective clothing

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent replaces the conductive sensor surface (electrical contact method) with a capacitive sensor that detects voltage through insulation barriers. The capacitive sensor measures capacitive coupling between the voltage source and the user's body, enabling detection without direct electrical contact. This substitution allows operation with insulating gloves and protective clothing while maintaining detection reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The capacitive sensor acts as an intermediary that detects voltage through the insulating barrier (gloves, clothing) without requiring direct contact. The sensor measures the capacitive effect created by the electric field penetrating the insulation, serving as a mediator between the voltage source and the detection system.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If direct electrical contact sensor is used, then simple detection is achieved, but insufficient impedance protection is detected as 'good' state

Engineering Contradiction:

Improvedetection mechanism simplicityVSAvoidimpedance detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces simple conductive contact detection with capacitive sensing that measures impedance characteristics. The capacitive sensor detects the capacitive coupling effect which provides information about the impedance of the protective ground conductor, enabling more precise measurement while maintaining relatively simple device architecture.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If capacitive sensor is used to detect through insulation, then operation with protective clothing is enabled, but sensor signal strength decreases with thicker insulation

Engineering Contradiction:

Improveoperation with protective clothingVSAvoidsensor signal strength

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent employs periodic modulation of the sensing signal to enhance detection capability. The evaluation electronics use periodic excitation signals to measure capacitive coupling, which improves signal-to-noise ratio and enables detection through thicker insulation materials while maintaining sufficient signal strength.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system adjusts sensing parameters (excitation frequency, measurement timing, signal amplification) to optimize detection through different thicknesses of insulation. By changing operational parameters dynamically, the system maintains adequate signal strength regardless of insulation thickness.

Inventive Principle:

Principle #35Parameter changes

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 capacitive sensor provides a reliable and safe method to check the protective ground conductor state, ensuring the absence of voltage and proper impedance, enabling effective operation of the DI-circuit breaker device even with thick protective clothing.

Implementation Method 1

the detection device has a capacitive sensor which, when touched by a user, forms an electric capacitor with a capacitive reactance relative to ground potential

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11228175B2Di-circuit breaker device and operating method for detecting a voltage on a pen conductor

Publication Date: 2022.01.18 HEINRICH KOPP AG

AI summary

A DI-circuit breaker device includes a summation current converter for detecting fault currents in a phase conductor and a neutral conductor, and a detection device for detecting fault states of a protective ground conductor. The detection device detects the presence of a phase voltage on the protective ground conductor as a fault state. The detection device has a capacitive sensor which, when touched by a user, forms an electric capacitor with an impedance relative to ground potential. The detection device further has evaluating electronics adapted to determine a phase position by connecting the sensor to the phase conductor and, separately therefrom, to the neutral conductor. The evaluating electronics determine the absence of a phase voltage on the protective ground conductor when there is no voltage between the neutral conductor and the protective ground conductor when phase is present at the phase conductor. Further, a corresponding operating method is described.