Integrated Capacitive Voltage Sensor for Compact Switchgear

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Solution Overview

Problem

Conventional voltage sensors in circuit breakers and reclosers increase the mass and dimensions of the overall unit, decrease reliability due to additional wire bundles, and raise costs when externally mounted.

Innovation Solution

Integration of a capacitive voltage sensor within the insulating casing of the circuit breaker or recloser, utilizing a dome-shaped capacitor between the terminals adjacent to a low potential surface, which includes a current sensor coil, to monitor voltages without increasing the overall dimensions or mass significantly and improve reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional external voltage sensors are used, then voltage monitoring function is achieved, but mass and dimensions of the overall unit increase

Engineering Contradiction:

Improvevoltage monitoring functionVSAvoidmass of overall unit

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The voltage sensor is integrated within the insulating casing of the circuit breaker, merging the voltage monitoring function with the existing structural components. The capacitive voltage sensor uses the insulating casing itself as part of the voltage sensing mechanism, eliminating the need for separate external sensor units and reducing overall mass.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If conventional external voltage sensors are used, then voltage monitoring function is achieved, but dimensions of the overall unit increase

Engineering Contradiction:

Improvevoltage monitoring functionVSAvoiddimensions of overall unit

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The voltage sensor components are nested within the existing insulating casing structure. The capacitive voltage sensor is positioned inside the casing, utilizing the internal space rather than adding external protrusions, thereby maintaining compact dimensions.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Reliability

If conventional external voltage sensors are used, then voltage monitoring function is achieved, but reliability decreases due to additional wire bundles

Engineering Contradiction:

Improvevoltage monitoring functionVSAvoidwire bundles

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The voltage sensor is integrated within the insulating casing, merging the voltage monitoring function with the existing structural components. The capacitive voltage sensor uses the insulating casing itself as part of the voltage sensing mechanism, eliminating the need for separate external sensor units and reducing overall mass.

Inventive Principle:

Principle #5Merging (Combining)

4Reliability

If conventional external voltage sensors are used, then voltage monitoring function is achieved, but mounting cost increases

Engineering Contradiction:

Improvevoltage monitoring functionVSAvoidmounting cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

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 effective voltage monitoring without enlarging the circuit breaker or recloser's pole size, with a small increase in mass, and enhances reliability by integrating the voltage sensor and its circuitry into the main body, reducing the need for external components and associated wire bundles.

Implementation Method 1

a voltage sensor for sensing a voltage at the first electrical terminal, wherein said voltage sensor comprises a voltage divider having a voltage input connected to said first electrical terminal, a voltage output between said voltage input and a voltage reference, and a first capacitor connected between said voltage input and said voltage output

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS12087524B2Voltage sensor for electrical switchgear and electrical switchgear comprising same

Publication Date: 2024.09.10 TAVRIDA ELECTRIC HLDG

AI summary

A circuit breaker includes a capacitive voltage sensor located within its insulating casing. The voltage sensor includes a capacitor located between the terminals of the circuit breaker adjacent a low potential surface provided by a coil of a current sensor. The capacitor is dome shaped. The voltage sensor does not appreciably increase the size or weight of the circuit breaker and is reliable and accurate.