Voltage Detection Device Bushing Antenna Extraction

Solution Overview

Problem

Conventional gas insulated switchgear faces challenges in detecting main circuit voltages due to issues with cable heads and embedded metals, and the placement of voltage detection devices within the tank leads to size constraints and potential gas leakage.

Innovation Solution

A voltage detection device is implemented by arranging an antenna on the surface of a bushing connected to the external power cable, with a conductive layer cut off to connect to the tank, allowing for external voltage detection without the need for additional gas seals or tank space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a voltage detection device is placed inside the metallic tank, then voltage detection is enabled, but the tank size increases and gas leakage risk increases

Engineering Contradiction:

Improvevoltage detection capabilityVSAvoidtank size

Core Design Contradiction:

Measurement precisionVSVolume of stationary object

Solution Approach 1:

The voltage detection device is extracted from the metallic tank and relocated to the bushing structure. The antenna is mounted on the bushing's conductive layer, which serves as both a structural component and a detection element. This extraction eliminates the need for internal mounting space while maintaining detection functionality through electromagnetic coupling with the main circuit conductor.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The conductive layer on the bushing surface serves multiple functions: it provides electrical connection to the tank, acts as a radiation shield, and functions as an antenna for voltage detection. By integrating these functions into a single component, the invention avoids adding separate detection devices that would increase tank size or require additional gas seals.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If a voltage detection device is placed inside the metallic tank, then voltage detection is enabled, but the number of gas seal portions increases

Engineering Contradiction:

Improvevoltage detection capabilityVSAvoidgas seal integrity

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The voltage detection device is extracted from the metallic tank and relocated to the bushing structure. The antenna is mounted on the bushing's conductive layer, which serves as both a structural component and a detection element. This extraction eliminates the need for internal mounting space while maintaining detection functionality through electromagnetic coupling with the main circuit conductor.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The conductive layer on the bushing surface serves multiple functions: it provides electrical connection to the tank, acts as a radiation shield, and functions as an antenna for voltage detection. By integrating these functions into a single component, the invention avoids adding separate detection devices that would require additional gas seals.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If conventional cable heads with ground layers are used, then cable connection is achieved, but voltage detection through the cable head is not possible

Engineering Contradiction:

Improvecable connection capabilityVSAvoidvoltage detection capability

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The conductive layer on the bushing surface is selectively modified: in some regions it maintains ground connection functionality, while in other regions it serves as an antenna for voltage detection. This local differentiation allows the same component to fulfill both grounding and detection functions without interfering with each other.

Inventive Principle:

Principle #3Local quality

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

This solution enables easy detection of main circuit conductor voltages without increasing the tank's size or risk of gas leakage, while maintaining effective insulation performance.

Implementation Method 1

an antenna 104 that detects a voltage applied to a center conductor 102

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3477310B1Voltage detection device and gas insulation switchgear apparatus having voltage detection device mounted thereon

Publication Date: 2022.06.08 MITSUBISHI ELECTRIC CORP

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AI summary

The present invention is to provide a voltage detection device that can easily detect a voltage of a main circuit conductor. Included are: a bushing which is composed of an external power cable connection portion to be connected to an external power cable and a main circuit conductor connection portion to be connected to a main circuit conductor arranged in a tank, and whose center portion has a center conductor to be connected to the main circuit conductor; a conductive layer which is provided on the surface of the bushing and is connected to the tank; a conductive layer portion in which a part of the conductive layer is cut off; an antenna which is arranged on the cut-off conductive layer portion and detects a voltage applied to the center conductor; and a voltage detector which is arranged outside the tank and is to be connected to the antenna.