Leakage Current Sensor for Post-Type Insulator Monitoring

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Solution Overview

Problem

Electrical power transmission systems face issues with leakage currents causing fires and flashovers due to insulator contamination, leading to power outages and material degradation, necessitating a continuous monitoring system to mitigate these risks.

Innovation Solution

A sensor unit is mounted near post-type insulators to detect leakage currents and wirelessly transmit values to a receiver, using a toroidal current transformer and electronics module for processing and communication, allowing for real-time monitoring and reporting of leakage current magnitudes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous leakage current monitoring is implemented, then reliability of power transmission is improved, but device complexity increases

Engineering Contradiction:
Improvereliability of power transmissionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The monitoring system is divided into separate functional modules: a sensor unit for detecting leakage current, an electronics module for signal processing, and a wireless communication module for data transmission. This segmentation allows each component to be optimized independently and simplifies the overall system architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A toroidal current transformer is used as an intermediary device to detect leakage current without direct electrical contact with the high-voltage circuit. The transformer couples the detection function to the power transmission system through magnetic field interaction, providing electrical isolation while enabling continuous monitoring.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of information

If wireless transmission components are added to the sensor, then information reporting capability is improved, but use of energy increases

Engineering Contradiction:
Improveinformation reporting capabilityVSAvoiduse of energy
Core Design Contradiction:
Loss of informationVSUse of energy by moving object

Solution Approach 1:

The wireless transmission is configured to operate periodically rather than continuously. The sensor unit transmits leakage current data at predetermined intervals, which reduces energy consumption while still providing timely information about insulator conditions. This periodic operation allows the battery to last over 10 years.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The sensor unit is designed to be self-powered with an integrated battery, eliminating the need for external power connections that would increase energy consumption and installation complexity. The unit autonomously monitors, processes, and transmits data without requiring additional power infrastructure.

Inventive Principle:
Principle #25Self-service

3Reliability

If insulators are monitored and maintenance actions are taken, then flashover prevention is improved, but loss of time for maintenance operations increases

Engineering Contradiction:
Improveflashover preventionVSAvoidmaintenance time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The monitoring system enables preliminary detection of insulator contamination and leakage current trends before flashover conditions develop. By continuously tracking leakage current and comparing it against threshold values, the system provides early warning that allows maintenance to be scheduled at convenient times rather than responding to emergencies.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system provides continuous feedback about insulator condition through wireless transmission of leakage current data. This feedback loop allows utilities to monitor multiple insulators and prioritize maintenance based on actual condition data, optimizing the allocation of maintenance resources and reducing overall maintenance time.

Inventive Principle:
Principle #23Feedback

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 effectively monitors and reports leakage current issues, enabling timely mitigation of potential problems, reducing the risk of flashovers and wood pole fires, and extending battery life with low power consumption for over 10 years.

Implementation Method 1

A leakage current sensor detects leakage current and wirelessly transmits the leakage current values

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2807493B1Leakage current sensor for post-type insulator
Publication Date: 2019.03.27 ELECTRIC POWER RES INST INC
  • EP2807493B1 patent drawingFigure 1
  • EP2807493B1 patent drawingFigure 2
  • EP2807493B1 patent drawingFigure 3

AI summary

A sensor apparatus for detecting leakage current in a post-type insulator of an electrical power system includes: a sensor unit having a housing, the sensor unit including: a sensor assembly operable to generate an analog signal proportional to a received leakage current; an electronics module operable to covert the analog signal to a digital value; and a communications system operable to wirelessly transmit the digital value to an external receiver; a collection band adapted to be connected to an exterior surface of the insulator; and a transfer lead interconnecting the sensor assembly and the collection band, the transfer lead operable to transfer leakage current from the insulator from the collection band to the sensor assembly.