Leakage current characteristics in estimating insulator reliability: experimental investigation and analysis

Area of Science:

• Electrical Engineering
• Materials Science

Background:

• Transmission line insulators are critical for grid reliability.
• In-service insulator condition monitoring is essential for preventing failures.
• Environmental factors like contamination and wetting significantly impact insulator performance.

Purpose of the Study:

• To develop and evaluate novel leakage current (LC) and voltage-based indicators for assessing the health of porcelain, glass, and silicone rubber insulators.
• To correlate these indicators with environmental factors such as contamination severity and wetting levels.
• To validate the effectiveness of proposed indicators in predicting insulator physical state.

Main Methods:

• Monitoring temporal and frequency characteristics of LC and voltage under diverse environmental conditions.
• Analyzing six key LC indicators derived from time and frequency domains (C1-C6).
• Utilizing the flashover voltage index (C7) and classifying indicators based on laboratory test results.

Main Results:

• Proposed LC indicators demonstrated significant effectiveness in determining the physical state of insulators.
• A confusion matrix analysis confirmed the predictive power of the developed indicators.
• The study established a clear link between environmental factors and insulator health indicators.

Conclusions:

• The developed LC and voltage-based indicators provide a robust method for in-service insulator condition assessment.
• These indicators are crucial for anticipating potential failures and ensuring transmission line reliability.
• The findings support the use of advanced LC analysis for proactive maintenance of electrical insulators.