Comprehensive Analysis of Transformer Insulation Status Monitoring and Maintenance

Writer： Hengfeng you electric Time：2026-04-03 views：times

The insulation system is the core protective component of a transformer, and its performance directly determines the operating life and safety stability of the equipment. During long-term operation, insulation performance gradually deteriorates due to the influence of temperature, electric fields, humidity, and impurities. The key to preventing failure lies in combining offline testing with online monitoring and implementing refined maintenance for different types of equipment.
I.Insulation Status Monitoring: Accurate Diagnosis of Health Level

The core of monitoring lies in identifying signs of moisture, aging, and discharge in the insulation system through multi-dimensional data comparison.

Offline Testing (Routine Check-ups) Insulation Resistance Measurement: Using a megohmmeter to determine if the windings are damp or if surface contamination exists. Dielectric Loss Factor Test: An effective means of evaluating overall insulation aging and severe moisture issues. Dissolved Gas Analysis (DGA): Specifically for oil-immersed transformers, this involves analyzing the composition of gases dissolved in the oil (such as acetylene, hydrogen, etc.) to detect hidden defects like internal overheating or discharge in advance.

Online Monitoring (Real-time Warning) Real-time capture of abnormal signals such as partial discharge, oil quality degradation, and insulation temperature rise. Its advantage lies in identifying sudden defects, enabling a transition from periodic maintenance to condition-based maintenance.
II. Differentiated Maintenance Strategies: Targeted Measures Based on Type

Dry-type and oil-immersed transformers have different maintenance priorities due to their different structures.

Dry-Type Transformers: Dust Removal, Moisture Prevention, and Crack Prevention Environmental Governance: Keep the installation environment ventilated and dry; dehumidification equipment should be operated during humid seasons. Dust Maintenance: Regularly clean dust accumulation on windings and core using dry compressed air to prevent insulation decline caused by dust. Visual Inspection: Check the cast body for cracks or peeling, and perform insulation repairs promptly if damage is discovered.

Oil-Immersed Transformers: Oil Quality Preservation, Leak Prevention, and Temperature Control Oil Quality Refinement: Regularly test oil quality, and filter or replace the oil promptly when degradation occurs. Sealing Assurance: Check the sealing of the oil tank and bushings to prevent moisture and impurities from entering. Temperature Management: Strictly control operating oil temperature to avoid high temperatures accelerating the aging of the oil and solid insulation. Research shows that excessive operating temperatures significantly shorten insulation life.
III.Standardized Processes and Management Recommendations

Daily insulation maintenance should form a standardized system to improve maintenance efficiency:

Data Closed-loop Management: Complete preventive tests according to cycles, retain data to compare trends, and analyze the rate of degradation rather than just looking at isolated values. Environmental Optimization: Improve the operating environment and stay away from corrosive gases, dust, and accumulated water. Pre-operation Control: After new commissioning or overhaul, sufficient air venting and drying treatment must be performed to ensure the initial insulation status meets standards. Intelligent Upgrading: Combine intelligent monitoring means to reduce manual maintenance costs and improve the accuracy of fault warnings.

IV.Summary

Insulation is the lifeline of a transformer. Routine monitoring and refined maintenance can effectively delay insulation degradation and reduce the risk of failure. Through scientific management methods, transformers can maintain a safe and efficient operating state for a long time, providing reliable protection for the stable power supply of the power system.