Comprehensive Analysis of Common Fault Diagnosis and Maintenance Strategies for Distribution Transformers

As critical equipment in power systems, the stable operation of distribution transformers directly affects power supply reliability and electricity safety. However, various faults inevitably occur during long-term operation. This article systematically analyzes common fault types, diagnostic methods, and maintenance strategies for distribution transformers to help users promptly identify and resolve issues, extending equipment service life.

1. Common Fault Types and Characteristic Analysis

1.1 Winding Faults

The winding is the core component of a transformer. Common faults include:

• Inter-turn short circuits: Local overheating, abnormal oil temperature rise, gas relay operation
• Winding grounding: Insulation resistance decrease, protection device tripping
• Winding deformation: Short-circuit impedance changes, increased vibration and noise

1.2 Core Faults

• Core multi-point grounding: Abnormal core grounding current increase, local overheating
• Core loosening: Abnormal vibration noise, increased no-load current

1.3 Insulation Faults

• Insulation aging: Insulation material embrittlement, increased dielectric loss factor
• Insulation moisture: Insulation resistance decrease, winding capacitance changes

1.4 External Faults

• Bushing faults: Surface discharge, oil leakage
• Cooling system faults: Abnormal oil temperature, radiator blockage

2. Fault Diagnosis Methods and Technologies

2.1 Traditional Diagnostic Methods

• Sensory inspection: Identifying abnormalities through hearing, sight, and smell
• Electrical tests: Insulation resistance testing, winding DC resistance testing
• Oil analysis: Dielectric loss testing, chromatography analysis, micro-water content detection

2.2 Modern Diagnostic Technologies

• Online monitoring systems:
  • Temperature online monitoring
  • Partial discharge online monitoring
  • Dissolved Gas Analysis (DGA)
• Intelligent diagnostic systems:
  • Artificial intelligence fault prediction
  • Big data analysis
  • Cloud platform remote monitoring

3. Preventive Maintenance Strategies

3.1 Regular Maintenance Schedule

Establish scientific maintenance cycles:

• Daily inspections: Weekly checks of oil level, temperature, noise, etc.
• Quarterly maintenance: Comprehensive inspection every quarter
• Annual overhaul: Power outage maintenance annually

3.2 Condition-Based Maintenance Implementation

Maintenance strategies based on equipment condition assessment:

• Establish equipment health records
• Implement trend analysis
• Develop personalized maintenance plans

3.3 Emergency Response Plans

Develop emergency plans for common faults:

• Sudden short-circuit handling procedures
• Fire accident emergency plans
• Natural disaster response measures

4. Maintenance Considerations

4.1 Safety First

• Strictly implement operating procedures
• Implement safety protection measures
• Use qualified tools and equipment

4.2 Quality Control

• Use genuine spare parts
• Select professional maintenance teams
• Conduct maintenance quality acceptance checks

4.3 Complete Documentation

• Detailed maintenance process records
• Establish equipment maintenance files
• Conduct maintenance effectiveness evaluations

5. Intelligent Operation and Maintenance Development Trends

5.1 Digital Transformation

• Establish digital twin systems
• Implement predictive maintenance
• Adopt drone inspections

5.2 Intelligent Upgrade

• Install intelligent sensors
• Build cloud platforms
• Achieve remote diagnosis

5.3 Standardized Management

• Develop standardized operating procedures
• Establish expert knowledge bases
• Implement lean management

Conclusion:
Fault diagnosis and maintenance of distribution transformers is a systematic project that requires scientific methods and advanced technologies. By implementing preventive maintenance and condition-based maintenance, equipment operational reliability can be significantly improved, failure rates reduced, and service life extended. Users are advised to establish comprehensive equipment management systems and adopt intelligent operation and maintenance methods to ensure the safe and stable operation of distribution transformers.