Transformer maintenance, aging and testing. Life-extension services. Moisture reduction. Reliability.

1. Transformer Maintenance
and Reliability
Aris Peña, CRL
Senior Business Development
Manager

2. • Introduction
• Maintenance, aging
and testing
• Life-extension services
• Moisture reduction
• Reliability
• Conclusions
Content Overview

3. • Maintenance and reliability
are inseparable
• Influencing factors in
maintenance decisions
• Maintenance and monitoring
methods
Introduction

4. Maintenance, Aging and Testing
Corrective Maintenance
Reacting to problems when they occur
Preventive Maintenance
Routine repairs and maintenance
Predictive Maintenance
Utilizes trending data for optimal performance

5. Maintenance, Aging and Testing
Life of transformer = Life of paper
Oxidation
attacks and
destroys paper

6. Life-extension Services
Acid level in oil: Data from 5,000+ transformers
Non-serviced group: Elevated acid levels
Average acid level: 0.11 mg KOH/g
Serviced group: Oil reclamation had been performed
Average acid level: 0.03 mg KOH/g

7. 0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0 10 20 30 40 50 60 70 80 90 100
AcidNo.(mgKOH/g)
Age (Years)
Acid Number as a function of Age
(5,839 oil-filled transformers >500 kVA)
Non-serviced (1,675)
Serviced (4,164)

8. Life-extension Services
Acids attack insulating paper
Insulating paper loses tensile strength
The paper is irreversibly weakened
WHEN PAPER STRENGTH
DECREASES, THE RISK
OF FAILURE INCREASES

9. 750x Magnification
Acid’s Effect on Paper: 0.05% Acid

10. 750x Magnification
Acid’s Effect on Paper: 0.30% Acid

11. Life-extension Services
Study of 1,534 oil-filled transformers
Oil services include…
• Reclamation
• Moisture Reduction
• Oxidation Inhibitor Restoration

12. Life-extension Services

13. Moisture Reduction
Passive online drying systems
Specs:
38,000 liters
Primary:
345 kVA
Secondary:
154 kVA
Duration:
12 months on
11 months off

14. Reliability
Looking to the future
A contingency plan is essential
• Spare transformer
• Double-connected
substation
• Available rental
• Mobile substation

15. Reliability

16. Reliability

17. Reliability

18. Reliability

19. Reliability

20. DGA Monitoring
Reliability

21. • Degassing
• Removal of Acid and Sludge
• Moisture Reduction
• Processing | Equipment
• Fault Gas Monitoring
• Inspection and Repair
• Regasketing
• Full Electrical Testing
Reliability Actions
Transformer PM and PdM Strategies

22. DGA Monitoring
• 1-gas monitor
Hydrogen present in most faults
• 8-gas monitor
Very effective solution
Higher-budget applications
• Intuitive data presentation
• Complete data management system

23. Data Management
Transformer Dashboard®
Mechanical and
Maintenance
Fluid
Analysis
Health
Center
Monitor
Data
ET and IR
Data

24. Assessing risk is essential to securing a
reliable electrical system
Aging infrastructure demands an ambitious
maintenance strategy
Proactive steps contribute to valuable
uptime and life extension
Conclusions

25. Aris Peña
Business Development
Representative
Thank you!