Tips for extending the life of power transformers
Five key maintenance and use points to extend the life of industrial power transformers, covering key measures for daily operation, environmental control and preventive maintenance:
- Regular monitoring and inspection: prevent problems before they occur
Temperature monitoring
Use an infrared thermometer to regularly check the transformer casing temperature. The oil temperature of an oil-immersed transformer should be ≤85°C, and the winding temperature of a dry-type transformer should be ≤130°C (H-class insulation). Abnormal temperature rise may indicate overload or heat dissipation failure.
Vibration and noise inspection
Abnormal vibration or continuous buzzing sound may be caused by loose core or deformation of winding, which requires stopping the machine for inspection.
Insulation performance test
Carry out insulation resistance test (using megohmmeter) at least once a year to ensure that the insulation resistance of the winding to ground is ≥1MΩ/kV. If it is lower than the standard, it needs to be dried or the insulation material needs to be replaced.
- Reasonable load management: avoid long-term overload
Dynamic load control
The instantaneous load peak shall not exceed 1.2 times the rated capacity, and the continuous operating load rate shall be controlled within 80% to avoid accelerated insulation aging due to long-term full load.
Three-phase load balancing
The three-phase current imbalance should be ≤10%. Long-term imbalance will cause local overheating and shorten the service life. You can use a clamp ammeter to check regularly.
Seasonal capacity adjustment
When the temperature is high in summer or low in winter, adjust the load according to the ambient temperature (such as reducing the capacity by 5%-10% in summer) to reduce the impact of thermal stress.
- Environmental control: optimizing operating conditions
Enhanced ventilation and heat dissipation
Ensure that there is no obstruction around the transformer for ≥1 meter. Forced air cooling equipment requires regular cleaning of fan dust and keeping the air inlet/outlet unobstructed.
Moisture and condensation proof
In places with high humidity (such as coastal areas), install heating dehumidification devices or sealed protective covers to prevent the windings from getting damp and causing insulation breakdown.
Dust and corrosion protection
In dusty environments, clean the heat sink every month. In corrosive gas environments (such as chemical plants), use epoxy resin to encapsulate the Dry-Type Transformer or apply an anti-corrosion coating.
- Scientific maintenance: cleaning and parts replacement
Oil Immersed Transformer maintenance
The transformer oil breakdown voltage (should be ≥30kV) and acid value (≤0.1mg KOH/g) should be tested annually. If the values exceed the limit, the oil should be filtered or replaced.
- The sealing gasket needs to be replaced in time if it is aged (such as oil leakage) to prevent air and moisture from entering.
Dry-type transformer cleaning
After a power outage, use dry compressed air to blow away dust on the surface of the winding. Wipe stubborn stains with anhydrous ethanol and avoid using chemical solvents.
- Preventive testing and professional maintenance
Periodic Testing Program
Perform no-load loss test and short-circuit impedance test every 3-5 years and compare with factory data. If the deviation exceeds 5%, in-depth troubleshooting is required.
Key points for professional maintenance
- If the winding is loose, it needs to be re-painted and reinforced. If the core grounding is poor, it needs to be re-welded.
- Replace aged bushings, tap changers and other vulnerable parts to avoid failures caused by partial discharge.
Summarize
The key to extending transformer life is "prevention first, precise maintenance":
- Reduce thermal damage through temperature control and load management;
- Optimize the environment to reduce external erosion risks;
- Regular cleaning and component updates to maintain performance;
- Professional testing provides early warning of potential failures.