What is the safety of an oil type transformer?
Time：2025-04-11 Auther：ZTelec-www.ztelectransformer.com
Structural Characteristics and Safety Considerations of
Functions and Potential Risks of Transformer Oil
In oil-filled transformers, the insulating oil plays a critical role in both insulation and cooling. Its excellent insulating properties effectively prevent electrical breakdown, ensuring stable transformer operation. At the same time, the circulating oil efficiently dissipates heat, maintaining a stable internal temperature. However, transformer oil is flammable and poses a significant safety hazard—under high temperatures or electrical arcing, it can ignite or even explode.
Complexity of Electrical Structure
Oil-filled transformers contain high-voltage windings, low-voltage windings, iron cores, and other electrical components. The insulation and connections between these components must be precise and reliable. Insulation failures or short circuits can lead to localized overheating, discharges, and other hazardous conditions. For example, an interturn short circuit can cause a rapid surge in current, generating excessive heat that may burn out the winding or even ignite the transformer oil.
Operational Safety Risks of Oil Type Transformers
1.Overloading
Prolonged overloading increases current in the windings, generating excess heat. If heat dissipation is insufficient, the temperature of the transformer oil will rise continuously, accelerating oil degradation and reducing its insulating properties. High temperatures can also soften or deform winding insulation, leading to insulation failure and increasing the risk of electrical faults.
2.Insulation Aging
Over time, the internal insulation materials of a transformer gradually degrade. Aged insulation loses effectiveness, increasing the likelihood of partial discharges or breakdowns. For instance, insulation paper exposed to prolonged high temperatures and electric fields may become carbonized or brittle, losing its insulating function and potentially causing safety incidents.
3.External Short Circuits
An external short circuit generates strong electromagnetic forces that can deform or displace windings, damaging insulation structures. Additionally, the high short-circuit current produces significant heat in the windings, raising temperatures and further compromising safe operation.
4.Inadequate Maintenance
Poor maintenance practices—such as delayed oil replacement or clogged cooling systems—can negatively impact transformer performance. Over time, transformer oil accumulates moisture and impurities, reducing its insulating ability. Blocked cooling systems impair heat dissipation, raising temperatures and increasing safety risks.
Measures to Ensure the Safety of Oil Type Transformers
Proper Design and Selection
During design and selection, key parameters such as capacity and voltage rating should be chosen based on actual operational needs to prevent overloading. Additionally, robust insulation structures and high-quality insulation materials should be used to enhance performance.
Enhanced Operational Monitoring
Install comprehensive monitoring systems, including temperature sensors and gas relays, to track the transformer’s condition in real time. By monitoring oil temperature, gas levels, and other parameters, abnormalities such as overheating or internal faults can be detected early, allowing timely corrective action.
Regular Maintenance and Inspections
Implement a detailed maintenance schedule, including oil replacement, cooling system cleaning, and inspections of windings and insulation. Routine maintenance helps identify and address potential hazards, ensuring reliable operation.
Optimized Operating Environment
Ensure transformers operate in a dry, corrosion-free environment with adequate ventilation for heat dissipation. Fireproof and explosion-proof measures, such as firewalls and pressure relief valves, should be installed nearby to mitigate safety risks.
