What Are The Dangers of Oil-immersed Transformer Oil Temperature Is Too High Or Too Low

What are the dangers of oil-immersed transformer oil temperature is too high or too low

Oil-immersed transformer oil temperature is too high or too low will bring a series of hazards.

The oil temperature is too high harm

Insulation aging accelerated:

Transformer oil at high temperatures will accelerate the aging, reduce its insulating properties. As the oil temperature rises, the viscosity of the oil decreases, fluidity increases, but also will make the oil in the water, impurities and other easier to move and gather, thus reducing the insulation strength.

Insulating materials such as insulating paper, insulating paint, etc. will also accelerate aging at high temperatures, loss of elasticity and mechanical strength, resulting in a decline in insulation performance, increasing the risk of transformer failure.

Winding overheating damage:

High oil temperature will increase the resistance of the transformer windings, resulting in increased heating of the windings. If the temperature exceeds the permissible temperature of the winding, it will cause the insulation layer of the winding to be damaged, and even short circuit failure.

Long-term high-temperature operation will also reduce the mechanical strength of the windings, prone to deformation, cracking and other problems, affecting the normal operation of the transformer.

Oil oxidation and degradation:

High temperature will accelerate the oxidation reaction of the transformer oil, so that the acid value of the oil, precipitates and other increases, reducing the quality of oil. The oxidised oil will produce acid, which will further corrode the metal parts of the transformer, such as iron core and winding.

Deteriorated oil will also affect the cooling effect, so that the oil temperature rises further, forming a vicious circle.

Misoperation of protective devices:

When the oil temperature is too high, the temperature protection device of the transformer may operate incorrectly, causing the transformer to trip, affecting the normal operation of the power system.

Frequent malfunctioning will also increase maintenance costs and outage time, causing inconvenience to users.

The hazards of low oil temperature

Poor fluidity of oil:

When the oil temperature is too low, the viscosity of the transformer oil increases, poor fluidity. This will affect the oil circulation and heat dissipation effect, so that the heat inside the transformer can not be emitted in a timely manner, resulting in local temperature rise.

Poor fluidity of the oil may also form a blockage in the cooling system, affecting the cooling effect.

Insulation degradation:

At low temperatures, water and impurities in the oil may precipitate and deposit at the bottom of the transformer or on the surface of the insulation, reducing insulation performance.

Insulating materials also become brittle and hard at low temperatures, and are prone to cracks and damage, affecting the safe operation of the transformer.

Malfunctioning of protective devices:

Some transformer protective devices may malfunction when the oil temperature is too low. For example, pressure relief valves may open incorrectly at low temperatures, causing transformer oil to leak.

Malfunctioning protective devices will affect the normal operation of the transformer, increasing maintenance costs and outage time.