Oil Immersed Transformer

As one of the professional oil filled transformer manufacturers, our oil immersed type transformer is specially developed and designed based on the advanced technology abroad for rough mountainous topography and transportation difficulties to meet the requirement of China oil type transformer Grid at a good oil immersed transformer price. The main characters of the oil filled transformer are low loss, low noise, and strong resistance of short circuit and free of core checking. We offer different oil immersed transformer types including 220KV Power Transformer, 110KV Power Transformer, 35 kv transformer and earthing transformer. Contact us to get more about oil immersed type now!

Oil Immersed Transformer Types

220KV Power Transformer

220KV series oil immersed power transformer produced with global advanced technology and equipment, continuously updating the manufacturing experience and processing. We developed high-grade power transformer that sufficiently satisfy the operation conditions of domestic and foreign power grid.

110KV Power Transformer

110KV oil-immersed power transformers strictly designed and produced with the IEC standard and most advanced technology have great reputation and the best sell performance all over the world.

35KV Power Transformer

35KV oil-immersed power transformers designed and manufactured with the IEC standard keep reliable working performance and excellent selling record for decades.

Earthing Transformer

Earthing transformers manufacturing with advanced equipment and experience have the characteristics of low loss, low noise, strong protection for lightning and short-circuit resistance.

How to Choose a Transformer: Dry Type vs. Oil Cooled

There are two types of transformers in the industry: dry type power transformer chinese and oil immersed transformer. Dry use air as the cooling medium, liquid cooling uses oil. Although the final results of both types are the same, there are still many differences between different types of power transformers, which will affect the type you choose.

Maintenance: Oil immersed type transformers require more maintenance procedures, and are more often performed than dry type power transformers. Oil sampling is required to test contaminants, while dry type transformers are very resistant to chemical contaminants.

Cost (initial and operational): Dry type transformer has higher operating losses than oil immersed one. And the advantages of dry type transformer over oil cooled transformer is that it has higher standard energy efficiency, so it has longer service life than a dry type transformer.

Noise: The operating sound pressure of oil immersed transformer such as the 110 kv transformer is lower, so it has less noise pollution than a dry type transformer.

Recyclability: Life cycle recovery of dry type transformer is limited, while core/volume recovery of oil immersed one is easier. Our oil immersed transformer has excellent service life and maintainability, and produces less waste, and requires less replacement and labour.

Efficiency: Dry type power transformers are larger devices, but their voltage and size are limited, and they are more likely to overheat if overload happens. As a result, dry type transformers have higher power losses and cost more to keep dry power over time. Oil immersed distribution transformers are smaller and more efficient. They need less and create smaller environmental footprints.

Voltage capacity: Dry type transformer is designed to deal with medium and small MVA and rated voltage, making it an ideal choice for small applications. Oil immersed distribution transformer can bear a heavier load, so it is for higher voltage application.

Location: The location difference between oil and dry transformers will be the critical determinant of which type you need. Dry type is specified for use near buildings and buildings only because they are safer for the environment. Dry type power transformer is not flammable and has little fire hazard, which makes it very suitable for large shopping centres, hospitals, residential quarters and other commercial areas. Oil filling transformers will be used when installed outdoors, which may cause oil leakage and may cause fire, but these equipment are more environmentally friendly."

What Is the Purpose of Oil in a Transformer?

First, oil insulation is used to cover all parts that do not have solid insulation in the power transformer main body. Oil in a transformer also penetrates into the paper and fills the air gap, thus improving the quality of the paper insulation.

Another purpose of oil in a transformer is to spread heat from the core to the radiator, in which heat can be more easily distributed to the outside.

Maintenance of the Oil in a Transformer

1. Prevent impurity, damp, water and polluted air from entering into oil tank when filtering and filling insulation oil into the tank. It is prohibited to filter oil from one tank to another tank in a rainy day.

2. The oil container must be cleaned strictly and sealed completely. Or the container must be equipped with dehumidifier if the container is not sealed completely.

3. Generally please use as far as possible the insulation oil provided by manufacturer. If it’s necessary to complement other type of oil, it must comply with regulations of mixing oil, and the oil should be tested by specific department to make sure of their compatibility. If the two types of oil are not compatible, it’s prohibited to use mixed oil.

4. Transformer oil must meet the following technical specifications in Table 1.

Oil Immersed Transformer Parts

1. Core

① The core is made of high magnetic permeability silicon steel to reduce load loss and noise of transformer.

② The multistage step lapped core shall be cut with a 45°joint seam, and pore-free binding construction, which reduces the noise as well as power consumption. The burrs are less than 0.02mm.

③ The core is rigidly clamped with insulated clamping bolt, or by other method, between the core column and winding which will retain its shape under the most severe stresses encountered during shipment and handling and under short-circuit conditions.

2. Winding

3.Tank and assembly

4. Cooling plant and accessories

Difference between Dry Type Transformer and Oil Immersed Type Transformer

Dry Type Transformer

For dry type power transformers, an insulation system is needed to maintain their low temperature, so these devices are larger and use larger coils than the oil immersed type transformers at the same rated voltage/capacity. In addition, dry type transformers use more materials, resulting in higher costs. In terms of performance, the power distribution unit can operate at a higher temperature because the natural cooling mechanism is not always stable and is susceptible to the surrounding environment, which leads to shorter service life.

Our dry type power transformers service life: 20 to 25 years.

Oil Immersed Type Transformer

As one of manufacturers of transformers, we will do our best to meet all the needs of customers.