24V Battery Pack ,Large Battery Pack,24 V Battery Pack,24V Lithium Ion Battery Pack Zhejiang Casnovo Materials Co., Ltd. , https://www.casnovonewenergy.com
Oil immersed transformer classification
Transformers can be classified in various ways based on their design, application, and construction. One of the primary classifications is by the number of phases. A transformer can either be a three-phase or a single-phase unit. In most three-phase power systems, a three-phase transformer is commonly used. However, when the capacity is very large and transportation limitations are a concern, three single-phase transformers can be combined to form a three-phase transformer bank, offering flexibility and ease of transport.
Another way to categorize transformers is by the number of windings. The most common type is the two-winding transformer, which has one primary winding and one secondary winding. These are typically used for voltage transformation between two different levels. For more complex applications, such as connecting three different voltage levels, a three-winding transformer is used. These are usually found in larger power systems with capacities exceeding 5,600 kVA. In some cases, transformers may have more than three windings to meet specific requirements.
In terms of structure, transformers can be either core-type or shell-type. In a core-type transformer, the windings are wrapped around the iron core, while in a shell-type transformer, the core surrounds the windings. Although the structural differences are minimal, the core-type is more commonly used in power transformers due to its efficiency and cost-effectiveness.
Based on insulation and cooling methods, transformers are divided into oil-immersed and dry-type types. Oil-immersed transformers use transformer oil to enhance both insulation and cooling. This method is widely used in high-capacity power systems. Dry-type transformers, on the other hand, are often used in environments where flammability is a concern, such as in street lighting, mines, or indoor installations where oil-based systems are not suitable.
In addition to standard types, there are many special-purpose transformers. These include test transformers for high-voltage testing, furnace transformers for industrial heating, welding transformers, and instrument transformers like voltage and current transformers used in metering systems.
When it comes to oil-immersed power transformers, heat generated by the windings and core is transferred to the surrounding oil, which then dissipates the heat through natural or forced cooling methods. Cooling methods vary depending on the transformer’s size and application:
1. Natural oil circulation with natural cooling (oil-immersed self-cooling)
2. Natural oil circulation with air cooling
3. Forced oil circulation with water cooling
4. Forced oil circulation with air cooling
Under normal operating conditions, oil-immersed transformers are designed for altitudes up to 1,000 meters, both indoors and outdoors. They can operate in ambient temperatures ranging from -25°C to +40°C, with a maximum daily average temperature of +30°C and an annual average of +20°C. Special transformers designed for extreme conditions are also available upon request.