220kV Oil-immersed Power Transformers

1. Isolation efficiency

Transformer oil has excellent insulation performance, high breakdown voltage, can effectively isolate high voltage

The fully sealed structure prevents moisture intrusion and maintains stable insulation performance

The 220kV transformer has passed the 50kPa vacuum sealing test to ensure no leakage

2. Transmission-distribution AC

Enable long-distance high voltage transmission and reduce line losses

Voltage level conversion at substations to meet different user needs

Low no-load loss and significant operating economy

3. Voltage Flexible Conversion

Precise control of the secondary terminal voltage by adjusting the number of working turns of the high voltage winding

The tap changer provides a voltage regulation range of ±5% or ±2× 2.5%

To meet the demand for stable power supply in case of voltage fluctuations in the grid

4. Cost-effectiveness

Design life ≥ 30 years, far more than ordinary products (20-25 years)

Long maintenance cycle, moisture absorber silicone replacement cycle ≥ 5 years

The full life cycle cost is more than 25% lower than that of its peers

5. Simple and reliable operating principle

Based on the law of electromagnetic induction, energy transfer is stable

Strong structure, strong resistance to short circuit, passed GB/T1094.5 short circuit test

High mechanical strength, resistant to transport shock

Classification by core structure:

• Stacked iron core transformer: the most commonly used structure, used for high voltage power transformers
• Roll iron core transformer: energy-saving design, commonly used on power distribution networks
• Amorphous alloy transformer: no-load loss is reduced by about 80%, and energy saving effect is ideal

Classification by function:

• Buck Transformer: Drop 220 kV high voltage to 110 kV, 35 kV and other medium voltage levels
• Isolation Transformer: Realize electrical isolation to ensure the safety of system operation

The 220kV oil-immersed transformer adjusts the turn ratio of the winding to increase or decrease the voltage.

1. Regional substations

Connecting the 220 kV trunk network with the 110 kV/35 kV distribution network, it can serve as a hub node of the power system to realize energy distribution

2. Industrial projects

It can provide stable power supply for the total reduction substation of large enterprises such as steel and chemical industry to provide high energy consumption equipment

3. Newenergyaccess

Boost stations of wind farms and photovoltaic power stations to connect new energy power to the main grid

4. Urban grid construction

The core substation of the metropolitan area, ensuring the reliability of the city's power supply

1. Core systems

High magnetic permeability cold rolled oriented silicon steel sheet

The main magnetic circuit and the mechanical skeleton that make up the transformer

Laser processing ensures burr ≤0.03 mm

2. Winding structure

High voltage windings and low voltage windings with copper wire or foil

Cable paper is used for inter-turn insulation, and cooling oil passages are provided between layers

Longitudinal and primary insulation work together to ensure electrical safety

3. Fuel Tanks & Cooling System

Fully sealed corrugated sheet fuel tank structure, beautiful and practical

The cooling unit dissipates the running heat by means of heat exchange

Forced oil circulation cooling meets large capacity requirements

4. Protective devices

Gas relays: signal or trip in case of internal failure

Pressure release valve: directional injection to prevent the tank from bursting

Moisture absorber: absorbs moisture that enters the air in the oil pillow

Oil storage tank: adjust the oil volume change to prevent oil aging

 

5. Measurement & Control

Signal thermometers monitor operating temperatures in real time

The oil level gauge shows the oil level status

Tap switch for fine voltage regulation

Kechang Electric's 220kV oil-immersed transformer adopts a number of patented technologies:

• The high and low pressure clamps are fastened with steel tension straps to form a solid frame
• The coil is provided with a longitudinal oil passage, which greatly reduces the copper oil temperature difference
• Passed ISO9001 quality management system certification
• It has 56 national patents, ensuring technological leadership

As the key equipment of the power system, the 220 kV oil-immersed power transformer provides efficient escort in terms of high efficiency, energy saving, reliability and durability, and plays an irreplaceable role in power grid construction and power development. With its advanced production technology and strict quality control, Kechang Electric provides customers with transformer products with excellent performance and stable operation, providing a solid guarantee for the safe and efficient transmission of power energy.