transformer：S11-DM series underground Liquid Filled Transformers

Product Introduction

Underground transformer: A distribution transformer or combined transformer that can be installed in the pit. Generally installed in the pit, it does not occupy the effective space on the surface, does not affect the visual effect, makes the power supply equipment and the surrounding environment harmonious, and can avoid unintentional or intentional damage from the outside world, and the impact on the surrounding environment and personnel of the equipment can also be reduced to a minimum.

With the deepening of urban development and urban power grid transformation, safe, reliable and underground transformers that do not occupy surface space are gradually being used in road lighting, residential electricity, airports, city squares, highways, bridges, tunnels, etc. in central urban areas.

Product features:

1. Suitable for urban environment (installed in basements or cellars), especially suitable for densely populated central cities; 2. Lighting and power system suitable for streets, highways, bridges, tunnels, parking lots, airports, ports, tourist attractions, etc.: 3. The high and low voltage inlet and outlet lines adopt waterproof and fully sealed, fully insulated and fully shielded wiring methods;

4. The shell of the box is made of anti-corrosion steel plate or stainless steel, fully sealed, and can be immersed in water for a period of time; 5. The protection system fully considers the convenience and safety of operation, and the accessories are made of American COOPER company or domestic high-quality products with the same performance; 6. The operation rod is used to operate the underground transformer, which has the same operation mode as the combined transformer;

7. Fully considering the particularity of heat dissipation conditions, the transformer adopts low loss and low temperature design; 8. Waterproof entry protection and automatic drainage measures are installed in the transformer cellar.

Product structure

Underground transformers are generally installed in pits constructed with concrete, which does not occupy surface space, and high-voltage casing wells and low-voltage ends are installed on underground transformers and box covers

fuses, plug-in arresters, pressure release valves, these accessories can be observed and operated on the ground.

The tank is made of stainless steel (or using high-quality steel plate multi-layer anti-corrosion technical measures), the fully sealed structure and the box along the closed welded structure to minimize the sealing area, which can be used in

Long-term safe operation in the special environment of the ground.

The integrated control device of the underground combi transformer can send communication signals to the outside world via RS485, wired Mloden, wireless GSM, or wireless GPRS. If you use none

When the line GPRS sends communication signals to the outside world, users only need to log in to the designated website to monitor the parameters of the transformer operation in real time.

Waterproofing measures for underground transformers

1. Waterproof considerations during basic design and production

Top: Ventilation holes have effective rainproof and waterproof capabilities;

Side: The surface treatment on the opposite side of the surface is made of waterproof concrete material, so that water seepage cannot enter from the side of the pit

Bottom: The waterproof concrete load-bearing base for installing the underground transformer is 300mm higher than the bottom of the pit, and the water that usually flows from the ground to the pit flows into a ring below the base

On the road, it will not be soaked into the underground transformer.

2. The bottom of the foundation is laid with water-free sand pebbles, and the water can penetrate the ground relatively quickly.

3. The underground transformer is allowed to operate below 0.5m in water for a certain period of time, which can resist flood disasters and effectively improve the reliability of the power supply system. But for underground transformers

It is recommended to check the water accumulation in the pit after floods, long periods of heavy rain and the rainy season.

Measures for the control of temperature rise of underground transformers

For the temperature rise control of underground transformers, it can be guaranteed by the following four aspects:

1. The low temperature rise design of the transformer, the top oil temperature is controlled at about 45K, which is far lower than the 60K stipulated by the national standard, and the design idea is:

1. The heat load is directly proportional to the loss, and the raw materials used in the underground transformer designed and produced by our company are low-loss products, compared with GB6451-1999.

30% lower no-load loss and 15% lower load loss; Compared to the 9 series, the no-load hanger consumption is 20% lower, so the heat load is low.

2. Naphthenic alkyl transformer oil is used, which can make the oil medium flow freely at extremely low temperature without adding additives, and its good viscosity-time characteristics make it rise at temperature

At high speeds, the flow of oil is accelerated, ensuring that the product has good heat dissipation capacity.

2. Box structure

The heat dissipation of the tank wall of an underground transformer mainly depends on radiation. The heat is always radiated in the form of waves from the heating element to the surrounding medium with a lower temperature. The energy of radiation depends on the temperature

degree, the shape of the heating element and its surface color. Therefore, underground transformers use flat fuel tanks and flat heat sinks to enhance radiation.

3. Surface treatment;

Because the underground transformer body is installed under the cool surface, a special surface surface treatment process is used to ensure that it has good heat radiation ability and strong corrosion resistance

Ability.

4. Basic production

The heat dissipation between the foundation and the outside world depends on heat conduction and air convection, and ventilation openings and air deflectors can be set up on the top of the foundation to enhance air circulation.

Performance parameters