S13(22)-MD Underground Transformer

Product Overview

An underground transformer is a distribution transformer or combined transformer that can be installed in an underground pit. It is a compact integrated distribution facility that integrates the transformer, high-voltage load switch, protective fuse and other components into an oil tank. Reference Standard: JB/T 10544-2006.

Underground transformers are applicable to high-voltage power transmission systems with long distance and light load such as roads, bridges and tunnels, combined transformers for overhead line underground projects, and residential area power supply systems. They are widely used in three-phase 50Hz underground power transmission and distribution networks with a voltage class of 10kV and below that require high power supply reliability and have no impact on the surrounding environment, providing power distribution and lighting for urban arterial roads, airports, bridges, tunnels, large green spaces, parks and other places.

The prefabricated underground transformer compact substation is composed of an underground transformer, an advertising light box type switch cabinet and a prefabricated underground pit. It is a complete set of equipment pre-assembled in the factory and qualified by ex-factory tests. The product consists of two parts of equipment: below the ground surface and above the ground surface. The part below the ground surface includes a prefabricated (or cast-in-situ concrete) underground pit and an underground transformer; the part above the ground surface includes an advertising light box type (or traditional) outdoor switchgear and a ventilation and heat dissipation channel. This product is suitable for various urban power distribution systems, especially for power supporting projects in municipal construction such as cable underground transformation.

The landscape-type underground compact substation is independently developed and produced by the company. It is a new type of transformer composed of an underground combined transformer, outdoor high and low-voltage cabinets, a light box type protective shell and a prefabricated underground transformer foundation. The transformer can also be customized to match the surrounding environment according to environmental characteristics, further integrating into and beautifying the environment.

Product Features

Small floor area, no occupation of ground surface area, excellent landscape effect and simple construction.

Realize the installation close to the load center and decentralized power supply mode, save the quantity and investment of low-voltage cables, reduce line losses, and achieve economical operation.

Protection class IP68, explosion-proof, and capable of fully submerged operation for a certain period of time, effectively improving the reliability of the power supply system.

The oil tank adopts a fully insulated, fully sealed and fully welded structure, which can withstand a pressure of 70kPa without oil leakage or deformation, effectively improving the comprehensive mechanical properties of the oil tank; no insulation distance is required, reliably ensuring personal safety; a unique heat sink is adopted to ensure the mechanical strength and heat dissipation capacity of the heat sink.

The connection of high and low-voltage cables can be realized in the following ways:

Adopt three-phase cable connectors with three phases inserted into the transformer at the same time and special cable plug connectors (suitable for three-phase underground transformers with a voltage class of 10kV and below and a capacity of 400kVA and below).

Adopt single-phase cable connectors and elbow-type plug-in cable connectors (suitable for three-phase underground transformers with a voltage class of 10kV and below and a capacity of 1600kVA and below).

The connector is filled with patented insulating liquid with a higher specific gravity than water, and the insulating liquid in the connector is separated from the transformer oil, ensuring normal operation in case of water seepage caused by capillary phenomenon.

An oil-immersed load switch can be configured to realize on-load breaking and closing operations; realize ring network and terminal power supply modes with very convenient conversion, improving the reliability of power supply.

The light box type switch cabinet of the prefabricated underground transformer compact substation features simple installation and an advanced display effect. In addition, the media advertising on the advertising light box can create good economic benefits.

The prefabricated underground transformer compact substation adopts natural ventilation, and the overall temperature rise is designed with the transformer, underground pit and light box as a whole. The temperature rise value of the transformer operating at rated load in the underground pit meets the requirements of GB1094.2.

An automatic drainage system can be installed in the underground pit, which will automatically start the drainage device in case of special situations such as floods.