YBD-12 Underground substation

The YBD-12 Underground substation is a new product from Weisho Electric Co., Ltd., designed with flood/waterlogging resistance. It takes up only 30% of the space of traditional pad-mounted substations (nearly no above-ground footprint) and features low noise and electromagnetic radiation. As traditional pad-mounted substations—common in downtowns, residential complexes, and industrial parks—waste prime urban land and ruin landscapes, the rise of urban construction has driven the development of this landscape-friendly buried version to meet modern aesthetic and space needs.

Composed of an underground combined transformer (buried transformer), fully insulated/sealed compact high-voltage switchgear, outdoor high- and low-voltage switchgear, and a light box-style low-voltage enclosure, this pre-assembled underground power equipment can also include optional light box-style cable distribution boxes or high-voltage metering, as requested by the user. It replaces traditional civil construction, as well as European- and American-style substations, for power transformation and distribution. Its core design houses key components in a patented waterproof compartment: vents enable heat dissipation normally, while full sealing prevents water ingress during floods. The compact buried transformer (integrating transformers, high-voltage load switches, etc.) works even submerged for a period, delivering strong economic and social benefits.

An underground substation is an electrical facility that fully embeds traditional pad-mounted substations below ground level, falling under the field of electrical engineering technology. Its design addresses the challenge of site selection for above-ground substations caused by limited land resources, while also eliminating the visual inconsistency of conventional pad-mounted substations in European and American urban landscapes.

European and American countries have gradually developed mature technologies for underground substations, which now serve as the primary solution for 10kVA power distribution in cities like New York and Chicago. Manufactured using fully sealed, environmentally friendly materials, this facility offers corrosion resistance, water resistance, and pressure resistance, with an ingress protection rating of IP68—enabling long-term operation even when submerged in water.

Equipped with automatic temperature control, drainage, and humidity control functions, the above-ground area of the underground substation can be converted into green belts or parking lots. This not only saves land but also reduces infrastructure costs.

Normal Operating Conditions

a) Altitude: Not exceeding 1,000 meters above sea level.

b) Ambient Temperature: Maximum temperature of +40°C; minimum temperature of -30°C.

c) Relative Humidity: At 25°C, the relative air humidity shall not exceed 95%, and the monthly average shall not exceed 90%.

d) Installation Environment: The installation site shall be free from obvious pollution, explosive or corrosive gases, and dust. It shall also be free from severe vibration or impact, and shall not be installed in low-lying areas (prone to water accumulation).

Structural Features

All components of the fully buried prefabricated substation are housed in a fully sealed enclosure, split into three compartments: high-voltage switchgear, transformer, and low-voltage switchgear. Each compartment includes lighting, interlocking switches, forced ventilation, temperature controls, heaters, and other support equipment.

Installed entirely below ground, the substation uses the same internal components as conventional above-ground models: it takes 10kV input, steps it down to 400/220V via the transformer, and distributes power to loads. Its key technologies focus on the enclosure’s sealing, corrosion resistance, and pressure resistance:

No corrosion on the enclosure (from bottom to walls) after 50 years of underground immersion.

Withstands soil and groundwater pressure/seepage without wall damage.

Sealed points (equipment access, personnel entrances, cable entries) resist groundwater seepage, keeping the interior dry and free of water stains.

Beyond these basics, the YBDM model adds three core functions:

Two water collection troughs on the enclosure’s narrow end quickly drain rainwater to sewers, preventing interior entry.

Troughs double as air inlets for internal ventilation: air exchange balances temperature/humidity and lowers transformer heat.

For once-in-50/100-year floods (groundwater rise causes sewer backflow), the ventilation system auto-shuts to isolate the enclosure—equipment remains unaffected, and the substation operates normally.