European Prefabricated Substation Structure and Design
Scientific Overall Layout
The internal structure of the European-style prefabricated substation enclosure mainly consists of a high-voltage compartment, a transformer compartment, and a low-voltage distribution compartment. It has various combination installation methods, commonly including integrated and combined types. The combined installation method places the three parts in their respective compartments. Currently, common combined structures often use a straight or L-shaped layout, which is compact, convenient for wiring, and provides sufficient maintenance access for later maintenance. The integrated layout uses the transformer as the main body, with fuses and load switches installed inside the transformer enclosure for auxiliary operation, resulting in a more compact structure.
Durable Enclosure Design and Material Options
The European-style prefabricated substation enclosure is meticulously constructed from three parts: a base, an outer shell, and a top cover. The base is typically made of high-quality steel materials such as channel steel, angle steel, flat steel, and steel plates, assembled and fixed through welding or bolting to ensure the overall structural stability. To meet ventilation, heat dissipation, and incoming/outgoing line needs, slotted and appropriately sized circular holes are provided at appropriate locations, reflecting a human-centered design philosophy. The exterior design can be customized in color and shape according to the installation environment and customer requirements to ensure harmony with the surrounding environment.
Comprehensive Protection and Cooling System
European-style prefabricated substations possess excellent environmental protection capabilities, meeting requirements for rainproofing, dustproofing, corrosion resistance, and animal intrusion prevention. To prevent strong solar radiation in hot summers, the top is generally filled with insulation materials with low thermal conductivity, commonly including rock wool boards and polystyrene foam.
In terms of heat dissipation design, modern European-style prefabricated substations employ a comprehensive heat dissipation solution. In addition to retaining the method of punching louvers on the shell, methods such as increasing the heat dissipation area and enhancing air convection are also used for heat dissipation. This method not only effectively improves heat dissipation efficiency but also reduces manufacturing costs, demonstrating a perfect combination of economy and practicality.
European Prefabricated Substation Electrical Design
Structure of High-Voltage Distribution Equipment
European-style prefabricated substations’ high-voltage distribution equipment is divided into two types based on the incoming line method: terminal type and ring network type; based on the incoming line location, it can be divided into overhead line entry from the top of the enclosure (commonly used in traditional prefabricated substations) and underground line entry and exit via high-voltage cable trenches, which is a more common method in modern design.
Regarding the selection of switchgear, SF6 series load switches using SF6 gas as the arc-extinguishing medium are currently widely used, although their cost is higher than that of FN-10 series high-voltage load switches. These switches are available with or without fuses, and with grounding switches, but generally, all are equipped with live indicators to ensure operational safety. The operating mechanism is generally manual, but electric operation is also available to meet different user needs. Switches with fuses can automatically disconnect the switch when a short-circuit fault occurs in the circuit, effectively protecting the circuit and equipment such as transformers and switches.
The high-voltage metering system is configured according to user needs. The high-voltage metering cabinet typically consists of a CT, PT, metering instruments, remote control, and telemetry devices.
Professional Transformer Room Design
European-style prefabricated substations have independent transformer rooms, which mainly consist of transformers, automatic temperature control systems, lighting, and safety railings. Heat dissipation and ventilation in the transformer room are key considerations in the design of European-style prefabricated substations, especially given the large amount of heat generated during transformer operation and the rapid temperature rise in high ambient temperatures.
To address heat dissipation, European-style prefabricated substations are designed with a comprehensive temperature control system. Except for substations with smaller transformer capacities that use natural ventilation, most systems incorporate temperature protection and forced ventilation. This system mainly consists of measuring devices (capable of measuring both transformer room temperature and oil temperature) that, through manual and automatic control circuits, control whether the exhaust fan needs to be activated, setting the temperature range for reliable and safe transformer operation to ensure the transformer always operates at a suitable temperature.
Regarding transformer selection, European-style prefabricated substations can use either oil-immersed or dry-type transformers. From an economic perspective, due to the higher price of dry-type transformers, oil-immersed transformers should be the preferred choice to reduce manufacturing costs unless otherwise specified by the user. Transformer capacity configuration is generally suitable between 100-1250KVA, and should not exceed 1600KVA. This capacity range can meet the needs of most application scenarios.
Flexible Low-Voltage Room Structural Design
The low-voltage room design of European-style prefabricated substations fully considers the special needs of different usage scenarios. For European-style prefabricated substations used in industrial and mining enterprises, power supply and lighting supply should be designed separately. When using low-voltage metering, power supply bureaus usually require separate metering for lighting electricity, mainly because the unit price of lighting electricity is generally higher than that of power electricity. However, for substations used in residential areas, the structural design does not need to consider power supply issues, reflecting a human-centered design.
In terms of output circuit design, the low-voltage room of European-style substations is flexibly configured according to the transformer capacity and user needs. When the transformer capacity is small and the user requires fewer output channels, the number of channels can be reduced; conversely, when the transformer capacity is large and the user requires a large number of input/output channels, the number of channels can be increased. A layout with corridor operation can also be adopted to demonstrate design flexibility.
European vs. American Prefabricated Substations
| European Compact Substation | American Compact Substation | |
| Structure | Compartmentalized layout (HV, transformer, LV sections separated) | Integrated tank design (all components in one enclosure) |
| Installation | Typically outdoor, suitable for public or industrial power distribution | Usually pad-mounted, used in urban or residential areas |
| Insulation Medium | Air, SF₆, or solid insulation | Mineral oil or silicone oil |
| Appearance | Metal-enclosed structure with customizable design | Compact rectangular steel tank |
| Maintenance | Easy inspection and replacement of each section | Requires a complete power-off for maintenance |
| Application | Ideal for urban, commercial, and industrial distribution networks | Preferred for residential, utility, and suburban networks |
Technical Advantages of European Prefabricated Substations
European-style prefabricated substations, with their scientific structural design, reliable material selection, and complete electrical system, demonstrate significant advantages in the power distribution field. Its compartmentalized, independent structure ensures the relative independence of each functional area, facilitating maintenance and enhancing safety; diverse material choices meet the needs of different environmental conditions; a comprehensive heat dissipation system guarantees long-term stable operation; and a flexible low-voltage compartment design adapts to various application scenarios. These features make European-style prefabricated substations an indispensable component of modern power distribution systems, providing a reliable power supply. With continuous technological advancements, European-style prefabricated substations will continue to be optimized and innovated, making greater contributions to the development of the power industry.
