With the rapid growth of electric vehicle (EV) charging infrastructure worldwide, especially high-power charging stations, heavy-duty truck charging hubs, and integrated solar-storage-charging projects, the reliability of power supply has become a key factor affecting project operation and profitability.

Selecting the right type of box-type substation (prefabricated substation) is critical. Among different solutions, Ring Main Unit (RMU) Type Box Substation and Terminal Type Box Substation are two common choices. Understanding their differences helps project owners, EPC companies, and electrical contractors select the most suitable power distribution solution.

Ring Main Unit Box Substation: Ensuring Reliable Power Supply for Large Charging InfrastructureA Ring Main Unit (RMU) Type Box Substation adopts a one-in-one-out power supply structure, allowing multiple substations to be connected in a ring network along the same power distribution line.

This design provides several important advantages:

1. Continuous Power Supply and Fault Isolation

When a fault occurs or maintenance is required on a section of the power grid, the ring network system can automatically isolate the fault point while maintaining power supply to other sections.

For large EV charging stations, this means:

• Avoiding complete station shutdown

• Reducing downtime losses

• Protecting charging service revenue

• Improving overall system reliability

For highway heavy-duty truck charging stations, large-scale EV charging hubs, and solar-storage-charging integrated projects, RMU box substations are usually the preferred choice.

Terminal Type Box Substation: Cost-Effective Solution for Small Charging Projects

A Terminal Type Box Substation uses a single incoming power line structure and is mainly installed at the end of a distribution network.

Compared with RMU type substations, terminal substations have a simpler structure and lower investment cost.

Key Advantages:

• Lower equipment cost

• Easier installation

• Simple operation and maintenance

• Suitable for small-scale applications

In general, terminal-type box substations can reduce project investment by approximately 20%-35% compared with ring network solutions.

They are ideal for:

• Small charging stations

• Community charging projects

• Rural charging facilities

• Low-load demonstration projects

Three Key Recommendations for Selecting the Right Box Substation

1. Choose RMU Box Substation for Ring Network Planning

If the local power utility has planned a ring network corridor, or multiple charging stations need to be connected together in the same area, an RMU type box substation is the recommended solution.

It provides:

✔ Higher power supply reliability
✔ Better network flexibility
✔ Easier future expansion

2. Choose RMU Box Substation for High-Value Charging Stations

For:

• Heavy-duty truck fast charging stations

• High-power charging hubs

• Energy storage integrated charging stations

• Commercial projects with high revenue requirements

Reliability is more important than initial investment.

Choosing an RMU box substation can effectively reduce operational risks and prevent revenue losses caused by power interruptions.

3. Choose Terminal Box Substation for Small and Cost-Sensitive Projects

For single-point charging stations with limited charging demand, where investment control is the priority, a terminal-type box substation provides the best cost-performance ratio.

It is a practical choice for:

✔ Small charging operators
✔ Community charging facilities
✔ Distributed charging pilot projects

Beike Electric Provides Customized Box Substation Solutions for Global Energy Projects

As the demand for EV charging infrastructure continues to grow, selecting the right power distribution equipment becomes increasingly important.

Shanxi Beike Electric provides customized box-type substation solutions for EV charging stations, renewable energy projects, industrial facilities, and power distribution networks.

With advanced manufacturing capabilities, strict quality control systems, and professional engineering experience, Beike Electric delivers reliable and efficient power solutions for global customers.

From design consultation and equipment manufacturing to installation guidance and after-sales service, we provide a complete one-stop electrical solution.

For your next EV charging infrastructure project, contact Beike Electric for a customized power distribution solution.