35kV with double busbar connection

Yes, a 35kV system can use a double busbar configuration, providing enhanced reliability, operational flexibility, and maintenance without load interruption.

Feasibility and Typical Use

Double busbar (DBB) arrangements are commonly applied in medium-voltage (MV) systems ranging from 6.6kV to 36kV, which includes 35kV installations . In a DBB setup, two independent busbars—often called Bus A and Bus B—run in parallel, and each feeder or transformer can be connected to either bus via selector disconnectors. A bus coupler links the two buses, allowing load transfer without interrupting supply .

Advantages

1. High Reliability: If one bus experiences a fault or requires maintenance, the other bus can continue supplying power, minimizing downtime .
2. Operational Flexibility: Load can be transferred between buses, and circuits can be isolated for inspection, extension, or repair without interrupting service .
3. Maintenance Without Outage: Critical facilities, such as industrial plants, substations, or hospitals, benefit from uninterrupted operation during bus maintenance or breaker replacement .
4. Fault Tolerance: A fault on one bus only affects the circuits connected to it, while the remaining circuits stay energized via the healthy bus .

Considerations

• Cost and Complexity: DBB systems require more equipment, including additional breakers, disconnectors, and interlocking, which increases installation and maintenance costs .
• Space Requirements: The physical footprint is larger than a single busbar system, which must be considered in substation design .
• Protection Coordination: Proper bus differential protection and breaker failure logic are essential to ensure safe and reliable operation during bus transfer or fault conditions .

Applications

Double busbar configurations are typically used in:

• Utility distribution substations where supply continuity is critical.
• Industrial plants with high-value or continuous processes.
• Critical infrastructure such as airports, data centers, and hospitals .

Conclusion

A 35kV system can effectively implement a double busbar arrangement, especially where high reliability, operational flexibility, and uninterrupted maintenance are required. While the initial cost and complexity are higher than single busbar systems, the benefits in critical applications often justify the investment. Proper design, protection, and operational procedures are essential to maximize the advantages of a DBB system.