Which station bus scheme is considered the most expensive and reliable for a power station?

The double bus, double breaker scheme is recognized as the most expensive and reliable station bus configuration for a power station due to its design that provides high levels of operational flexibility and redundancy. In this setup, there are two separate busbars and double breakers connecting each generator or load to both busbars.

This configuration allows for maintenance and operation flexibility since one bus can be taken out of service for maintenance while still allowing for the full operation of the power station through the second bus. The double breaker design further enhances reliability by providing multiple paths for electrical flow, which minimizes the chances of a complete outage during maintenance or fault conditions.

If a fault occurs, the double bus, double breaker arrangement can isolate the issue without impacting the entire system, ensuring continued power delivery and reliability. The increased cost of this scheme is attributed to the additional equipment and complexity involved, but the benefits of reliability and operational capability justify the investment, particularly for critical power plants.

Other configurations, while potentially less costly, do not offer the same level of reliability and operational flexibility that the double bus, double breaker scheme provides.