What is the primary consideration when planning the interconnected transmission system?

The primary consideration when planning the interconnected transmission system revolves around the reliability and stability of the system, particularly under expected operational conditions. The focus on the loss of one element is crucial because it allows planners to evaluate the resilience of the system to contingencies, such as the failure of a single transmission line, generator, or transformer.

By concentrating on the loss of one element, engineers can design the system such that alternative routes for power flow are available, ensuring that the remaining components can handle the load without causing cascading failures or significant disturbances. This approach aligns with the concepts of N-1 reliability standards, which mandate that the system should remain stable and operational even if one component fails.

Moreover, planning for the loss of one element helps establish an adequate level of redundancy and safeguards that enhance the overall security and efficiency of the power system. It ensures that the interconnected transmission network can maintain service continuity and reliability, which is paramount in providing a steady supply of electricity to consumers while minimizing the risk of widespread outages.