How should an overload be alleviated if a transformer is loaded to 150% of its capacity and only one other transformer is at 90%?

Shed load is the most appropriate action when a transformer is overloaded, especially in this scenario where one transformer is operating at 150% of its capacity. This situation poses a risk to the transformer's integrity, leading to overheating and potential failure, which could result in significant downtime and costly repairs. By shedding load, the demand on the overloaded transformer is reduced, allowing it to operate within safe limits and preventing damage.

This action effectively balances the load by either temporarily disconnecting certain non-essential loads or redistributing the load among the available transformers to ensure that no single unit exceeds its rated capacity. Additionally, shedding load is often a quicker response to an overload situation, as it can be implemented immediately without the need for adjustments or changes in infrastructure.

Other measures, like adjusting the tap changer on the transformer at 90%, might help regulate voltage but would not directly alleviate the overload condition on the 150% transformer. Similarly, raising transmission voltage could have various effects on the system, but it is not a direct solution to the overload. Removing the overloaded transformer from service could be a last resort due to the interruption it causes to the system, potentially leading to service disruption before any alternative solutions are employed. Therefore, shedding load is the most efficient and immediate way