[UC38] Transformer Load Increase Assessment Tool

A transformer load refers to the amount of power drawn by the electrical load connected to a transformer. For grid operators, it is important to ensure that a transformer is not overloaded, as this can damage the transformer and potentially lead to power outages or other issues. Overheating and, consequently, reduced transformer lifespan are some of the consequences of an overloaded transformer.

With an increasing number of new connection requests in the distribution grid, such as businesses, households, EV chargers, heat pumps, etc., it is important to have a capacity management plan in place to ensure that the distribution grid and the transformers within it can accommodate the new connections without compromising the reliability and quality of service for existing customers. It is, therefore, necessary to assess the load changes for these new connection requests.

Grid operators traditionally use approximate load or load calculated from the reserved capacity (Master Circuit Breaker value) for estimating the transformer load of connected customers. With both approaches, this calculation will not take into account reality. Still, it will only be an estimate, which is also likely very inaccurate because the calculation will not include real measured data. To make matters worse, in the majority of the cases, there is no measurement at the transformer; only individual meters “behind” the transformer are measured.

For these reasons, aggregating the transformer downstream load is necessary to model the transformer loading and consequently increase the transformer’s expected loading for the new connection request load. This process will ensure that grid operators can make educated decisions about allowing new connections into the grid.