Medium-term impact of daily heat pump load profiles to forecast congestion of distribution network assets

George Rouwhorst, Phuong H. Nguyen, Han Slootweg

Abstract: The rapid increase of residential heat pumps (HPs) being installed has a major impact on the required capacity of distribution networks. To avoid congestion of assets, an efficient reinforcement strategy is required that can calculate the impact of residential HPs and identify assets at risk of congestion. Therefore, this paper proposes a methodology that indicates the influence of intra-annual variation on the impact of distribution network assets and calculates the frequency, power, and duration of congestion events. First, this paper proposes a methodology to calculate daily aggregated electric load profiles (AELPs) with an hourly resolution and an annual time horizon of 36 residential HPs. Second, the daily AELPs were aggregated with a medium to low voltage (MV/LV) transformer loading. The annual normalized root mean square error (NRMSE) of the MV/LV transformer with the HPs of the training set was 8.4%. The accuracy was verified with 20 other residential HPs where the annual NRMSE was 5.7%. Finally, the accuracy of the calculated frequency, power, and duration of the congestion events from the HPs of the test set was analyzed per month.