Simulation of vertical power flow at MV/HV transformers for quantification of curtailed renewable power

Abstract

The progressing integration of renewables (RE) into distribution grids leads to bidirectional power flows. Due to the fact that the power infeed by RE exceeds the grid capacities, bottlenecks occur increasingly and thereby renewable power generation has to be curtailed. For the decision if countermeasures like flexibility options could be applied, the knowledge of the amount of curtailed power as well as its local and temporal availability is crucial. This study proposes an approach to determine the curtailed power characteristics, which creates time series simulating the potential vertical power flow at medium voltage/ high voltage (MV/HV) transformers without curtailment. The approach is thereby modular and adjustable to the investigated (or any other) grid, so it achieves a high precision. The power flow at these transformers is modelled by load profiles and power curves of connected RE, which are adjusted individually for each transformer on the basis of the corresponding historical power flow. For validation, the transformers are clustered corresponding to their power flow characteristics and the uncertainty is determined for each cluster. Modelled wind power shows a mean deviation below 2% of total installed wind power. Thereby, the presented modelling approach is able to determine the curtailed power in regions with wind power-related curtailments.