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.

Forecast of Renewable Curtailment in Distribution Grids Considering Uncertainties

“…The node injections are calculated corresponding to our previous work [17]. The applied load profiles and functions describing the RE generation are adjusted individually to each node.…”

“…The specific injection of each node connected to MV/HV transformers are represented by the model for the vertical power flow on MV/HV transformers according to our previous paper [17] visualized in Fig. 2.…”

“…For WP modeling it is chosen between the approaches WP and DM for each transformer specifically. In order to fit a transformer specific 24 h load profile different type of days and seasons are considered, more details can be found in [17].…”

“…This could be a valuable information for optimizing curtailment by applying flexibility options [16]. The model is designed to be individually adaptable to a specific grid, by adjusting nodes of the high voltage (HV) level to their specific in-feed and consumption applying our previous work proposed in [17]. Therefore historic power flow data of medium voltage/high voltage (MV/HV) transformers and the grid topology provided by corresponding system operators are applied.…”

Low Working Temperature of ZnO-MoS2 Nanocomposites for Delaying Aging with Good Acetylene Gas-Sensing Properties

“…At present, oil-immersed power transformers are mainly popular in China [ 4 , 5 ]. Hydrocarbons in the insulating oil will decompose following thermal or electrical failure, causing the C–H bond and C–C bond breaking and forming gas molecules [ 6 , 7 , 8 , 9 ]. Therefore, dissolved gas analysis (DGA), as a diagnostic method for potential faults, is effective in oil-immersed power transformers.…”