Transferring Curative System Operation Principles to Distribution Systems: Practical Insights into Opportunities and Challenges

The transformation of the energy system towards climate neutrality with a high share of renewable energy sources requires more efficient dimensioning and operating principles, particularly at the 110 kV level of distribution grids in which dis-tributed energies are integrated. Curative operation principles increase the transmission capacity of the grid, serving as an additional strategy alongside expansion measures to achieve necessary capacity increases and system stability. In addition, operators of distributed energy system can benefit from quicker grid connections or reduce the connection cost-to-power ratio if curative measures reduce the need for extensive grid reinforcement. Implementing curative operation principles in the distribution grid still faces multiple challenges. Structural differences between transmission and distribution grids need to be considered. Higher utilization of assets at the 110 kV level raises questions about stability-related constraints. Appropriate financial compensation strategies that consider positive effects on system operation and dimensioning, scaling with power and availability in various time spans, and considering requirements of energy-related market issues need to be developed. This publication provides a practically relevant overview of the opportunities and challenges associated with transferring curative system operation principles to 110 kV distribution systems, which includes an overview of the curative system operation principle and the motivation for participating in it (for grid operators and customers). Structural differences between the transmission as well as distribution system are also covered and aspects related to system stability and market issues are considered providing a thorough understanding of the aforementioned opportunities and challenges.