Grid Load Mitigation in EV Fast Charging Stations Through Integration of a High-Performance Flywheel Energy Storage System with CFRP Rotor

Increasing the share of battery electric mobility in the transport mix, while at the same time integrating more renewable volatile energy sources in the grid, brings along a variety of challenges such as possible power quality, voltage and grid stability issues. Deploying decentralized energy storage devices in electric vehicle (EV) fast charging stations as buffer storage is one way to mitigate these problems and help store renewable energy in the grid. This paper describes a system integrating a high performance flywheel energy storage system (FESS) in a fully automated fast charging station. A holistic approach is pursued, determining the FESS’s energetic target properties by analyzing user behavior in a variety of use cases in conjunction with in-depth grid simulations. Based on these data, a FESS design is proposed and approaches to reach the desired energetic target properties are discussed. Critical components are presented with a focus on CFRP rotor design, as it is crucial for achieving the required energy content at lowest specific cost.