Mitigation of overvoltage in LVDC distribution system with constant power load using generic energy storage system

The operation of a high-speed DC circuit breaker can cause overvoltage transients in the Low Voltage Direct Current (LVDC) distribution system, especially when driving a constant power load (CPL). Without adequate damping, the destabilizing effect of the CPL can push the system towards instability. This paper proposes a novel approach to mitigate over-voltage transients caused by DC circuit breaker operation in the LVDC system using a generic energy storage system (GESS). The paper begins by introducing the concept, modeling, coordinated operation and practical application of GESS. GESS employs both power-centric storage, such as supercapacitors, to limit the switching over-voltage within safe limits, and energy-centric storage, such as batteries, to ensure the energy sustainability. A state-space model of a detailed LVDC distribution system with CPL and GESS is subsequently developed. Additionally, to ensure system stability, analytical expressions are derived to determine the required sizing of the power-centric storage under different case scenarios. Simulation analysis using MATLAB's Control System Toolbox validates that GESS can stabilize voltage transients and reduce overshoots within 10 ms. Moreover, the proposed GESS solution is proven to be more reliable and cost-effective than supercapacitor and hybrid energy storage solutions. It is also scalable to larger LVDC networks and adaptable to different load scenarios.