Battery Energy Storage System Shedding for Power System Emergency Stability Control

Recently, renewable energy sources (e.g, solar energy, and wind energy) have become an increasingly important part of the power system, and the reliability and stability of the power supply in the system are being challenged. However, increasing renewable energy in the power grid will meet uncertain factors, such as reduction of system inertia and alteration of system dynamic characteristics, severely affecting power system stability when a disturbance with significant severity occurs, such as generator tripping and disconnection of transmission lines. Thus, this thesis will focus on effective and efficient controlling of BESS to enhance power system stability in an emergency state. This thesis firstly proposes the BESS shedding as a new approach for power systems EEC. The BESS load shedding would be a more cost-effective method for the EEC compared to traditional load shedding, considering that the connection between the electrical system and the BESS is controlled by a relay in the battery management system, which has a negligible control cost examines the feasibility analysis of a BESS under the state of charge being shed in the emergency control of a power system, Therefore, the article analyses the feasibility of BESS shedding in the charging state in emergency control of the power system, which is implemented on the New England 10 machine 39 bus system, which compares the ability of the system with and without BESS to recover its stability at different fault locations. The sensitivity analysis method is proposed secondly, based on the trajectory obtained from the dynamic simulation of the power system for comparative analysis, the method of sensitivity trajectory analysis is used, which is easy to implement and simple to calculate. This thesis proposes a hierarchical event-driven emergency control method for event-driven emergency control (EEC) of power systems and a hierarchical control method that considers the control cost of the deviation between different types of control actions (including BESS charging and discharging control, load shedding). The proposed method is validated by testing on a benchmark power network with extensive renewable energy sources and BESS for event-driven emergency control. The proposed method has been successfully presented in comparison with conventional emergency control methods