Dynamic modelling of battery energy storage system and application to power system stability

Abstract

Abstract: A useful and systematic dynamic model of a battery energy storage system (BES) is devel-oped for a large-scale power system stability study. The model takes into account converter equivalent circuits, battery characteristics and internal losses. Both charging mode and dis-charging mode are presented. The model is expressed in equivalent transfer function blocks, and it can be easily used in dynamic stability analysis of a power system. To examine the dynamic behaviour of the model, applications to the damping of turbogenerator torsional oscil-lations are performed. Active and reactive power modulation by the BES can be controlled accord-ing to system requirements. Eigenvalue analysis and dynamic simulations are performed to demonstrate the damping effect of the BES. List of principal symbols = ideal no-load maximum DC voltage of converter c = BES terminal voltage VBT R E T, R B S = battery connecting resistance and internal resistance X C O = converter commutating reactance I B E S, PEES, QBEs = BES current, active power, and react-Pm, QDC = DC active power and reactive power "B L = battery overvoltage R E 1 3 C B l ing and discharging procedures R B P = battery self-discharge resistance C B P = battery capacitance VB,, = battery open-circuit voltage