Average model of the ESS. In this model, the whole power converter interface of the energy storage unit is replaced by ideal voltage sources, which reproduce the averaged behavior of the VSC legs during the switching interval.
Simplification of energy storage mathematical models is common to reduce the order of the equivalent ECM circuits, or to completely idealize them both with and without taking into account the SOC dependence.
It should be noted that by analogy with the BESS model, the SC, FC and SMES models can be implemented considering their charging and discharging characteristics. In addition, by applying a similar approach to the design of the energy storage model itself, they can be implemented in any other positive-sequence time domain simulation tools.
Part i☆ Energy storage systems are increasingly used as part of electric power systems to solve various problems of power supply reliability. With increasing power of the energy storage systems and the share of their use in electric power systems, their influence on operation modes and transient processes becomes significant.
Reduced-order Model of ESS: KESS and TESS are the gain and time constant of the energy storage, PESS and QESS are the output active and reactive power of the energy storage. By varying the time constant, the type of energy storage and power converter are reproduced.
In such cases, the detailed reproduction of the processes in the energy storage is usually not investigated, and the modeling tasks are to study the dynamic response of the complex energy storage model in emergency modes, including studies of the frequency and voltage support in the ECM by means of the ESS.