Modelling battery energy storage systems for active network management—coordinated control design and validation

Abstract

Control of battery energy storage systems (BESS) for active network management (ANM) should be done in coordinated way considering management of different BESS components like battery cells and inverter interface concurrently. In this paper, a detailed and accurate lithium-ion battery model has been used to design BESS controls, thereby allowing improved overall power system control design optimisation studies by simultaneously considering both component and system-level aspects. This model is utilised to develop a multi-objective ANM scheme (a) to enhance utilisation of wind power generation locally by means of active power (P)-control of BESSs; (b) to utilise distributed energy resources (i.e. BESS and wind turbine generators) to maintain system voltage within the limits of grid code requirements by reactive power/voltage (QU)-and active power/voltage (PU)-controls. BESS control strategies to implement the ANM scheme, are designed and validated through real-time simulation in an existing smart grid pilot, Sundom Smart Grid (SSG), in Vaasa, Finland.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Aging aware adaptive control of Li-ion battery energy storage system for flexibility services provision

“…SOC is estimated by using coulomb counting method [29], which is shown in Eq. (7). SOC initial stands for the initial SOC of the cell, I cell (t), stands for cell current at time (t) and cell capacity refers to its maximum capacity in Ah.…”

“…Reactive power-voltage (QU)-control is one of the flexibility services which inverter-based DER can provide, in this study wind turbine generator (WTG) and Li-ion BESS. The limitation of active and reactive power contribution for both these inverter-based sources are explained in detail in [30]. The available reactive power support from WTG is defined as Q wind, av, and that of Li-ion BESS as Q BESS, av QU-droop has been designed for QU-control as shown in Fig.…”

“…In the developed ANM scheme, the role of Li-ion BESS active power dispatch is to enhance wind power generation and reactive power flexibilities from WTG and Li-ion BESS is to manage MV distribution system voltage. The simulation models for these studies are developed in ePhasorSim platform by OPAL-RT, details of which are explained in [30].…”

“…The power system model is based on the system parameters of the SSG provided by the local DSO and that of power generation details from WTG are based on the actual site data. The details of the power system model is similar to the previous studies undertaken by the authors [30,38], except the change in battery model which includes their aging characteristics and the Liion BESS controllers whose power outputs are governed by their aging aware PP capability. It has to be noted that in this simulation model services from the on-line tap changer (OLTC) transformer wasn't available, reason being to study management of flexibilities from available sources.…”

“…Recently, Li-ion battery energy storage systems (Li-ion BESSs) have become the forefront choice for utilization in land-based grid support applications, by acting as a FER which is capable of providing multiple flexibility services for ANM operations in the distribution system [7]. Nowadays, Li-ion BESSs are commercially available for large-scale for grid applications with power ratings in the range of hundreds of MWs.…”