Review of Control Algorithms for Reconfigurable Battery Systems with an Industrial Example

Abstract

Battery cells within battery energy storage systems (BESS) do not have homogeneous attributes, and the lowest capacity ones limit the performance and lifetime of the whole pack. Modern battery management systems (BMS) solve this problem with balancing, while providing the required service, and safe operation to the user. Reconfigurable battery systems (RBS) are BESSs that involve a BMS with reconfiguration. Reconfiguration uses feedback to determine the circuit switching logic. This paper presents a structured review of the control algorithms for RBSs. The RBSs are divided into groups according to their control strategies and control implementations. Finding the adequate control strategy requires well-defined objectives and control design. The control implementation focuses on physical and architectural aspects, like the reconfiguration frequency, the balancing operation and the control topology. The considerations and categories are discussed with the advantages, disadvantages and academic examples, and then an innovative industrial BMS is introduced.

Reconfigurable battery systems: Challenges and safety solutions using intelligent system framework based on digital twins

“…To calculate the optimal topology of the system, it is necessary to establish the corresponding high-fidelity model to simulate all practicable circuit connections and the RBS performance. However, there is still no unified framework for the simulation of a reconfigurable battery system [2]. Generative adversarial networks is the commonly used data transmission method in existing systems.…”

“…This is actually achieved by deploying power switches around the cells and adjusting its connectivity in real time by using the dedicated micro-controller. To understand the state-of-the-art technology development in RBS and useful insights, the authors referred to several review studies [1][2][3]. These studies systematically introduce the various topology designs of RBS [earliest design, series topology and Self-X, genetic framework, 'dependable, efficient, scalable architecture' (DESA), directed acyclic graph etc.…”

“…To counter these, there is a strong need for industrial design of BMS integration in RBS for maximum reconfigurability, scalability, reliability and cost-effectiveness in real-time fashion with minimum hardware elements (contractors, relays, switches, circuit breakers and fuses), minimum computational (simpler and accurate estimation algorithms) burden and communication resources (Controller Area Network) etc. [2,5]. Though, some recent developments in RBS and its synergetic integrations with BMS are seen, the intelligent comprehensive framework in overcoming these challenges simultaneously is still not illustrated [1].…”

“…In recent years, Reconfigurable Battery Systems (RBS) is gaining emphasis owing to its advantages of adapting flexible topologies in series/parallel/hybrid during its operation based on the non-linear time-dependent load requirements and cell status [state of charge (SoC) and state of health (SoH)] [2]. This is actually achieved by deploying power switches around the cells and adjusting its connectivity in real time by using the dedicated micro-controller.…”

Efficiency Characteristic of a High-Power Reconfigurable Battery with Series-Connected Topology

“…The cells of this battery are equipped with semiconductor switches that can engage or bypass individual cells, achieving a reconfigurable topology [11]. Besides advanced cell balancing capabilities [10], this design allows to actively control the power flow to and from the battery by changing the total number of active cells. This could make power converters redundant in applications where batteries are directly coupled with other DC components, saving investment costs and possibly power losses.…”