Topology, Analysis, and Modulation Strategy of a Fully Controlled Modular Reconfigurable DC Battery Pack With Interconnected Output Ports for Electric Vehicles

Abstract

Modular battery-integrated converters or so-called dynamically reconfigurable battery packs are expanding into emerging applications. Although they offer many degrees of freedom (DoF), the state of the art focuses on single-output systems and neglects the potential of such systems to generate multiple outputs with minimum added components. This paper investigates the feasibility of a multiport system for various independent loads. The proposed techniques can achieve higher functionality and reduce power conversion stages. Interleaved ports with shared modules can also increase modules’ utilization, avoid redundant power electronics, and reach a better cost-weight trade-off. However, using conventional modulation techniques in particular phase-shifted carrier modulation can be challenging with shared modules among multiple ports, and different control objectives can adversely impact the overall performance. Therefore, this paper analyzes the inherent dynamics of modular batteries and proposes a strategy to decouple the control of multiple ports to simplify power electronics’ complexity and size while improving performance. In addition to the distinct advantages of modular reconfigurable batteries, the proposed concept would not require additional active switches, can operate with a wide range of output voltages, can reduce the size of the filters and transformers, and is extendable to larger setups. Simulation and experiments verify the developed concept.