A comparative study of battery balancing strategies for different battery operation processes

© 2016 IEEE. To reduce the effect of cell inconsistencies and improve battery pack capacity, battery balancing techniques are essentially required in battery management systems (BMSs). This paper presents a comparative study of four battery balancing strategies for different battery operation processes. These balancing strategies are developed from the state-of-the-art battery balancing circuits and algorithms reported in recent literature. The performance of balancing strategies is evaluated and compared by battery pack maximum available capacity, state of charge (SOC) variances at the end of charge (EOC) and end of discharge (EOD). The comparative result is helpful for BMSs developers to employ optimal balancing strategies in actual applications

Battery Pack Cells Mon itoring for Intelligent Charging

This dissertation intends to create a system capable of cell charging, cell balancing or both at the same time for batteries with multiple cells connected in series. It also tries to understand why there is only few literature connected with cell balancing and cell charging at the same time. For that purpose, this dissertation presents a review on the state of the art of many concepts related both to balancing and charging in order to pick the right methods and equipment to achieve the objectives of this work. This dissertation includes literature review on batteries, cell balancing methods and topologies, cell charging methods and a small review on state of charge estimation methods. Later on, this document studies and explains hardware and software requirements and choices in order to understand the final developed circuit. Lastly, development difficulties, results and conclusions are presented.Esta dissertação pretende criar um sistema capaz de carregar, balancear ou ambos em simultâneo num pack com diversas células ligadas em série. Tenta ainda perceber a razão de haver tão pouca bibliografia que junte em simultâneo carregamento e balanceamento de baterias. Para alcançar estes objetivos, esta dissertação conta com uma revisão do estado da arte de vários temas relacionados tanto com balanceamento como com carregamento de forma a perceber os métodos e equipamentos mais adequados para implementar. A dissertação inclui revisão bibliográfica em baterias, métodos de balanceamento e suas topologias, métodos de carregamento de baterias e ainda alguma revisão sobre métodos de estimação de estado de carga. Posteriormente, este documento estuda e explica os requisitos de software e hardware e as escolhas feitas para o desenvolvimento do circuito. Finalmente apresentam-se as dificuldades de desenvolvimento encontradas, os resultados e ainda algumas conclusões