Design and Implementation of a Battery Equalisation System for Electric Vehicles

The Design and Implementation of a Battery Equalisation System for Electric Vehicles addresses the critical need for effective battery management in electric vehicles (EVs). The introduction outlines the motivation behind the project, which stems from the increasing reliance on electric vehicles as a sustainable alternative to combustion engines. The battery equalisation system aims to enhance the performance and longevity of batteries by ensuring that all cells within a battery pack maintain optimal charge levels. This section emphasizes the importance of battery health in achieving greater vehicle efficiency and range. The project overview provides insights into the specific goals of the research, including the development of a prototype that can be integrated into existing EV systems. The introduction sets the stage for the detailed exploration of battery technologies and equalisation methods that follow.

This section delves into various battery monitoring techniques and equaliser topologies essential for maintaining battery health. It discusses the significance of monitoring battery voltage, temperature, and state of charge to prevent damage and ensure optimal performance. The section categorizes different topologies, including common bus, common core, and ring topologies, each with its advantages and limitations. The selection of an appropriate topology is crucial for the effective implementation of the battery equalisation system. The analysis highlights how these topologies can be adapted to meet the specific requirements of the EV3 project. The section concludes with a discussion on the selection criteria for the voltage equaliser configuration, emphasizing the need for a balance between efficiency, cost, and performance.

The converter design section focuses on the development of three types of converters: the 24W buck-boost converter, the 192W buck-boost converter, and the 192W flyback converter. Each converter is designed to operate under current mode control, ensuring stable performance during battery equalisation. The section provides a detailed analysis of the design considerations for each converter, including the selection of components such as MOSFETs and inductors. The design process emphasizes the importance of achieving high efficiency, with experimental results indicating efficiencies between 90% and 92%. The converters are engineered to be compact and lightweight, facilitating easy integration into the EV framework. This section underscores the practical implications of the converter designs in enhancing the overall performance of the battery equalisation system.

In the performance records section, the effectiveness of the battery equalisation system is evaluated through experimental setups. The results demonstrate successful equalisation between both non-isolated and isolated battery banks. The section details the methodologies used to assess performance, including voltage measurements and efficiency calculations. The findings reveal that the designed equaliser can effectively balance the charge levels across multiple battery cells, thereby extending battery life and improving vehicle range. The significance of these results lies in their potential to inform future developments in battery management systems for electric vehicles. The section concludes with recommendations for further research and improvements based on observed performance metrics.

The conclusion synthesizes the key findings of the thesis, reiterating the importance of a robust battery equalisation system in the context of electric vehicles. It reflects on the successful design and implementation of the converters, highlighting their efficiency and adaptability. The conclusion also addresses the broader implications of this research for the future of electric vehicle technology, emphasizing the need for continued innovation in battery management solutions. The potential for real-world applications is significant, as improved battery performance can lead to enhanced vehicle efficiency and sustainability. The thesis ultimately contributes valuable insights to the field of electrical engineering and the ongoing development of electric vehicles.