Power Battery Active Equalization System Design And Implementation

With the rapid development of the world’s new energy vehicle industry,the battery system composition technology of new energy vehicles has also undergone tremendous innovations.From the initial lead-acid batteries to today’s lithium-ion batteries,the development of batteries has always been towards high energy density,The direction of high reliability.Battery pack life is one of the key issues.The biggest factor affecting the life of lithium-ion battery packs is the inconsistent characteristics between cells.Because of the short board effect,the greater the difference between the cells,the less the actual available capacity of the battery pack,and its actual life.It will be shortened,which greatly reduces the endurance of new energy vehicles,so it is necessary to balance the battery packs with a large dispersion of monomer characteristics.The traditional practical balance system generally relies on the passive energy consumption balance method for balance,and there is no balance.The efficiency can be said,and the equalization speed is slow,and the heat caused by energy consumption is also one of the unsafe factors.In order to solve the many shortcomings of the traditional balance management system,with the maturity of high-efficiency active balance technology and the emergence of new battery management system architecture,it is necessary to carry out research and implementation of related technologies.The first half of the text focuses on three aspects of research.First,the concept of wireless is introduced to the bus architecture of the lithium-ion battery management system,and the advantages of the wireless bus architecture of the battery management system are explained from various aspects,and the specific details are finally given.The wireless networking scheme has formulated the corresponding communication protocol;secondly,the balance part of the entire hierarchical battery management system is replaced with an active balance system from top to bottom,and the reason why the active balance has not been widely adopted in the past is introduced.A corresponding analysis is given for the reason.The upper-layer balance of the system adopts a soft-switching LLC resonant converter that is different from the previous hard-switching converters,which achieves a higher balance efficiency while simplifying the hardware structure,reducing failure rates and failures.The difficulty of troubleshooting.The single-cell balance in the bottom layer adopts the industry’s first active balance control IC.Its circuit structure is simple,the balance efficiency is high,and the final balance speed is significantly improved compared with the traditional method;finally a complete power battery layered balance strategy is formulated,First discussed the two key factors of equilibrium criterion and equilibrium timing,and finally formulated a reasonable equilibrium strategy after comprehensive consideration.Finally,the physical object and code logic of the produced equalization system are introduced,mainly including the circuit schematic diagram and PCBA design of the single board of the LLC inter-group equalization converter,the intra-group equalization converter,and the inter-group equalization converter digital controller,and the system is introduced.The execution logic of each part of the key code finally tested each part of the system and the overall working performance.The overall test result met the expected design index,and the introduction and verification of the cutting-edge technology of the lithium-ion battery balance management system was completed.