具主從架構之電池管理系統開發

Development of a BMS with Master-Slave Topology

鋰離子電池具有高能量與功率密度，近代的電動車為提升性能因此主要採用鋰離子電池，但鋰離子電池需要先進的電池管理系統對任一電芯進行保護、平衡與殘電量估測等管理，若無任何電池管理或不適當的電池管理，鋰離子電池容易產生致命性的損壞，電池管理系統對電動車的重要性可見一斑。本文開發一套多模組串聯的鋰鐵磷電池管理系統，此電池管理系統由模組電池管理系統 （slave） 與主管理板 （master） 的主從拓樸 （topology） 所組成，模組電池管理系統管理48 V 電池模組之16 顆鋰鐵磷電芯，主管理板則與各模組電池板進行資料與命令的雙向通訊，執行電池系統的管理任務。本研究所開發出之電池管理系統可以準確的量測電池參數，並根據預設值對電池進行過充或過放保護，也藉由主動平衡技術對串聯電池芯進行容量平衡補救，三階段的殘電量估測法則提供可靠的電池容量資訊，車載資料擷取卡則提供研究人員即時且長期的電池運轉資料，對電池與管理系統的長期性能評估助益很大。

Lithium batteries, which are high in energy and power densities, areadopted by modern electrical vehicles (EV) to improve driving performance.However, lithium batteries require advanced battery managementsystems (BMS) to prevent going cells out of electrochemical limits; balancethe state of charges among cells in series; and estimate battery state ofthe charge. Fatal accidents could happen to lithium batteries without appropriateBMS. BMS is instrumental for lithium battery systems.This article presents the development of an advanced BMS for multipleLithium iron phosphate (LFP) battery modules connected in series.The configuration of multiple battery modules connected in series is commonly present in EVs. The current BMS is based on a master andslave topology design. Each 48 V battery module with 16 cells connectedin series is managed by a module BMS, which serves as the slave, and amain control board, which is the master, coordinates two way communicationbetween master and slaves and execute battery management actions.The developed BMS was shown to measure battery parameters accurately;protect cells from overcharging and over discharging according topreset limits; conduct innovative active cell balance to compensate cellcapacity inconsistencies; and predict a reliable battery state of charge witha devised two-stage method. A vehicle information system with vehicledata acquisition function was designed in the current work. This vehicleinformation system, providing both real-time presentation and post analysisfunctions, facilitated long term performance evaluation of the developedBMS in the current study.