New Battery Monitoring Unit for HEV/EV Li-ion battery
作者单位：DENSO CORPORATION
会议名称：《2011中国汽车工程学会年会》
会议日期：2011年
关 键 词：EV and HEV systems Lithium ion battery Nickel metal hydride battery BMU Integrated Circuit
摘 要：Lithium-ion（Li-ion）batteries have higher energy content and power density than Nickel-metal hydride（NiMH）batteries,but require careful management for durability and *** NiMH batteries,which are controlled on a battery unit basis,each Li-ion cell generates a different ***,the complex controllers required to equalize individual cell voltages are large and *** have developed a fully functioning,low-cost,Li-ion battery monitoring unit（BMU） using an innovative new approach of embedding the cell-voltage equalizing and overcharge and overdischarge functions within an integrated circuit（IC）.This new unit also performs fault diagnosis and measures the battery’s internal resistance to monitor *** key innovations facilitated the implementation of the IC to create this compact,low-cost,Li-ion BMU:1) A proprietary cell-voltage balancing system to equalise the voltage of each individual cell of a Li-ion battery:This new cell-voltage balancing system eliminates much of the complex circuitry associated with conventional BMU *** voltage control methods use a microcomputer to measure the voltage of all the battery’s cells and discharges any above a target *** new approach replaces the analogue-to-digital converters（ADC） and microcomputer with a simple circuit that discharges any cells with a voltage greater than the average cell voltage across the battery,significantly reducing the size and cost of the BMU.2) A new overcharge/overdischarge detection method utilising unique algorithms and a single comparator circuit;This new approach combines both overcharge/overdischarge detection into a single comparator circuit embedded in the IC,eliminating the need for ADC and microprocessor.