鋰離子電芯電壓量測電路之研究

Study of Lithium Ion Cell Voltage Measuring Circuits

鋰離子單電芯電壓的精確量測是鋰離子電池組電池管理系統所必備的重要功能，本研究探討多個合適的鋰離子單電芯電壓量測電路，如分壓電阻量測電路、差動放大器量測電路、類比多工器加差動放大器量測電路、光繼電器加差動放大器量測電路、光繼電器量測電路、多工器加光繼電器量測電路，深入研究各個電壓量測電路之優缺點，並自行開發出一個植基於DMOS 元件的鋰離子單電芯電壓量測電路，本文除了對本電路做仔細的描述，並以一實做的電路應用於一組8 個單電芯串聯的電池組上進行充放電時各單電芯電壓的量測，量測的結果顯示本電壓量測具有高精確度與可靠度。

The accurate measurement of cell voltages in a lithium ion batterymodule in series is an important function required by a battery managementsystem. This paper investigates some of the suitable cell voltage measurementcircuits: voltage divider circuit, differential amplifier voltagemeasuring circuit, differential amplifier/ analog multiplexer voltage measuringcircuit, photo coupler voltage measuring circuit, and photo coupler/analog multiplexer voltage measuring circuit, for lithium ion batterymodules. Rigorous evaluations of the selected voltage measuring circuitsare presented in the paper. To improve the shortcomings of the existingvoltage measuring circuits, a new voltage measuring circuit based onDMOS component is designed in this paper. Detailed investigation of thenewly developed DOMS based voltage measuring circuit is also presentedin the paper. Experimental results show good accuracy and reliability ofthe DOMS based voltage measuring circuit.