燃料電池單電池電壓量測系統設計與實現

Design and Implementation of A Single Cell Voltage Measurement System on A Fuel Cell Stack

燃料電池堆運轉時，對每一片單片電池之即時電壓的監控，才能夠掌握每一片單電池的狀態與性能，單片電池電壓的量測也能提供燃料電池老化程度的判斷依據，惟燃料電池通常由約10 到100 片單電池串聯而成，要能即時且同步的量到每片單電池的電壓，並不是一件容易的工作。本研究開發燃料電池單電壓量測系統以即時量測、顯示、儲存燃料電池的單片電壓，當燃料電池單電壓顯示異常 （單一片電壓波動幅度大或電壓過低） 時，可讓操作人員即時採取保護的措施，以免損壞整個電池堆或降低電池的性能。本文提出植基於微控制器及差動放大器電路之燃料電池單電壓量測系統方法，並將燃料電池單電池電壓量測系統以1 個微控制器，對應至12 片電池電壓方式模組化，並配合燃料電池量測上之限制，發展特殊的燃料電池多點單片電壓採集量測探頭裝置及固定方式，包括探頭、整合型端子台以及模組化排線等，最後本文章會呈現長期運轉測試結果。

Monitoring the voltages of every single cell of a fuel cell stack allowsfull control of the conditions and performance of each cell while the stackis in operation. Measuring the voltages of every single cells provides areliable means to spot the deteriorating of a fuel stack. Howevery, a fuelstack usually is composed of 10 to 100 single cells connected in series.It’s not an easy task to simultaneously measure every single cell in realtime. This study developed a single cell voltage measurement system tomonitor every single cell voltage of a fuel cell stack in real time. Armedwith this single cell voltage system, fuel cell stack operators can takeprecautionary measures when any single cell voltage becomes too low orabnormally unstable. Catastrophic failure of the whole fuel cell stack cantherefore be avoided with this single cell voltage monitoring system. Amicro controller based single fuel cell measurement circuit mainly con sisting of difference amplifiers was designed and assembled in the currentstudy. In consideration of scalability and flexibility, a modular approachwas adopted in this study with one module measuring the voltages of 12single cells. An innovative probe design was also realized in the currentstudy to overcome the difficulty of sticking voltage probes on flat fuel cellsurfaces. The current single fuel cell voltage measurement system wastested on a 2.5 kW rating fuel cell stack with 36 single cells. The testresults are presented in this article in detail.