燃料電池電動腳踏車與代步車之系統整合與控制

Abstract

本論文進行燃料電池電動腳踏車與電動代步車之系統整合與控制，以質子交換膜燃料電池搭配二次電池，作為電動車的電力源，並發展串並聯電力管理策略，運用在不同的電動車上進行比較。研究主要分為三個部分來執行：燃料電池的控制、電力管理系統的設計、以及電動車的整合與比較。 本論文採用兩組燃料電池系統。第一組燃料電池用於電動腳踏車，其輸入為氧氣與氫氣，輸出為燃料電池的電流，我們稱之為MISO燃料電池；沿用實驗室之前發展的強韌控制器設計方法，我們可以控制氫氣比例閥及空氣幫浦，有效地減少氫氣消耗與提昇系統性能，並達到穩定輸出電流的目標。第二組燃料電池用於電動代步車上，我們稱之為SISO燃料電池，其輸入為氫氣，輸出為燃料電池的電壓，我們可以控制電磁閥來調節氫氣的輸入量，以達到減少氫氣的消耗之目標。 其次，我們發展電力管理系統。我們以MISO燃料電池搭配兩組磷酸鋰鐵電池，發展串聯式混合電力鏈，並依據其動態特性制定適合的電力管理策略：以一個電池組提供電力給後端電動馬達，另一個電池組作為備用電源；當第一個電池組的殘電量降至一個定值時，切斷其供電迴路並控制燃料電池進行定電流充電，並且啟動另一個電池組進行供電，以維持電力的持續供應。另外，我們以SISO燃料電池搭配一組磷酸鋰鐵電池，規劃並聯式混合電力鏈：在低負載時由燃料電池對後端馬達供電；在高負載時則由二次電池輔助燃料電池同時對後端馬達供電。 最後，我們將上述MISO及以SISO燃料電池分別與電動腳踏車及代步車進行系統整合，以提供電動車穩定且持續的電力來源，並以實驗結果討論其系統效率，及不同電力管理策略的優缺點。

This thesis focuses on the control and integration of fuel-cell powered light electric vehicles. The study was carried out in three steps: fuel-cell control, power management, and system integration. In this thesis, we used two proton exchange membrane fuel-cell (PEMFC) to the proposed electric vehicles. The first one was called the MISO FC because it has two inputs of hydrogen and air and one output of cell-current. Therefore, we applied multivariable robust control to the proportional valve and air pump to reduce hydrogen consumption while providing steady current for charging the secondary battery sets. The second fuel-cell was called the SISO FC because it has an input of hydrogen flow rate and an output of cell-voltage. Therefore, we can control the solenoid valve to regulate the hydrogen flow rate and reduce hydrogen consumption. Second, we developed power management for the electric vehicles. We applied the MISO FC to the electric bicycles and designed a serial power-train, which consisted of the PEMFC and two 23.1V 6.9Ah LiFePO4 battery sets. The bike motors were directly powered by the battery set to avoid damaging the PEMFC due to rapidly varying loads. And the battery sets were charged in turn by the PEMFC when their capacities droped to a certain level. For comparison, we applied the SISO FC to the electric mobility scooter, and developed a parallel power-train that consisted of the PEMFC and one 23.1V 6.9Ah LiFePO4 battery set. The scooter motor was directly powered by the PEMFC at low loading mode, while the battery provided auxiliary power at the high loading mode. Lastly, we integrated the two PEMFC with the proposed electric vehicles, and verified the system performance by experiments. Based on the results, the proposed PEMFC powered electric bicycles and mobility scooter are deemed effective.