強韌PID控制器於質子交換膜燃料電池系統之設計及安裝

Design and Implementation of Robust PID Controllers for a Proton Exchange Membrane Fuel Cell System

柯致雋(Chih-Chun Ko)

指導教授 ： 王富正

國立臺灣大學/工學院/機械工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.01165

摘要

本論文將強韌PID控制應用於一個質子交換膜燃料電池系統。吾人首先利用系統識別，找出燃料電池系統的數學模型；然後設計強韌控制器，調節空氣與氫氣的流量，以達到穩定輸出電壓、減少氫氣消耗與能量消耗的目標；最後則將設計的強韌控制器與周邊元件控制整合於單晶片，達到系統微化的目標。
燃料電池將化學能轉換為電能，內部包含複雜的電化學反應，是一個非線性時變系統。吾人從系統的觀點來看，將其視為一個雙輸入雙輸出系統，其輸入為空氣與氫氣的流量，輸出為燃料電池的電壓與電流；若是接續負載為固定，則可進一步將其簡化為雙輸入單輸出系統。本文以系統識別方法，在各操作點將質子交換膜燃料電池視為雙輸入單輸出之線性系統，而將非模型化之動態視為系統不確定性與外部干擾，並利用強韌控制來達到穩定系統與增進效能之目標。因為一般電器產品都需要穩定的電壓源，所以強韌控制器的設計目標是穩定輸出電壓、減少氫氣的浪費、與得到較好的燃料電池輸出效率。另外，針對業界廣為使用的PID控制器，本文結合強韌控制理論與PID控制的特性，設計強韌PID控制器，以低階的控制器達到預期的控制目標。最後將所設計的強韌PID控制器安裝於單晶片上，實現系統微化的目標。實驗結果顯示，強韌PID控制確實可以增進燃料電池系統穩定性能。

關鍵字

質子交換膜燃料電池 ； 系統識別 ； 強韌PID控制 ； 強韌控制 ； 氫氣使用效率 ； 功能效率

並列摘要

This thesis proposes the design and implementation of robust PID controllers for a proton exchange membrane fuel cell (PEMFC) system. First, we model the PEMFC as a multivariable plant by identification techniques. Second, we apply multivariable robust control strategies to stabilize the output voltage, and to improve system performance and efficiencies. Finally, the designed robust PID controllers are implemented on a microcontroller for system miniaturization.
PEMFC systems are nonlinear and time-varying. However, from the system point of view, the dynamics of PEMFC can be represented as a two-input-two-output system, that has inputs of air flow rate and hydrogen flow rate, and outputs of stack voltage and current. By fixing the output resistance, the system can be further reduced to a two-input-single-output system. Because most electrical equipment requires steady voltage supply, we aim to maintain steady output voltage for the PEMFC system.
We first identify the models of the PEMFC system at different operating points, and regard the un-modeled dynamics as system uncertainties. Since robust control is well known for its ability to cope with system uncertainties and disturbances, we then design a standard robust controller to improve stability and performance of the PEMFC system. However, the standard robust controller might be too complex for implementation, because the order of the controller is determined by the orders of the plant and weighting functions. On the other hand, PID control has been widely applicable to industrials because of its simple structure, but it lacks stability analysis for systems with uncertainties. Therefore, combining the merits of robust control and PID control, we design robust PID controllers for the PEMFC system. The designed controllers are then implemented on Simulink to experimentally verify the system performance. Lastly, the robust controllers are implemented on a microcontroller unit for system miniaturization. From the results, the proposed robust PID controllers are shown to be effective.

並列關鍵字

Proton Exchange Membrane Fuel Cell (PEMFC) ； System identification ； Robust PID ； Robust control ； Hydrogen efficiency ； Power efficiency

參考文獻

[34] 周銘城，質子交換膜燃料電池控制及整合，國立台灣大學機械工程研究所碩士論文，2009。

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