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Journals

2006 Journal of the Chinese Institute of Engineers

Time and Frequency Domain Identification and Analysis of a Permanent Magnet Synchronous Servo Motor

 

Jui-Jung Liu, Ya-Wei Lee, Fu-Cheng Wang, Ramesh Uppala and Ping-Hei Chen

 

 

Abstract
This study employed the approach of non-linear autoregressive moving average model with exogenous inputs (NARMAX) to analyze the dynamics of a Permanent Magnet Synchronous Motor (PMSM). The non-linearity in PMSM including cogging force, reluctance force and force ripple is difficult to estimate. By using the NARMAX approach, thrust-speed relationship and thrust-position relationship could be analyzed by identifying both time and frequency domain models of the system. The frequency domain analysis is studied by mapping the discrete-time NARMAX models into generalized frequency response functions (GFRFs) to reveal the non-linear coupling between the various input spectral components and the energy transfer mechanisms in the system. From the results, the interpretation of the higher-order GFRFs has been comprehensively studied and non-linear effects have been related to the physical models of the systems.
Conference

2006 Proceedings of the 45th IEEE Conference on Decision and Control

The Performance Improvements of Train Suspension Systems with Inerters

 

Fu-Cheng Wang, Chung-Huang Yu, Mong-Lon Chang and Mowson Hsu

 

 

Abstract
This paper investigates the performance benefits of train suspension systems employing a new mechanical network element, called Inerter. Combined with traditional passive suspension elements - dampers and springs, Inerter is shown to be capable of improving the performance, in terms of the passenger comfort, system dynamics and stability (safety), of the train suspension systems. Furthermore, a motor-driven platform is constructed to test the properties of suspension struts with inerters.

2006 Proceedings of the Fourth International Conference on Fuel Cell Science, Engineering and Technology

Proton Exchange Membrane Fuel Cell System Identification and Control: Part II: H-infinity based Robust Control

 

Fu-Cheng Wang, Yee-Pien Yang, Hsin-Ping Chang, Ying-Wei Ma, Chih-Wei Huang, and Biing-Jyh Weng

 

 

Abstract
This paper applies robust control strategies to a PEM fuel-cell system. In Part I of this work [17], a PEM fuel cell was described as a two-input-two-output system with the inputs of hydrogen and air flow rates, and the outputs of cell voltage and current. From the responses, system identification techniques were adopted to model the system transfer function matrix. Then adaptive control methods were applied to control the system with encouraging results. In this paper, the H-infinity robust control strategy is proposed due to the highly nonlinear and time-varying characteristics of the system. From the results, it is illustrated to be an efficient control method for the fuel cell systems.

2006 Proceedings of the Fourth International Conference on Fuel Cell Science, Engineering and Technology

Proton Exchange Membrane Fuel Cell System Identification and Control: Part I: System Dynamics, Modeling and Identification

 

Yee-Pien Yang, Fu-Cheng Wang, Hsin-Ping Chang, Ying-Wei Ma, Chih-Wei Huang and Biing-Jyh Weng

 

 

Abstract
This paper consists of two parts to address a systematic method of system identification and control of a proton exchange membrane (PEM) fuel cell. This fuel cell is used for communication devices of small power, involving complex electrochemical reactions of nonlinear and time-varying dynamic properties. From a system point of view, the dynamic model of PEM fuel cell is reduced to a configuration of two inputs, hydrogen and air flow rates, and two outputs, cell voltage and current. The corresponding transfer functions describe linearized subsystem dynamics with finite orders and time-varying parameters, which are expressed as discrete-time auto-regression moving-average with auxiliary input models for system identification by the recursive least square algorithm. In experiments, a pseudo random binary sequence of hydrogen or air flow rate is fed to a single fuel cell device to excite its dynamics. By measuring the corresponding output signals, each subsystem transfer function of reduced order is identified, while the unmodeled, higher-order dynamics and disturbances are described by the auxiliary input term. This provides a basis of adaptive control strategy to improve the fuel cell performance in terms of efficiency, transient and steady state specifications. Simulation shows the adaptive controller is robust to the variation of fuel cell system dynamics.