Davood Younesian - Railway Engineering Department Iran University of Sci & Tech Tehran ۱۶۸۴۶-۱۳۱۱۴, Iran
Ali Asadi Lari - Railway Engineering Department Iran University of Sci & Tech Tehran ۱۶۸۴۶-۱۳۱۱۴, Iran
Jaleh Hosseinzadh - Railway Engineering Department Iran University of Sci & Tech Tehran ۱۶۸۴۶-۱۳۱۱۴, Iran

For an electrical railway overhead wire system there aretwo main factors which crucially affect the quality ofcurrent collection. One is the spatial stiffness variation of the overhead wire along each span and the other is the flexural wave motion in the wire. Variation of thestiffness in overhead system induces a parametricallyexcited type vibration in the pantograph system. Vibration control of the pantograph system due toperiodicity of the catenary stiffness is discussed in thispaper. Two approaches i.e. Zigler-Nichols PIDcontroller as well as the optimal control theory areutilized and their performances are investigated. Acomprehensive parametric study is carried out to figure out how different parameters such as the train speed,type of controller and controller gains may affect thevibration level. It is found that the designed LQRcontroller works more efficiently with more reasonablelevels of actuating forces.

parametrically excitation, nonlinear vibration, LQR controller, pantograph, overhead wiresystem, Mathieu equation