A method to continuously measure irregularities in trolley wires with sufficient accuracy is already in existence. However, determining the necessity for overhead contact line repair under static measurement conditions also depends on overhead contact line structure, pantograph conditions and running speed. A technique was therefore proposed to quantitatively evaluate and diagnose the erection accuracy considering the dynamic characteristics by estimating variations in contact forces during pantograph running, based on the results of trolley wire irregularity measurement.

      To consider the influence of wave motion through the trolley wire, the contact force of the pantograph and the vibration of trolley wire were determined using the simulation technique of overhead contact line/pantograph motion. It was verified that the simulation values corresponded closely to the vehicle running test results (Fig.1). Using this method enables quantitative estimation of locations where the trolley wire is excessively lifted or distorted, or where the pantograph loses contact with the trolley wire (Fig.2). This contributes towards faster service, identification of repair locations and numbers, and improvements in the efficiency of trolley wire maintenance.

Fig.1 Accuracy of the dynamic characteristics evaluation (trolley wire vibration when pantograph passes)


Fig.2 Example of the dynamic characteristics evaluation of trolley wire facilities (Shinkansen running with two pantographs)