New Detection Method for Contact Loss of Pantograph

It has become very important to correctly grasp the contact loss between contact wire and pantograph, evaluate the current collection performance and diagnose the overhead contact line equipment of electric railroads. Although some methods have already been developed to measure contact loss, they are not practical because of the restriction, on measurement accuracy, by noise. We devised a new method to measure contact loss from feeble current changes produced between a pantograph and the ground at the moment of contact loss. The new method uses a no-current collection pantograph of inspection car used for Shinkansen AC electric railroads. In the examination by an inspection car installed with the measuring equipment, we confirmed that it was possible to obtain good response to contact loss.