New measuring method of contact loss of pantograph in AC electric railroads

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 low measurement accuracy and restricting conditions. 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, which uses a non-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