31. Multi-segment pantograph head with high compliance to contact wire fluctuation

Giving the cross-section of a pantograph head a curved surface is an effective measure to reduce aerodynamic noise. This type of conventional pantograph head however needs to be fitted with a flexible contact strip support in order to follow to the unevenness of the contact wire (the whole contact strip moves vertically against the cross-section of the pantograph head). In doing so in this type of pantograph head, the vertical movement of the contact strip makes the lift force susceptible to change, which can at high speeds induce unwanted vibration in the pantograph head.

For solving this problem a multi-segment pantograph head was proposed. In order to guarantee both low noise and lift force stability, the shape of the pantograph head cross-section was made to be curved, and to be used only in one travel direction. In addition, the pantograph head itself was divided into segments, so that each segment of the pantograph head was capable of vertical movement whilst maintaining the same cross-section shape, in order to follow to the contact wire. In order to keep the weight of each moving part as low as possible, a carbon composite contact strip was adapted to the multi-segment pantograph head and a prototype was built (Fig. 1) and compared to a conventional type pantograph head with flexible contact strip support for current collection performance (Fig. 2). Compared to the conventional pantograph head, the compliance performance of the multi-segment pantograph head to contact wire unevenness corresponding to the frequency band of dropper intervals at a running speed of 300-400 km/h was ten times higher (Fig. 3). In addition, it was confirmed that the contact loss ratio was reduced by about 50% at a running speed of 300km/h with a current of 400A (Fig. 4).

This prototype will contribute to further improving pantograph design.