| 摘要 |
A method for controlling connection of a transformer 7 of an electric vehicle, such as a train locomotive 1, to an alternating voltage supply carried by a trolley wire 2, the object being to reduce the transformer inrush current on connection of the transformer to the supply. The method comprises the steps of judiciously controlling movement of a pantograph 4 of the vehicle from its lowered position to a raised position so that as the pantograph approaches the trolley wire an arc bridges the air gap between them to consistently connect the electrical transformer of the vehicle to the trolley wire when the voltage present on the wire is at or near its peak. Furthermore, the vehicle's power system is controlled such that if the power supply to the trolley wire is lost while the pantograph is raised, the transformer is first isolated from the pantograph by a switch 6 and then after the power supply is restored, the pantograph is lowered, re-connected to the transformer by the switch 6 and re-raised to re-establish the connection with the trolley wire in the above judiciously controlled manner. |
