Traction assembly including a locomotive and a tender and associated method

A traction assembly comprising a dual-current locomotive, the dual-current locomotive comprising:

• a single-phase pantograph configured to collect a single-phase current from an overhead wire and a direct current pantograph configured to collect a direct current from the overhead wire;
• a roof line to which the single-phase pantograph and the direct current pantograph are electrically connected;
• a single-phase switch electrically connected between the roof line and a single-phase power supply circuit of at least one traction motor of the dual-current locomotive;
• a direct-current-phase switch electrically connected between the roof line and a direct-current power supply circuit of the at least one traction motor of the dual-current locomotive;
• a sensing circuit adapted to detect instantaneous properties of a voltage on the roof line, and a control system adapted to command, as a function of the instantaneous properties of the voltage on the roof line detected by the sensing circuit, an open or closed state of the single-phase switch and an open or closed state of the direct-current switch,
• wherein said traction assembly further comprises a tender mechanically coupled to the dual-current locomotive, the tender carrying an energy storage configured to deliver a current for supplying the at least one traction motors of the dual-current locomotive, the energy storage having a first terminal and a second terminal, and
• wherein the tender is electrically connected to the dual-current locomotive in such a way that the first terminal is directly electrically connected to the roof line of the dual-current locomotive by a high-voltage cable and the second terminal is connected to a point on the dual-current locomotive which is set to a reference potential, so that when the energy storage is activated, a tender voltage is applied from the first terminal of the energy storage to the roof line, and, based on the sensing circuit detecting the tender voltage on the roof line, the control system commands the open or closed states of the single-phase switch and the direct-current switch to power the single-phase power supply circuit or the direct current power supply circuit with a tender power delivered by the energy storage of the tender.