Charging substation with balancing converter for AC 15 kV 50 Hz put into operation

 

A charging substation with balancing converter was put into operation for the first time at Alstom’s plant in Salzgitter
and tested together with a BEMU.

Rail Power Systems GmbH (RPS) and F&S PROZESSAUTOMATION GmbH (F&S) have completed the jointly developed compact charging substation for a charging voltage of AC 15 kV 50 Hz [1]. The charging substation was transferred from Dohna near Dresden to Alstom’s plant in Salzgitter by road and set up ready for operation there within four days in mid February 2023.

Commissioning was performed in two phases. First the charging substation was tested in non-load mode and the functions and protective settings checked. In the second phase, Alstom supplied the Coradia Continental 1440 402 traction unit, a vehicle from the pre-series of BEMU for the Verkehrsverbund Mittelsachsen (VMS). They are intended to be used on the Leipzig – Chemnitz line in future. The vehicles have been upgraded for a changing voltage of AC 15 kV 50 Hz in addition to the otherwise customary contact line voltage of AC 15 kV 16,7 Hz.

Alstom engineers from Salzgitter, Charleroi (BE) and Tarbes (FR), who are responsible for the vehicle, provided support for the tests. The software in the drive control unit has been adapted for 50 Hz operation. The measurements were supervised scientifically by the Chair of Electric Railways at the Technical University of Dresden.

On-road transport of the charging substation to Salzgitter.

Charging substation (left) and test train at Alstom’s plant in Salzgitter.

The tests applied to the interplay of the balancing converter with the other components of the charging substation, their interaction with the vehicle in different operating modes, the behaviour with regard to the supply network with and without a vehicle and their balancing function and network-supporting effect. The vehicle was initially operated within a power range of up to 150 kVA. The tests verified that it is possible to supply the vehicles with AC 15 kV 50 Hz without problems and without loading the three-phase network with asymmetries or high harmonics. Furthermore, vehicle-specific tests were conducted. Powers of up to 1.2 MVA are planned in a second test series.

The tests are a prerequisite for the transfer of the charging substation to the station Annaberg-Buchholz Süd [2]. The preparations for the setup of a charging station have been more or less completed there. The charging substation is to be tested in actual operating conditions and made available to other vehicle manufacturers here. DB Energie GmbH, DB Regionetz Infrastruktur GmbH Erzgebirgsbahn and Smart Rail Connectivity Campus (SRCC) took part in the development project in addition to the companies already mentioned.

Publications

[1] Lindenmüller, L.; Müller, M.; Northe, J.; Röhlig, S.: Concept for 50 Hz charging stations for battery electric multiple units with balancing converter. In: Elektrische Bahnen 119 (2021), issue 3, pp. 90–99.

[2] Cooperation project for ETA changing station AC 15 kV 50 Hz. In: Elektrische Bahnen 120 (2022),issue 9, pp. 366–367.