About the project

BVB operates an urban transport network with nine tram lines and more than 90 tram compositions serving Basel’s city centre and the surrounding area. The closely meshed route network in Basel and the high frequency on the individual lines place high demands on the performance and reliability of the energy supply, which is guaranteed by Industrielle Werke Basel (IWB).

They supply the traction current network with 600 V direct current via 25 substations, which are fed from the local network. The BVB catenary network is also connected at three locations to the network of the transport operator Baselland Transport (BLT) from the neighbouring half-canton of Basel-Land. BLT also operates four lines on the BVB infrastructure.

The study provided a basis on which BVB could conduct discussions on emissions reduction, marketing and compliance with the mission statement. The aim of the study was to show for the first time the extent of the possible benefits as well as the profitability of possible measures.

Graphic representation of the proportion of unused braking energy along the route, determined from the simulation and shown on the map

Driving profile from the simulation for a tram route with different network conditions

Our contribution

Enotrac has examined the benefits and profitability of different measures to reduce the existing level of rheostatic braking energy (rheostat = a variable resistor which is used to control current) dissipated in the network.

Enotrac carried out a system / network study, employing network calculations with Fabel to examine the benefits of each measure in detail. The measures examined included:

  • Increasing the recuperation voltage on the vehicles
  • Optimisation of the network circuit
  • Increasing the system voltage from 600 V to 750 V
  • Increasing the cross-section of the overhead contact line
  • Vehicle-based and wayside energy storage and inverter systems at suitable locations in the network.

To evaluate the benefits of each measure, simulations were used to determine the respective energy consumption in the entire tram network. These simulations were then compared with a baseline simulation. The difference between the total energy consumption simulated showed the amount of energy saved with each of the potential measures, i.e. the technical benefit. As a general rule. all simulations in the investigation were based on medium loads in order to be as close as possible to average annual energy consumption values.

Enotrac conducted an economic appraisal to determine the profitability of each measure based on their simulated technical benefits. From the results, Enotrac summarised a package of measures, which was presented to BVB for implementation.

The results of the study were presented at the International Conference for DC Railway Energy Supply Systems DCRPS in Leipzig in January 2020.

  • Customer

    BVB – Basler Verkehrs-Betriebe

  • Period


  • Location

    Basel, Switzerland

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