Our contribution

Enotrac carried out a comprehensive traction power supply modelling study for the Melbourne Metro Tunnel using its software tool Fabel. Simulations included load calculations, energy studies and harmonic analyses, each considering outage scenarios (N-1), as well as emergency situation recovery scenarios.

The study was carried out in two stages. First, Enotrac completed network calculations for dimensioning the energy supply. Calculations with FABEL indicated very high demands were made on the availability of the system. The system includes inverters at 3 tunnel rectifier substations, the benefits of which were demonstrated by means of simulations. Both the 1500 V DC traction current network and the 22 kV / 50 Hz feeding network were modelled.

In the second stage of the study, network and magnetic field calculations were carried out to verify electromagnetic compatibility (EMC) with the surrounding systems, as the tunnel runs close to a hospital and university with equipment sensitive to magnetic radiation (such as MRI machines). The EMFCalc3D module integrated in Fabel was used to determine and evaluate the magnetic interference at the locations with sensitive equipment.

The overall system was optimised in terms of reducing the electromagnetic interference and complying with the limit values of the sensitive equipment for proof of electromagnetic compatibility. Independently carried out measurements showed excellent agreement between measurements and calculations.

Enotrac contributed significantly to the success of the project, because without the plausible proof of electromagnetic compatibility, the project could have been blocked by third parties, in this case stakeholders at the neighbouring hospital and university. Cooperation with the engineering firm PowerEarth was also very positive.