Conference Agenda

This paper addresses the challenge of ensuring electromagnetic compatibility between traction power supply systems and railway signaling systems by promptly identifying the causes of excessive interference in track circuits. Track circuits serve as the primary train position sensor in most existing railway signaling systems. Harmonics of the return traction current, flowing along the rails from the rolling stock to the traction substation, can distort the track circuit signal and, under certain conditions, lead to failures in train control systems. To maintain electromagnetic compatibility, new train types are tested before entering permanent operation to ensure their electromagnetic interference remains within acceptable limits. Additionally, during operation, the signal current parameters in the rails are periodically monitored. However, when excessive deviations from standard values are detected, identifying the root cause can be challenging due to the large number of influencing factors. Modeling the electromagnetic impact of traction currents on audio-frequency track circuits reduces the need for complex real-world measurements and, in some cases, can even replace them. This work aims to develop a computer model of the electromagnetic impact of traction currents on audio-frequency track circuits, facilitating the identification of possible causes of parameter deviations from standard values.

This article compares the susceptibility of GSM-R and FRMCS communication systems face to intentional jamming. GSM-R is the railway communication system currently used in Europe to ensure ground-to-train communications and signaling. FRMCS is the communication technology that should replace the GSM-R in the coming years to allow higher throughput.

Specific test benches have been set up to control quality indicators (BER or BLER) according to the power ratio between the communication signal and the jamming signal. The results are analyzed by considering the different configurations that the communicating solutions can take in terms of frequency band, modulation and redundancy.

Busbar plays a critical role in the power distribution network, enabling efficient current flow while minimizing parasitics, which can lead to critical voltage spikes during switching events. A careful design helps to significantly reduce stray inductance, that is particularly important in modern power converters using Silicon Carbide (SiC) semiconductors. These emerging new devices are faster, operate at higher switching frequencies, and are more sensitive to parasitic parameters, making the busbar’s low inductance essential for improving inverter performance and system reliability.

In this paper, the electrical characteristics of a busbar, including resistance (R), inductance (L) and capacitance (C), were computed using the Ansys Q3D simulator. The simulation, which employed a tetrahedral mesh for accurate modeling of current paths, calculated the inductance of the DC loop across a frequency range from DC to 1 GHz. The simulated loop inductance was approximately 30 nH. The software’s source and link features have allowed an accurate representation of the busbar’s electromagnetic performance, ensuring a precise calculation of the inductance values.

An experimental setup has been employed to validate the simulation results through a double pulse test, where one leg of the inverter has been subjected to switching events. Key parameters, such as DC-link voltage, collector-emitter voltage (VCE) of the IGBT, and collector current, have been measured. These measurements have allowed the calculation of the stray inductance of the busbar and comparison with the simulation results, ensuring the accuracy of the inductance calculations and assessing the busbar’s performance under real operating conditions.

The method for monitoring electromagnetic interference in the automation of urban rail transport (metro) was developed. It differs from existing methods by involving simultaneous measurements in the relay room at the relay ends of four track circuits as a train approaches the station. This approach makes it possible not only to detect electromagnetic interference in each track circuit but also to determine their parameters and predict faults in the traction equipment of electric trains. The results of experimental investigation are given.