Today, 60% of the European mainline railway network is electrified with 80% of total traffic. It will further increase driven by The Trans-European Transport Network (TEN-T) and sustainability initiatives. As electricity consumption by railway networks increases, quantification of rail transport’s actual energy consumption is essential. Currently, railways’ energy consumption is measured at the supply side, i.e., the grid, which includes the network’s losses. This measurement does not give actual energy consumption. The European Union demanded an on-board energy measurement system for railways from 2019 onward.

The existing energy measurement systems designed for transmission and distribution networks are not suitable for railway applications due to the harsh conditions. The voltage and current signals are highly distorted and need a more sophisticated measurement system. The energy measurement can be divided into current measurement, voltage measurement, and energy calculation. This thesis project is part of the ongoing research in the current measurement for the on-board energy measurement system focusing on the DC current measurement.

The primary objective is to measure the energy dissipated during braking of the train. Therefore, we need to measure the current flowing through the braking rheostat during the braking of the train. This current measurement is difficult due to the fast switching of high current (in order of 500 A-600 A) termed as chopped current.

VSL has developed a test setup to measure the chopped current flowing through the braking rheostat. The test setup is modified to eliminate distortions and achieve the project requirement of 600 A current measurement. Intermediate tests are performed during the modification to analyze the components’ performance. Finally, the modified setup is tested up to load current of 600 A, and uncertainty calculation performed on the measurement results.