Voltage Divider Design for DC Traction in Tramway Networks

This paper presents the study and development of a high-performance voltage transducer for the accurate monitoring and control of traction voltage in tramway systems. The proposed transducer offers a more effective alternative to the Hall-effect sensors currently adopted, which suffer from some drawbacks such as limited frequency bandwidth and unsuitability for outdoor applications. The research activity is carried out in different steps. Initially, the typical characteristics of the voltage signals to be monitored, such as amplitude dynamics and spectral content, are analyzed. Attention is then focused on the environmental conditions in which the monitoring voltage transducer must operate. These preliminary analyses allowed for the definition of the key design constraints for the sensor under study. The article describes the implementation of the voltage transducer, with particular focus on the transducer typology, components selection, and insulation techniques, tailored to the identified design constraints. Preliminary results from laboratory experimental tests are presented and discussed, demonstrating the voltage transducer's high performance, with amplitude linearity within tens of ppm from 50 V to 1 kV and a frequency response error lower than 0.15% up to 2 kHz.