Theoretical and Practical Study of the Effect of DC Grid Wire Temperature Variation on Transmission Losses

The ohmic resistance of DC lines causes losses during power transmission while variations in conductor temperature change the resistance accordingly. Typically, the resistances of specific wires mentioned in technical documentation correspond to some constant reference temperature which is usually 20°C. It was therefore decided to analyze the effect of the temperature of overhead catenary wires on the amount of transmission losses and total energy consumption in the case of trolleybus motion by means of simulations and calculations. In the practical part, an experimental study was performed to investigate how the voltage drop on DC lines increases due to temperature increase when an electricity consumer is operated at constant power.