Interference between electric traction supply network and distribution power network - resonance phenomenon

Electric traction is one of the biggest appliances in power network and can have a significant influences on supply network. These influences include non-harmonic currents and voltages, unsymmetric loading of the three phase system or rapid fluctuation in power consumption. Traction network, feeding network, traction transformer and, in some cases, filtration-compensation unit, altogether form a system of inductivities, capacities and resistances. That is why resonances can occur in this system. This paper investigates these resonance phenomena in a traction transformer substation that feeds alternate electric traction. The paper includes a theoretical analysis of the problem, computer simulation, and results of measurements in the transformer substation where resonances were recorded.