Methodology of selecting compensating devices in the ac traction power supply system

The paper considers a traction power supply system with a voltage of 27,5 kV AC. In the MATLAB-Simulink software environment, a calculation model has been developed that takes into account the parameters of the external power supply system, the train schedule and the current consumption of the electric traction load in the inter-substation zone. It is shown that when choosing the power of the compensating device according to the average value of the reactive power consumed by one train, its passage through the inter-substation zone with direct current causes the same average power losses in the wires of the catenary as in the absence of a compensating device. An increase in the number of trains simultaneously located in the inter-substation zone with the same power of the compensating device entails a decrease in power losses in the wires of the catenary relative to a similar situation without a compensating device, however, the reactive power is only partially compensated. In the calculations of compensating devices, it is proposed to take into account the real existing train schedule, based on the probabilistic assessment of which the average daily reactive power consumed by the electric rolling stock is determined. In this case, it is necessary to take into account the power losses in the catenary. The use of unregulated compensating devices is advisable in areas with a constantly present load. When choosing step devices for transverse capacitive compensation, it is proposed to calculate their power based on a probabilistic analysis of the train traffic schedule and current consumption in the inter-substation zone. When the probability of the appearance of a certain number of trains exceeding 50%, the most effective are compensating devices, the power of which is selected on the basis of the average power consumption of all trains without taking into account the time of no load in the inter-substation zone, as well as two-stage devices, the power of the first stage of which is selected according to the current consumption of the two most likely occurrences of the number of trains.