Objective: To analyze the loss of power in cable wires of the railroad alternate current catenary system both in the presence and in the absence of equalizing gear in the middle of inter-substation zone, taking into account train traffic. Methods: Passing of one train and two others following each other along the inter substation zone was considered. The comparison of power losses in cable wires of the catenary system was conducted both in the presence and in the absence of equalizing gear. The difference of losses was determined. The simulation of one train passing along the inter-substation zone was fulfilled in the environment of MATLAB-Simulink. Results: It was shown, that the average values of power losses in cable wires of the catenary system were equal with one train passing along the inter substation zone both in the presence and in the absence of equalizing gear. In case of two trains passing along the inter substation zone, following each other with equalizing gear capacity, selected by the average idle current of one train, the losses of power in cable wires of the catenary system decreased with equalizing gear installation, however, in that case, reactive power was partially compensated. The simulation of one train passing along the inter-substation zone in the environment of MATLAB-Simulink, taking into account power losses in the catenary system and railroad substations resistance, substantiates the assumptions taken in the analytical estimation. Practical importance: Despite the fact, that active development of filter compensating devices is conducted in the sphere of reactive power compensation on the railroad transport, capacitor banks are still used on alternate current railroads. The given study is aimed at the improvement of the current procedure of selecting optimum power of equalizing gears.