Method for calculating accumulated power of multiple trains of traction substation of electricity supply system of urban rail transit

The invention relates to a method for calculating the accumulated power of multiple trains of a traction substation of an electricity supply system of an urban rail transit. The method comprises the following steps: obtaining the power distribution of a train through simplified traction calculation, and obtaining the power distribution of n trains through permutation and combination; obtaining the number of the trains driven by the traction substation and the probability thereof through the electricity supply radius of the traction substation, the average travelling speed of the trains, the departure interval and a number probability integer method; obtaining the power distribution of the traction substation by combining the power distribution of the n trains and the number of the trains driven by the traction substation and the probability thereof. The method disclosed by the invention only uses as few as basic parameters which are easy to obtain, so that complicated tide calculation of mixed alternating and direct currents of the traction substation is avoided, at the same time, the largest power distribution, 95% of power distribution, and the average power of the traction substation are obtained, and the error of a calculation result is within an allowable scope, so that the method is suitable for the practical application of engineering. The power of the traction substation, which is obtained through calculation by the method disclosed by the invention, is used, and the harmonic assessment knowledge is combined, so that the level of the harmonic emission of the traction substation can be assessed.