Modeling method of alternating current and direct current electric locomotive

Abstract

The invention provides a modeling method of an alternating current and direct current electric locomotive. The modeling method comprises the following steps: calculating amplitudes and phases of a fundamental wave and harmonic waves of the electric locomotive; by taking the amplitudes and the phases of the fundamental wave and the harmonic waves as random variables, calculating probability density functions of the amplitudes and the phases by using a maximum entropy; then calculating distribution functions of the amplitudes and the phases; establishing a first data table corresponding to the amplitudes of the fundamental wave and the harmonic waves and the distribution function and a second data table corresponding to the phases of the fundamental wave and the harmonic waves and the distribution function in matlab; introducing a matlab interface module into PSCAD and receiving the amplitudes and the phases of the fundamental wave and the harmonic waves according to the first and second data tables; and establishing a probabilistic harmonic current source module of the electric locomotive in the PSCAD, wherein the probabilistic harmonic current source module comprises a three-phase voltage source, a traction transformer, a four-quadrant rectifier bridge circuit, a rectifier bridge control circuit and a target output current generation unit. The electric locomotive model established by the invention is relatively close to the actual condition in the aspect of the harmonic waves of the electric locomotive.

Description

technical field [0001] The invention belongs to the field of the influence of an AC-DC electric locomotive on a power grid, and in particular relates to a probabilistic harmonic current source modeling method for an AC-DC electric locomotive. Background technique [0002] With the rapid development of electrified railways, more and more attention has been paid to its impact on the power grid. As a high-power rectification load, electric locomotives generate a large number of harmonics and negative sequence currents during normal operation, which pose a certain threat to the power quality and stability of the power grid. Electrified railway consists of primary power supply system, traction power supply system, electric locomotive and electric vehicle. The primary power supply system mainly includes power plants, regional substations and power transmission lines; the traction power supply system mainly includes two parts: traction substations and traction networks; electric l...

AI Technical Summary

Problems solved by technology

The main reasons are as follows: first, the control method of the internal electrical parameters of the EMU has not been disclosed, and it is difficult to obtain the operating status of the compensation device; second, the harmonics of the locomotive load have random fluctuations due to the influence of line conditions, weather and other factors; third, The influence of the traction network will amplify or attenuate certain harmonics, and the harmonic current flowing into the traction substation is not consistent with the harmonic current injected into the traction network by the locomotive

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