Harmonic characteristics of direct crossing locomotive connected into photovoltaic power grid

To investigate the harmonic characteristics of electric locomotives connected to a photovoltaic (PV) power grid based on the actual parameters of a region in Tibet, this paper establishes a simulation model of an electric power grid, including PV and electric locomotive. First, theoretical analysis is conducted to study the harmonic characteristics of electric locomotives and PV power stations. On this basis, we built the MATLAB model to analyze the influence of dynamic working conditions on the locomotive and PV sides on the harmonic characteristics of the power grid. Through the first, second, and third working conditions, a simulation analysis is performed to examine the harmonic characteristics of an electric locomotive when connected to the grid, which includes a PV power source. The results show that the grid side current, including PV and electric locomotive, has a three-phase equilibrium phenomenon, and at the same time, the grid side current harmonic characteristics, including PV and electric locomotive, are mainly reflected in the 17, 19, 21, 23, and 25 frequency odd harmonics.