Harmonic composition of the rectified current in traction substations when using different rectifier circuits

The article describes harmful effects of the magnetic field on the electrical staff from the sources, which are rectifier transformers at converting electrical substations. It gives an analysis of the harmonic structure of the rectified current when used in the traction substations with various circuits of rectifier transducers. It is shown that the rectifier transducer is the source of the harmonic components of the alternating current and has a range of magnetic intensities, which harmful effects on staff have not been studied so far. It has been shown that lowering the level and composition of the higher harmonic components of the primary current and power network is promoted by the use of multi-pulse converters in traction substations. The article shows basic analytical relations that allow calculating the levels of harmonic components of the currents and the parameters of the induced magnetic fields when a primary AC of a rectifier transducer has sinusoidal nature. The calculation of the magnetic field intensity caused by harmonic components of the rectified current of sinusoidal nature shows that in some cases there are exceeded maximum values of the magnetic field (MF) of 50 Hz. In order to preserve the life and health of electricians servicing electrical traction power supply, it is necessary to monitor the workplace MF intensity levels and timely inform the staff about the high MF levels.