Analysis of the use of soft start in conditions of limited power supply systems

The analysis of soft-start systems of asynchronous motors used on ships is carried out. As a result of the literature analysis, the problem of reducing the quality of electricity in terms of harmonic distortion during operation of thyristor soft-start devices has been identified. It was also determined that the amplitude values of the overvoltage peaks in the general section of the cable network when using a soft starter are almost three times higher than the nominal value of the amplitude of the supply voltage. A simulation model of a soft-start device has been compiled, taking into account operation in power supply systems of limited capacity. The simulation results and their analysis showed the presence of odd harmonics in the network and a significant increase in the total coefficient of harmonic components of the current when starting an asynchronous motor using a soft starter. Thus, during the simulation, it was revealed that the use of soft-start devices in ship systems, along with a decrease in starting currents and voltage drops, negatively affects the quality of electricity. The obtained simulation results will allow for accurate calculation and rational adjustment of passive and active filters used on ships to ensure high quality of electricity.