STUDY OF AN ALTERNATIVE METHOD OF SOFT START OF ELECTRIC MOTORS OF MECHANISMS WITH LARGE MOMENTS OF INERTIA

This paper explores an alternative method for smoothly starting electric motors for machines with heavy shaft loads and inertia moments, such as pumping units. The starting mode of high-power electric motors is known to involve complex transient processes. The primary problem arises from high starting currents, which can lead to a number of issues, including winding heating, starting device failure, noise and vibration, and voltage sags in the grid. Therefore, addressing these issues is a pressing issue today. Scientists and engineers are proposing various methods and means for smoothly starting such machines. One promising approach is to use a frequency converter with a current inverter. This device operates as a current source that can strictly limit the electric motor current during starting mode, eliminating negative consequences. The article presents the results of an analysis of devices based on a current inverter manufactured by various international companies. It also presents the results of a computer simulation of a pumping station power supply system, where a current inverter was used to start the pumping units. The Simulink package from MATLAB was used for modeling. This system offers all the necessary tools for structural modeling and simulation of complex technical systems. Furthermore, the paper presents the results of a comparison of the impact of different starting modes on the power supply system of a pumping station. It is shown that with a soft start, voltage sags in the network do not exceed standard limits. Voltage sags caused by direct starts of high-power pumping units lead to negative consequences for other components of the power supply system, including adjacent units, electric motors at other stations, and all consumers of electrical energy in the system as a whole. To address all of the above issues, this paper proposes an alternative method for starting pumping units.

electric drive, current inverter, power supply system, synchronous motor, pump unit, starting mode, computer modeling, soft start.

2026-08-24