Energy interaction of two-link converters of a multi-motor drive with mains supply

Abstract

It is known that the total power electrical loads consume from the mains is the sum of their two components – active and reactive. Most electric drives of modern industrial enterprises consume up to 40% of reactive energy in relation to the total energy. This results in an increased full power consumption thereby increasing the load on the supply mains. Modern electric drives are built as follows: supply mains – rectifier-direct current link-inverter – asynchronous motor. The total power consumption is at the "mains-rectifier" interface, where the required active power factor of the converter can be formed. The higher the active power factor, the lower the reactive component in the total consumed energy. Thus, the paper proposes a solution to the problem of building highly efficient converting devices for powering electric motors with the required power factor. In particular, the paper discusses possible increase in the power factor of the electric drive mains input with two-link frequency converters based on active (controlled) rectifiers with current and voltage inverters. The author proposes new ways to control active rectifiers based on the use of AC rectifying devices with fully controlled GTO, GCT thyristors, as well as pulse-width control IGBT transistors. The paper offers options for the construction of these rectifiers and the results of modeling the proposed control methods, confirming a decrease in the passive components of the mains current, and, as a consequence, an increase in the mains input power factor. The simulation results were obtained in MathLab 10, and are the basis for confirming the method of increasing the active power factor at the mains input of a controlled two-link frequency converter.