Determination of the Sufficient Inductance of AC Line Reactor at the Input of Frequency Converter

Abstract

 This article discusses the problem of sufficient inductance of AC line reactor at the input of frequency converter. Author provided some simulations for frequency converter loaded by induction motors with different rated powers. For all induction motors the following characteristics of phase current consumed by frequency converter from the grid considered. Instantaneous peak current during the frequency acceleration of induction motor. Amplitude of the current in steady state mode after the end of induction motor acceleration. Instantaneous peak current during additional charge of DC-link capacitance through the shunting contact of charging resistance. Instantaneous peak current when charging DC-link capacitance through the charging resistance - the most stable characteristic, which is practically does not depend on the presence and nominal of the line reactor. It is advisable to demand to inductance of the line reactor, that is, to percent impedance or short-circuit voltage, %, that the considered in computational experiments peak and amplitude values of currents remain not higher than the last above mentioned. It can be stated that with the increase of induction motor rated power, the sufficient value of short-circuit voltage, %, also increases.