Improvement of the frequency converter’s equivalent circuit when calculating non-sinusoidal modes

Abstract

The issues related to modeling a variable frequency drive are discussed in the article. The authors were faced with the task of determining the influence of the drive load on the parameters of its equivalent circuit. An unambiguous dependence of the drive load on the value of the current’s harmonic components is revealed. Namely, the smaller the load, the greater the value of the current’s higher harmonics. It has been established that disregarding drive loading can lead to a 19% error in modeling the frequency converter current consumption. It is shown that the results of the study can be extended to a wide range of drives in terms of power, since all calculations were performed in relative units.