Harmonic Penetration Analyses for DC-Link Frequency Converter Drive Systems by Considering the Motor-Side Converter as an Ideal Current Generator

Nowadays increasing attention turns to the harmonic penetration analysis of the alternating voltage network connected devices operating with pulse width modulation (PWM). The PWM operation causes high frequency current injection to the grid (at the frequency range: 1kHz to 100kHz, depending on the power and the structure of the device). However, devices are now rolling out, that are infected by these current components, for example: power line communication (PLC) devices, smart metering devices, etc. It is very difficult to analyse such high frequency harmonic components with measurements. Therefore, the simulation analyses of the PWM devices harmonic penetration are revalued. These are cost efficient and fast. This article is dealing with the harmonic penetration analyses of alternating voltage network connected DC-link frequency converters equipped with active rectifier. In our study we were focusing on the variable frequency drive (VFD) of squirrel cage induction motors (SCIM). Simulation models of the motor and a DC-link frequency converter were built in time domain. The main purpose of this paper is, to study whether the effect of the motor-side converter of the VFD and the motor can be neglected for the harmonic penetration analyses of the DC-link frequency converter.