Analysis of dv/dt Filter Parameters Influence on its Characteristics. Filter Simulation Features

Abstract

The analysis of characteristics (including Bode diagrams) of the EMC output filters for a frequency converter is carried out by means of computer simulation. The $dv/dt$ filters with various parameters, including different schemes of damping resistors connection such as parallel connection to inductance in a series branch of the filter and the series to capacitor connection in a parallel branch of the filter, were considered in the steady-state operation mode at 2.5 kHz carrier frequency of voltage pulse-width modulation and 50 Hz frequency of fundamental harmonic of induction motor feeding voltage. The case of the $dv/dt$ filter without damping resistors is also considered. Losses in filters are taken into account. The authors make the conclusion about the need to take into account the parasitic parameters of capacitors: equivalent series inductance; equivalent series resistance; equivalent parallel resistance, accounts for leakage current in the capacitor; Zener diode, models overvoltage behavior, in case of the filter without damping resistors.