Method for determining a characteristic for the quality of a network supplying a frequency converter

摘要

The method involves measuring an intermediate circuit voltage (UZK) and determining a network-side intermediate circuit current (iZKnetz) during the operation of a frequency converter (2). These measuring quantities are compared with preset operating values of the converter. The frequency of the higher and lower measuring quantities is determined and converted into a characteristic number for the quality of a feeding network (18).