Method for determination of the risk to disturbance-free operation of a frequency converter

Abstract

The invention relates to a method for determining the chance of a disturbance-free operation of a frequency converter (2) connected to a feeding network (18). According to the invention, during the operation of said frequency converter (2), an intermediate circuit voltage (UZK) is continuously measured and a network-side intermediate circuit current (iZKmains) is continuously determined; these measuring quantities are compared with pre-determined operating values of the frequency converter (2), and quantities which are higher or lower than said values are respectively stored; and the frequency (Hij) of said higher and lower measuring quantities is determined and converted into a characteristic number for the quality of the feeding network (18). As said characteristic number decreases, the chance of a disturbance-free operation of the frequency converter (2) increases. In this way, a frequency converter (2) is able to detect the risk of appliance disturbance or failure as a result of network disturbances before the operation is interrupted.

Dependencies are inferred from the claim text.