Industrial processes susceptibility in relation to their environment

The perfection of sine wave power supply is always assumed, that is to say, voltage power supply has 50 or 60 Hz perfect sinusoidal waveform and its root mean square value is the rated one. It is known that electrical companies cannot supply this perfect kind of waveform, though in normal conditions they are within the limits imposed by regulations. Disturbances are generated under abnormal conditions such as lightning on a power system or the opening of a switch. These disturbances can affect electronic equipment. The equipment that requires a constant voltage is particularly affected. In this paper, the results of several tests accomplished are shown. The tests were carried out with linear power supplies, personal computers and programmable logic controllers (the last ones have switched power supplies) by means of the voltage sags generator designed by the Electrical Engineering Department of UPC. The latest technologies used in inverters of adjustable speed drives (IGBT for half power) have considerably increased bearing damage and dielectrics breakdown in induction motors due to use conditions of these converters. This fact has contributed to increasing the research to establish solid theories which explain these phenomena and help to find solutions for them. Problems related to voltage feeder disturbances also remain unsolved. This aspect is becoming more and more important for the users, since it is the main cause of interruption in multiple industrial processes. The aim of this study is to establish theoretical and experimental bases that help to understand and solve those problems arising in industrial applications, and also to provide users with useful tools for the correct operation and maintenance of the installation.