Harmonic filters and power factor compensation for cement plants

Due to the large installed electrical power and the large number of electric drives in cement plants power factor compensation has always been an issue. However, harmonic filters as advanced type of power factor compensation have become increasingly important because more and more variable speed drives that produce harmonic disturbances have been installed during the last years. Furthermore, the awareness for harmonic distortions has got stronger as well. For the design of harmonic filter and power factor compensation installations several approaches can be taken. The paper describes different concepts and their advantages. This is done for new green field installations as well as for revamp projects. It also highlights areas where problems can occur and which points need to be paid attention to when additional drives are installed, parts of a cement plant are modified or when cement plants are expanded. Problems that occurred in cement plants are briefly analyzed. The root cause of the problems is explained, solutions are discussed, and the improvement of the behavior is shown. Furthermore, the paper gives guidelines what can be checked to find out whether there is a problem with harmonics and how such problems can and should be analyzed.