Starting of drives in the cement industry requirements, methods and solutions

The times are definitely over when in the cement industry only the DC drive was applied in the case when an adjustable speed drive was needed and a synchronous, a wound rotor motor or a squirrel cage induction motor, in case of fixed speed drive. Nowadays a quiet large number of different technologies with different physical behaviors are available and applied. The requirements for starting the load machines came in the mean time due to continuously increased sizes of the plants different and consequently more complex as well. The starting torque, the inertia, the starting time and the condition of the power supply of the network feeding line has to be regarded scrutinized with the same precise behavior as the selection of the drive. Only if the both aspects are fulfilled, the drive physical behavior on one site and the requirements of the load are known on the other site, it results in successful starting and operations of the equipment. But not only the starting process in terms of selection and dimensioning is a challenge, in case of bypass necessities the dimensioning of the drives turns into a range where one really has to know what to do. The intention of the paper is to raise the awareness of the starting requirements, to show which kind of starting methods with different technologies are available today and give approved solutions for all the cases.