A Novel Control Strategy Applicable for a Dual AC Drive With Common Mechanical Load

The use of a dual electromechanical drive is a well-established and an efficient solution especially when high-power systems are considered. A very important requirement in such systems is the accomplishment of a load balance between the two drives in order to prevent a potential overloading of the one drive in relation to the other one. Additionally, the appearance of mechanical oscillations must be avoided as it will be catastrophic for the mechanical equipment, particularly in the case of mechanical resonance. In this paper, a general analysis of the existing control strategies already used in dual ac drives is being realized first, and a new hybrid control method is proposed based on the need of equal load and power distribution between the two drives. The efficiency of the proposed method is examined for a cement kiln which is a typical system whose large size and imperative uninterrupted operation enforce the use of such a dual drive. A theoretical analysis is being realized developing a corresponding mathematical model and using Matlab/Simulink. Finally, the proposed method is verified using a low-power laboratory system which has been appropriately designed to experimentally simulate a dual drive cement kiln operation.