Active front end technology in the application of a down hill conveyor

Long belt conveyors have always been a challenge for drive and control applications. There are several methods for the drive to be applied. Depending on the geographical conditions, the material to be transported, the fulfillment of the environmental requirements and the operating methods, a different drive system can and must be supplied. This paper describes the drive system for a down hill conveyor which is mounted between the quarry area and the raw material section of the plant. Because of the operational requirements, the drive is to be adjustable in speed, and capable of regenerating the power on the down hill section. A new technique, the so-called active front end technology, was applied and described in detail. All operating processes nowadays are monitored, with sophisticated control systems. The paper gives a good insight to how the control algorithm was applied and is operating. One of the big advantages proclaimed for this technology is that it is "extremely network friendly". The paper shows in detail, what this means, using measurements and analysis in the network. The paper describes, as well, all the environmental fulfilments with the use of a tube conveyor. The content of the paper would not be complete without having a look into the energy balance, from active power taken out of the network, and the regenerative power fed back into the network. It puts an eye, as well, on the aspect of the operating and the life cycle cost.