Active torsional vibration control of reciprocating engines

In modern fuel injection systems for reciprocating engines non-uniform cylinder-wise torque contribution is a common problem, causing increased torsional vibration levels of the crankshaft and stress of mechanical components. In this paper a method for reducing the torsional vibration of the crankshaft is presented. This technique balances the cylinder-wise torque contributions by utilizing the measured angular speeds of the crankshaft system. The proposed method is successfully tested on a 6 MW common-rail diesel engine-generator set. The torsional vibration levels of the relevant frequencies were reduced with up to 90% and a significant reduction of the thermal load of the flexible coupling was achieved.