Coupling analysis of torsional vibration, Speed control system and advanced injection angle of low speed diesel engine

For general simulation and evaluation of torsional vibration of low speed diesel engines, the parameters of PID controller and advanced injection angle are always assumed to be constant. The influences of PID controller and advanced injection angle on torsional vibration of low speed diesel engines are always not considered. However, both of these two factors would affect the excitations of torsional vibration directly. Also correspondingly, once severe torsional vibration occurred, transient rotating speed would be varied and then affect the speed control system. For studying such coupling effect of engine shafting system and control system, in this paper, a coupled crankshaft torsional vibration simulation model with both speed control system and advanced injection angle considered are established. The influences of different parameters of PID controller and advanced injection angle on both excitations and torsional vibration of the shafting system are analyzed and illustrated. The results indicated that the PID controller and advanced injection angle have a significant influence on the combustion performance and the excitation torque applied upon the shafting.