Research Of Torsional Vibration And Control Strategy On Engine-Generator Set In Electric Vehicle

In the thesis, the object is torsional vibration of the electric vehicle auxiliary power system – engine-generator set. The main research of this paper is dynamic simulation modeling for torsional vibration of engine-generator set and the development of control strategy in order to reduce torsional vibration based on the model.According to the structure and related parameters of engine-generator set, by comparing some connection modes, the rubber flexible coupling is selected as the connection mode of the engine and generator. The torsional vibration mathematical model of engine-generator set is established and the moment of inertia, stiffness, damping matrix is determined. Based on the mathematical model, the inherent characteristics are analysed. By analysing critical speed, the vibration reduction effects of the rubber elastic coupling is verified.A dynamic engine torque model, generator and generator controller model is established based on Matlab/Simulink. Combined with the torsional vibration mathematical model of engine-generator set, a system dynamic simulation model is established. Based on the model, the stable conditions and dynamic operating conditions are both analysed. A specific accelerating condition is selected for the simulation. Based on the accelerating condition, both of multi-point switch strategy and single point control strategy for engine are simulated to discuss the torsional vibration. In addition, torque control and current control for the generator are simulated. According to the simulation results, multi-point switch strategy and torque control strategy are selected to reduce torsional vibration.In addition, by changing some accessories’ inertia and replacing flywheel by generator rotor, torsional vibration is analysed, and relevant optimization methods are put forward.