The Research Of Model Order Reduction Of Electro-mechanical Transmission In Terms Of System Controlling

Electro-mechanical transmission system is a complex and automatic system under thecontrol of the coordination of multiple power sources. Researching on model reductiontechnology of electro-mechanical system based on experimental data andelectro-mechanical transmission mechanism is playing an important role in improvingnumerical simulation speed and real-time controller designing of the electro-mechanicaltransmission system.In this paper, model reduction methods of linear systems and nonlinear systems arestudied. For different mathematical models, the reduced order system, which isapproximated to the original system, is obtained by using different model reductionmethods based on the mechanism of the original system. And the reduced order system isverified by numerical simulations.According to different control purposes, different models of the planetary couplingmechanism of varying complexity are established. For different models, the proper modelreduction methods are selected to reduce the order of the planetary coupling mechanism ofthe electro-mechanical transmission system. And the reduced order system is verified bynumerical simulations. Numerical simulations show that the responses of reduced ordersystems are within the allowable error bound in terms of both time domain and frequencydomain. The reduced order system has a lower order with respect to the original system,and has higher computational efficiency.By using modular modeling method, the engine model is divided into6subsystems,turbo model, compressor model, the intake pipe model, the intercooler model, cylindermodel and the exhaust pipe model. The nonlinear model of the engine is established, andthe nonlinear state space expression of engine model is established. The order of thenonlinear engine model is reduced by moment matching. Numerical simulations areconducted to verify the effectiveness of reduced order system.On the platform of MATLAB/SIMULINK, a robust controller of the engine isdeveloped based on the reduced order system. By using the reduced order system thatretains the characteristics of the original engine system, a robust PI controller is developedand verified. A PID controller is also developed, and the performances of the PID controllerand the robust PI controller are compared under different dynamic conditions of the engine.Simulation results show that the robust PI controller has a better control performance. By using modular modeling method, a vehicle simulation model, which consists of theengine model, the motor model, the battery pack model, the planetary coupling mechanismmodel and control unit module, is established. By using the PID controller and the robustcontroller based on reduced order model respectively, the dynamic performances of theengine is controlled in the accelerating condition of the electro-mechanical transmissionsystem to maintain a steady output of the engine in the dynamic operating conditions. Thegood dynamic performance of the electro-mechanical transmission system is ensured. Theeffectiveness and the control performance of the controller based on the reduced ordersystem are further verified.