An online optimal control algorithm for electrically assisted turbocharger(eTurbo) was proposed for a diesel engine equipped with eTurbo and high pressure exhaust gas recirculation(EGR) to achieve a multi objective optimization: the minimum fuel and power consumptions and the minimum tracking error of intake oxygen concentration. According to the target values of intake oxygen concentration and boost pressure

EGR valve opening and power for compressor were adjusted based on the active disturbance rejection method. The compressor power demand was distributed between turbine and motor based on the model predictive control(MPC) to realize the best trade off among engine fuel consumption

electric consumption

and EGR mass flow. The results of the simulation based on the GT-SUITE/Simulink platform show that under the FTP-75 driving cycle

compared with the traditional turbocharged diesel engine

the boost pressure tracking error of the eTurbo diesel engine is improved by 87.20%

the intake oxygen concentration tracking error increases by 1.93% and the fuel economy is improved by 0.82%

verifying the effectiveness of the proposed optimal control algorithm.