Energy Efficiency Optimization Control Of Diesel Engine Equipped With E Turbo

Electrically assisted turbocharging(eTurbo)can effectively solve the contradiction among the engine power,lightweight and compactness.It is an important means for the electrification and intelligentization of internal combustion power system,and has been highly valued in the field of internal combustion engine.Diesel engine,equipped with e Turbo,is a highly dynamic and strong coupling system with a wide operating range and high control freedom.The problem we need to solve is how to realize the energy-saving,strong and clean operation of diesel engine equipped with e Turbo under wide and variable working conditions.In this paper,the heavy-duty diesel engine is taken as the research object to reduce energy consumption.The research is conducted from two aspects of intake circuit tracking and thermoelectric power distribution,in an attempt to explore new methods for energy efficiency optimization control of electrically assisted turbocharged diesel engine.Firstly,a complete prototype platform for electrically assisted turbocharged diesel engine system is built through the hardware integration of e Turbo and air system.The dilution effect of e Turbo on recirculated exhaust gas and the overshooting effect of intake components is revealed,and the suitability of intake oxygen concentration as the controlled variable of the intake circuit in system-oriented optimization control of energy efficiency is demonstrated.It is found that the oxygen concentration in the exhaust gas increases by 65.56% and the oxygen concentration in the intake air overshoots by 1.88%.The correlation coefficient between the NOx concentration in the original emission and the oxygen concentration in the intake air reaches 98% when e Turbo is enabled to assist air charging.Secondly,a simulation platform for comprehensive energy efficiency analysis of electrically assisted turbocharged diesel engine system is built by means of data modeling and mechanism modeling,which is composed of turbocharger,motor,battery,heavy-duty diesel engine.Aiming at the overshoot of intake components under e Turbo assisted air charging and the dynamic optimization of thermoelectric power allocation under changing conditions,a two-stage control architecture for high-level intake loop tracking control and low-level thermoelectric power allocation optimization is proposed.A cost function is designed in a weighted manner,which takes the system's dynamic performance,emission performance,operating efficiency,battery SOC and other conditions into consideration.An optimization control algorithm of energy efficiency,combining active disturbance rejection and model predictive control,has been developed.Simulation results show that the algorithm can reduce the cumulative tracking error of boost pressure and intake oxygen concentration by 86.59% and 7.42%respectively under the FTP-75 driving cycle.Also,the operating ratio of small openings(less than 40%)of the turbine nozzle ring can be reduced by 90.48%.The engine fuel consumption is reduced by 2.2%.Finally,a simplified method for the optimization control algorithm of energy efficiency is proposed with the help of extended state observer in order to solve the problem of real-time operation.The method can effectively remove the non-linear part of the dynamic equation in the predictive model and make up for the serious prediction error after the model simplification by the excellent observation ability of the internal and external disturbance.As a consequence,different simplification processes for the optimization control algorithm of energy efficiency are completed.Then,the execution efficiency is tested on a LABCAR-based hardware-in-the-loop platform.The results show that the running time of the completely simplified version of the optimization control algorithm is shortened to 9.87 ms,and the CPU load is reduced by 17.5% in the dual-core scheduling mode where the engine speed is 3000r/min.In summary,the optimization control algorithm of energy efficiency proposed in this paper,which combines active disturbance rejection and model predictive control,solves the energy-saving,strong and clean operation of the diesel engine equipped with e Turbo under wide and variable working conditions.Also,the algorithm has laid an important foundation for the industrial application of the electric assisted turbocharging technology.The idea of this paper can also be used for reference to solve the complex coupling problem in multi-source energy system.