Research On The Applicability Of Diesel Electric Power Pack

There are two layout modes of DMUs,power centralization and power decentralization.The advantage of power decentralization is fully reflected in high-speed railway.Diesel Electric Power Pack,which is a compact integrated diesel generator set,is widely used in distributed power DMUs.When Diesel Electric Power Pack is applied to the DMU,the load mutation of Diesel Electric Power Pack may be caused by the traction system under the variable working conditions.However,when the diesel engine has a certain adaptability,this mutation may cause the diesel engine emission not reaching the standard or the diesel engine even stopping.In view of this problem,this paper studies the methods to improve the applicability of the system in the design and application of Diesel Electric Power Pack,and provides a series of solutions for the development of high-performance DMUs.In this paper,Diesel Electric Power Pack of excitation synchronous generator applied in a DMU is taken as the research object.By analyzing the application system,system structure and operation control mode of Diesel Electric Power Pack,it is concluded that the essence of the applicability problem of Diesel Electric Power Pack is the change rate of the diesel engine load.Reducing the change rate of the diesel engine load in the application of Diesel Electric Power Pack as much as possible can improve the applicability of Diesel Electric Power Pack.This paper studies how to improve the adaptability of Diesel Electric Power Pack from the following aspects: Firstly,when the change rate of fuel supply needed to be increased exceeds the limit,the diesel engine control system applied to Diesel Electric Power Pack sends a power limit request signal to the generator excitation system and traction system,which requires the excitation regulation system and traction control system to adjust the power rise rate in time to improve its applicability;Then,according to the dynamic and static performance requirements of the generator excitation system,a fuzzy sliding mode composite control strategy is adopted,and the excitation current change rate limit is added in the generator excitation control to reduce the change rate of diesel engine load when the load changes suddenly.Finally,from the point of view of Diesel Electric Power Pack system structure,the measures of adding buffer inductance and energy storage link in the middle DC link are taken to deal with the sudden change of diesel engine load caused by short-term load mutation;From the aspect of diesel engine gear control,the applicability of Diesel Electric Power Pack is improved by adopting slope signal instead of step signal to control the speed increase of diesel engine;From the perspective of traction system development,the load mutation can be reduced directly by limiting the change rate of traction,so as to improve the applicability of Diesel Electric Power Pack.Matlab/Simulink software is used to build the simulation model of Diesel Electric Power Pack system.The simulation results show that the measures proposed in this paper can improve the applicability of the internal combustion power pack system.