Research On Energy Management Strategy Of Parallel Hybrid Power System

With its energy-saving and emission-reducing features,the development of Parallel Hybrid Electric Vehicles（PHEV）is one of the solutions to effectively alleviate the global energy crisis and environmental pollution problems.Considering the characteristics of less pollutants and low fuel consumption of PHEV,parallel hybrid power system has been deeply studied and developed,and its energy management strategy has become a popular and key topic of research in the automotive industry.In this thesis,the energy management strategy of parallel hybrid power system is studied.The main work is as follows:1)To classify and summarize the arrangement forms of hybrid power system.The structure and operation mechanism of parallel hybrid electric vehicle are studied and analyzed.At the same time,the realization principle of each key component of parallel hybrid electric vehicle is expounded,and the mathematical model of the whole vehicle and each component of parallel hybrid electric vehicle is deduced.Then,a parallel hybrid electric vehicle simulation model is built in MATLAB/ADVISOR environment to provide a verification platform for energy management strategy and multi-objective optimization of the power system.2)While analyzing and classifying the operating modes of parallel hybrid vehicles in detail,two classical fuzzy controls of Mamdani type and T-S type are analyzed theoretically.Based on the working mode of parallel hybrid vehicles and the experience of experts,a dual-input-single-output fuzzy controller is established with the vehicle demand torque(T_{re q}),power battery as the input and the starting torque value（_eT）as the output.The energy management strategy of parallel hybrid fuzzy logic control is designed.Then,under the UDDS and NEDC road cycle conditions,the fuzzy logic control energy management strategy designed in this thesis is verified.At the same time,the vehicle simulation results are counted and compared with the rule-based energy management strategy.3)In response to the problem of dealing with the optimization problem of parallel hybrid power system design,the multi-objective problem is usually reduced to a single-objective problem by setting weights,but the mutual influence among the objectives is not considered,which makes it difficult to reflect the real situation of the optimization objectives and thus suffers from the problem of low-quality solutions,so a new multi-objective optimization method based on MOSMA is used to optimize the hybrid system.Then,a three-objective optimization mathematical model with the objectives of fuel consumption,CO emissions,HC and NOx emissions as the sum of the three objectives was developed.Six parameters that dominate the performance of the hybrid powertrain are selected as optimization variables and are optimized by dynamic performance and battery charge state balance constraints.In this thesis,ADVISOR is used as a simulation platform to simulation and verification,and pollutant emissions and fuel consumption under three energy management strategies are analyzed and compared.The results show that compared with the rule-based strategy and the fuzzy logic control strategy,the new multi-objective optimization method based on MOSMA designed in this thesis can effectively solve the multi-objective optimization problem of the energy management strategy of the parallel hybrid power,and reduce the fuel consumption and pollutant emission under the premise of ensuring the dynamic performance.