Study On Parameter Matching And Optimization Of Powertrain System For Fuel Cell Electric Vehicle

The development of Fuel Cell Electric Vehicle(FCEV) is one of the most efficient technologies to solve the problems which were caused by the limit of energy sources and environment pollution.It is the key technology for FCEV to compose electric-electric hybrid powertrain system of fuel cell and auxiliary power source,and study on multi-energy power system parameter optimization, aiming at improving efficiency of the overall hybrid powertrain system. This article take powertrain system design of fuel cell electric vehicle as researching object,focus on parameter matching and optimization of powertrain system for FCEV, and makes parameter matching and optimization of powertrain system for some fuel cell electric bus. The main research process and production are as follows:(1) First of all, summarize the research coments of parameter matching and optimization of FCEV powertrain system,conclude parameter matching and optimization method for the hybrid powertrain system, and point out the study on matching and optimization of FCEV powertrain system is a effective way to improve system efficiency.(2) Comparation and analysis of FCEV powertrain system configuration, obtain that indirect fuel cell hybrid powertrain system structure is more suitable for FCEV. At the same time, two indirect fuel cell hybrid powertrain system structures (FC+B,FC+B+C) are focuslly analyzed based on basic principle of hybrid powertrain system configuration optimization,and analyze characters of typical power sources and technologies of fuel cell hybrid powertrain system, and finally determine the structure of fuel cell system and LiFePO₄ battery pack on consideration of Dongfeng bus design features.(3)For the parameter design of fuel cell hybrid powertrain system,the paper propose the concept of degree of hybridzation(DOH) for electric-electric hybrid powertrain system. The problem of parameter design for hybrid powertrain system is conversed as DOH design on foundation of vehicle dynamics theory, and then produce the method of DOH for fuel cell hybrid powertrain system. Total power, boundary value of DOH and tmotor parameters are obtained based on DOH design for parameters design for FCEV powertrain system.(4) On the basis of introduction of genetic algorithm and hybrid algorithm, and according to parameters optimization problem of fuel cell hybrid powertrain system, built a non-linear mathematical model with vehicle dynamic constraint and optimal fuel economy target, and bring up optimal target, optimal variables and constraint function.Meanwhile hybrid genetic algorithm is adopted to solve optimization problems considering inadequacies of the basic genetic algorithm, and optimization results are significantly improved comparelly, verifing effectiveness of hybrid genetic algorithm. At last,the impact of DOH and SOC value on optimization objectives is analyzed.To sum up, this thesis's study on configuration optimization, parameters matching and optimization for FCEV powertrain system provides a theoretical guidance for the next physical experiment and real vehicle development with certain sense of reality. In particular, parameters design based on DOH for FCEV powertrain system, and application of hybrid genetic algorithm optimization in hybrid powertrain system offer certain reference for parameters matching and optimization for other similar hybrid powertrain system.