Optimization Research For Hybrid Power System Of Fuel Cell Vehicles Based On Multiple Model Control

Internal-combustion engine incarnates the distillate of human wisdom in the full century, but the fatal weakness of it is to cause pollution. As the petroleum resource in the world has dried up day by day, internal-combustion engine can hardly breaks away from the passive complexion. In consideration of energy saving and environment protection, to develop Electric Vehicle is indispensable. Fuel Cell Electric Vehicle is a kind of high-efficient, clean and non-emission automobiles, which originated in the 1970s, and became the research focus in recent ten years. The main power energy source of fuel cell electric vehicle is proton exchange membrane fuel cell, and power system structure and energy management strategy is the focus technology of the entire research field of fuel cell electric vehicle.This article took the power system of fuel cell electric vehicle as researching object under the background of developing fuel cell electric vehicle. Analysis of electric-electric hybrid power system structure of Fuel Cell Vehicle, the basic model of hybrid power system was established based on the Advisor platform. The power system energy management strategy based on multiple model switch control was brought forward and simulation results would prove that the strategy was very effective to the whole system. The main research production and innovation point are as follows:(1) The electric-electric hybrid power system structure of Fuel Cell Vehicle was designed, that is, the whole power system included the fuel cell system, the LiFePO₄ battery pack and the ultra capacitor pack. Analysis of every energy source characteristic and configuration of power system, the electric-electric hybrid power system structure was optimized, and the vehicles basic performance index and power system crucial parameter was designed. Based on the Advisor platform, the each components model of power system was established by the modular way, including the fuel cell system, the LiFePO₄ battery pack, the ultra capacitor system, the DC/DC converter and the DC brushless motor. Based on the Advisor platform, the basic model of electric-electric hybrid power system was established on the basis of researching vehicles body model.(2) Because there were not one single model and control method which could describe the whole power system, the power system energy management optimization strategy based on multiple model switch control was designed. There were various working modes to the electric-electric hybrid power system, which included start-up mode, accelerating or climbing mode, cruising mode and braking mode, and the energy management target and power distribution method of respective working mode was researched and designed. By applying the fuzzy supervised rule, the power system energy flow management strategy based on multiple model switch control was designed.(3) The dynamic response soft characteristic of fuel cell system will result in poor dynamic performance, so the integration optimization methods combining power system energy management and fuel cell system control were brought forward. In the accelerating mode, the neural network predictive control strategy of fuel cell system output power was adopted, and the simulation and experimentation results proved that the system dynamic performance could be improved by the predictive control strategy.(4) To compare other energy management strategy of Fuel Cell Vehicle power system with energy management strategy based on multiple model switch control proposed on this article, the simulation system was established. The simulation and experimentation results were presented, which indicated/showed that vehicle fuel economy index decreased 3.3% compared with power following control strategy by applying the power system energy management strategy based on multiple model control. The concept of hybrid ration about power system was proposed, and the power system structure and hybrid ratio was further optimized on the basis of simulation of power system with different structure and hybrid ratio.In a word, this article took the electric-electric hybrid power system structure and energy management strategy of Fuel Cell Electric Vehicle as optimization object, and proposed one kind of three energy source hybrid power system structure, and adopted power system energy management strategy based on multiple model switch control. In the end, the simulation results had indicated this strategy's validity, which could provide a kind of roadway and reference on the aspect of optimizing power system structure of fuel cell electric vehicle, system configuration and control strategy.