Research On Optimization Management And Control Algorithm For Fuel Cell Hybrid Energy

With the characteristics of non-pollution, low noise, high energy conversion efficiency and high energy density, fuel cell is used as the main power source of the electric vehicle. However, fuel cell cannot absorb the braking energy, an auxiliary energy is then equipped. With quick charge and discharge, high power density and long life, ultra-capacitor has received wide attention. How to optimize the management of hybrid energy and prolong the service life of the fuel cell has become a hot research topic.This paper focuses on the energy management and control algorithm of hybrid energy. Firstly, the overall system structure is analyzed, where the fuel cell is connected to the DC bus by a unidirectional DC/DC converter, and ultracapacitor is connected to the DC bus through a bidirectional DC/DC converter. The equivalent models of the fuel cell,the ultra-capacitor and the DC/DC converter are established, and the PI controller of DC/DC converter is designed. Secondly,a fuzzy energy management controller is designed, selecting the demand power of the load and the state charge of ultra-capacitor as the inputs and the output power of the fuel cell as the output. In order to achieve a more reasonable power distribution of fuel cell and ultra-capacitor and reduce the fluctuation range of the fuel cell power output, the membership functions of the fuzzy controller are optimized by using the genetic algorithm, and the distribution ratio of the output power of the hybrid energy is further regulated.The simulation results show that, the power output is adjusted by the energy management controller with the change of demand power of the load,a reasonable distribution of power has been achieved. After optimization, the energy management controller makes the power output of the fuel cell change more smoothly.