Research And Implementation Of Sliding Mode Control For DC/DC Converter Of Fuel Cell

In recent years,as the rapid development of new energy power generation technology,fuel cell has gradually become a research hotspot in the field of new energy.However,drawbacks of the fuel cell,such as the soft output characteristics and slow dynamic response,the electric energy can only be used after conversion of the special DC/DC converter.High performance DC/DC converter has become one of the most urgent problems to be solved at present.This thesis proposed to research control strategies of the DC/DC converter of fuel cell and aimed at improving the dynamic performance and robustness.The main contents are as follows:A kind of topology of the DC/DC converter of fuel cell was proposed.First,the characteristics of the fuel cell were analyzed.With the goal of low input and output current ripple and high step-up ratio,a boost topology composed of two level circuits was designed.The first stage is two-phase interleaved parallel Boost converter,the second stage is phase shifted full bridge.Then the state space average model is established,which lays the foundation for the design of sliding mode controller.Based on an incremental sliding plane,a sliding mode controller of the DC/DC converter was designed.Inductor current and output voltage has been taken as control targets of the first stage.A sliding mode plane consisting of the proportion and the integral of its errors was constructed for Boost converter.Based on it,a sliding mode controller was designed.Output voltage has been taken as control target of the second stage.Based on an incremental sliding plane which consisted of the proportion,differential and integral of its errors,a sliding mode controller was designed for phase shifted full bridge.The accessibility,existence and stability of the controller were analyzed,and the control parameters were designed.The effectiveness of the method was verified by simulation.Based on double integral sliding plane,an adaptive sliding mode controller of the DC/DC converter was designed.In order to improve the dynamic performance,steadystate accuracy and robustness of sliding mode controller,a double integral sliding plane was proposed on the basis of the incremental sliding plane,and a sliding mode controller and control parameters were designed.At the same time,an adaptive parameter was proposed for the chattering problem,and an adaptive sliding mode controller was designed.The simulation proved that the controller can further improve the performance of the DC/DC converter.The experiment platform of the DC/DC converter of fuel cell was constructed,and the proposed control strategy was experimentally verified.Based on the experimental platform,input ripple,soft-switching implementation of the DC/DC converter of fuel cell and the realization of sliding mode controller were analyzed.The experimental results shown that the adaptive sliding mode controller based on the double integral sliding plane has better dynamic performance and robustness to the load.