Design On The DC/AC Power Conversion For Fuel Cell Stand-Alone Generation System

Fuel Cell is a device which can transform chemical energy stored in fuel and oxidizer directly into electric energy. It is a green energy of high efficiency. Fuel Cell generation system is regarded as one of the most promising energy sources in the field of distributed power system. It has various advantages such as easy-to-install, high efficiency of power generation and density, free from natural conditions, environment friendly, stability and reliable operation, so it is regarded seriously by more and more people.In the small and middle scale Fuel Cell generation power system, the output voltage of the FC is not always very high and varies largely as the load changes. Therefore, power converter is essential in the Fuel cell generation system. Fuel Cell should be connected with a power converter which can boost the voltage of the FC and stabilize the voltage of the output of the power converter. The power converter also can transform the unstable DC into required DC/AC . And this paper mainly studies the power converter of the fuel cell generation system.This paper first introduces the background of selection of this subject, analyses the working theory of PEMFC and gets the output performance equation of PEMFC. Then according to the output performance of PEMFC, this paper compares different topologies of DC/DC converter and designs the power converter of 5kVA with a detailed hardware design and control software design. When 30-80V DC is inputted, the power converter transforms it into 220V/50Hz AC. Then , the paper analyses the loss distributing, and puts forward some methods to improve the efficiency. Finally, the paper shows the experiment results of the converter to prove its feasibility and rationality. The efficiency of the power converter is about 83%.This paper studies the power conversion technology of Fuel Cell generation system on 220V/50Hz. It has important significances to improve the Fuel Cell power generation system, solve the contradictions between energy and the environment, enhance the power supply reliability of communications and other departments in the future.