The Research And Development Of 1KW Grid Connected Fuel Cell Inverter

Nowadays, due to the lack of common energy, pollution and requirement of high quanlity grid, researchers have been paying more and more attention to the development of renewable energy and distributed power generation system. As an indispensable part of distributed power generations, inverter has become a hotspot of globle energy research.Thanks to its high effiency and low pollution, fuel cell has been an important aspect in all kinds of distributed power generate technologies, and been used in spaceflight, comunication base station,automobile and consumptive electronics. To develop a fuel cell power generation, we designed a 1KW grid connected fuel cell inverter. This paper mainly focuses on the following aspects:a) To meet the special requiments of fuel cell, this paper introduces a DC/DC converter named Boost push-pull converter which is suitable for fuel cell, and its topology, control principle and realization are discussed in detail.b) Use unipolar harmonic modulation in the generation of full bridge drive signals, and realized it with a digital-analog conbined method. This helps to double the equivalent switch frequency, lower the switch cost, and achieve a better efficient in the end.c) Introduce a software-based islanding detect method with passive detect and active phase-shift detect. This method can detect the islanding in time and reduce the THD caused by the phase shift as well, which is proved simple and useful.d) Finish an inverter prototype and experiment shows the inverter's excellent electrical character and an idea solution for low voltage high current input circumstance.This grid connected fuel cell inverter has been successfully applied into a 1KW PEMFC power system and runs safely and stably. Experiment shows the inverter's excellent electrical character and an idea solution for low voltage high current input use.