연료전지를 위한 독립형 3KW 인버터 시스템의 설계

Abstract

본 논문에서는 PEM Fuel Cell의 전압-전류 특징 및 동작원리에 대하여 살펴보았고, 기존의 고주파 DC/DC 컨버터를 분석하여 연료전지의 특성에 맞는 DC/DC 컨버터를 설계하였다. 기존의 연료전지용 DC/DC 컨버터의 문제점인 기동전류와 컨버터 입력전류의 고조파 성분을 감소할 수 있도록 설계하였으며 이를 시뮬레이션과 실험을 통하여 검증하였다.

This paper proposes a 3kW DC/DC converter and inverter system for stand-alone PEM fuel cell. Recently the various fuel cells are attracting a lot of concern as an energy source of the next generation. But the fuel cells have such characteristics as large variation of output voltage when the output current varies due to the load change. Furthermore, the magnitude of fuel cell output voltage is relatively low even if a lot of fuel cells are accumulated and stacked. Thus the fuel cells always need a DC/DC converter to boost the output voltage to a proper level of 400[v], for example, and an inverter to converter DC voltage source to AC voltage of 220[v]. In general the conventional DC/DC converters for the fuel cell utilize one of buck-type DC/DC converter and boost-type one as a main power converter. But the buck-type DC/DC converter and boost-type one have some disadvantages of starting problem and high ripple input current, respectively. To overcome the problems of the conventional power converters for fuel cell, this paper proposes a new DC/DC converter and inverter system for stand-alone fuel cell. The main characteristics of proposed converter are analyzed in detail and its effectiveness is proved by simulation results and experimental ones.