燃料电池功率调节系统的研究

燃料电池电压输出范围比较宽，电压比较低。针对该特点本文设计了DC/DC和DC/AC两级变换的功率调节系统(PCS)。其中DC/DC将燃料电池输出的低压直流电高频变换成高压直流电，变换器为电压单环控制。DC／AC逆变器采用基于电压电流瞬时值反馈的双闭环控制，将高压直流电逆变为正弦交流电。分析了整个功率调节系统的工作原理及逆变器电路参数对稳定性的影响。0．5KVA佯饥实验结果表明整个系统具有电压输入范围宽、变换效率高、输出波形THD小等优点。为开发高效、高功率密度的燃料电池电源系统提供技术基础。

STUDY ON POWER CONDITIONING SYSTEM FOR FUEL CELL

The output voltage of the fuel cell is low and has awide range. According to these, a power condtioning system(PCS) which is composed of DC/DC converter and DC/AC inverter is designed for the fuel cell in this paper. The phase-shifted full-bridge DC/DC converter is controlled with a single voltage loop. With the DC/DC converter, the low voltage output of the fuel cell is converted to a stabilized high DC and the high DC is inverted to sinusoidal AC voltage by the double loop controlled DC/AC inverter with the instantaneous voltage and current feedback control. The operation principles of the power conditioning system were analyzed and the effects of the parameters on the stability of the inverter were also presented. Experimental results of the 0.5kW prototype showed that the PCS has had the advantages of wide voltage input, high power density and low total harmonic distortion (THD) in output waveform. The PCS proposed in this paper which will be useful for developments of fuel cells with high power density and high efficiency.