Journal of Thermal Science and Technology (May 2007)
Dynamic Characteristics of PEM-FC/Woody Biomass Engine Hybrid Micro Grid
Abstract
The combustion exhaust heat of woody biomass engine using Stirling cycle is high temperature. This exhaust heat is used for the city gas reforming reaction of a proton exchange membrane fuel cell (PEM-FC) system. The woody biomass engine generator has the characteristic that the greenhouse gas amount of emission with power generation is greatly reducible. In this paper, the micro grid system that introduces PEM-FC/woody biomass engine hybrid cogeneration (PWHC) is proposed. It depends on the dynamic characteristics of the grid for the power quality at the time of load fluctuation being added to the micro grid. Especially, the dynamic characteristics of the independent micro grid are important on security of power quality. So, in this paper, the response characteristic of PEM-FC and woody biomass engine was investigated by the experiment and the numerical analysis. Furthermore, the response characteristic of the PWHC independent micro grid including auxiliary machinery was investigated by the numerical simulation. Moreover, an improvement of dynamic characteristics is proposed using the method of adding proportional-plus-integral control to PWHC. If woody biomass engine is introduced into a house, 10.2s will be required to stabilize power quality at the maximum. On the other hand, when woody biomass engine corresponds to a base load and PEM-FC corresponds to the load exceeding the base load, settling time is less than 1.6 s. In this study, relation between the system configuration of the PWHC micro grid and the dynamic characteristics of the power was clarified.
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