Load Response Characteristics of a Fuel Cell Micro-grid with Control of the Number of Units

Abstract

The micro-grid is expected to reduce the discharge of carbon dioxide gas, to cut the peak of an electric power plant, and to supply backup power in an emergency [21–23]. A micro-grid technique connects energy equipment, such as an engine generator and a fuel cell, and power is supplied by each cooperating piece of equipment. In forming a micro-grid, the coordinated grid system with commercial power, etc., and the independent grid system should be considered. In the coordinated grid type, the supply and demand of power with a commercial system are possible, and the peak cut of an electric power plant and the buying and selling of power are possible. If the exhaust heat of the generating equipment linked to a micro-grid needs to be conveyed only a short distance, it can be supplied to the consumer with small radiation loss. On the other hand, in the exhaust heat of the large-scale conventional power plant, long distance transport has many heat losses, and utilization of exhaust heat is limited. One of the problems predicted by the construction of a micro-grid is that power quality deteriorates when the power demand and supply balance of the grid do not balance. The deterioration of the power quality described in this chapter means that fluctuation of voltage and frequency because the dynamic characteristics of an electric power supply do not meet the demand. Power quality can be maintained comparatively easily by controlling the voltage and frequency of a grid by a coordinated grid type to synchronize with another network, such as commercial power [51].