A high-efficiency, high-quality power supply implemented with a lean-burn gas engine and a power storage device

In recent years, various types of gas-fueled combined heat and power (CHP) systems have been developed and introduced into sites such as hospitals, hotels, commercial buildings, district heating & cooling centers, factories, etc., to increase energy savings and reduce greenhouse gases. Typical components integrated into CHP systems are gas engines (GE), gas turbines (GT), and fuel cells (FC); the recent trend of development for such components is a high-efficiency large-scale model or a distributed small-scale model. In addition to obtaining a highly efficient power production system by interconnected operation, emergency power could be supplied by an islanding operation that is the most distinctive ability of distributed generators to keep social infrastructure from disaster. However, high-efficiency gas engine CHPs are not suitable for islanding operations because of instability during load changes. In this study, we describe a highly efficient gas engine CHP combined with power storage devices, which will establish stability during islanding operations, and provide an uninterrupted emergency power supply for critical loads. We demonstrate the design of cooperative control between two power sources to derive better performance from the integration.