This paper proposes the application of an adjustable speed diesel engine-driven power plant employing a Alarm Interface doubly-fed induction generator to an isolated small-scale power system including renewable power sources.This type of power plant can contribute to fast and flexible power balancing regulation under vacillating power supply such as wind, solar Left Moving Arm and other renewable power sources.Installation of a battery system is also considered, which can assist in coordinating the power plant to augment renewable power sources in the isolated power system.