The influence of diesel generators on frequency stability for isolated grids with high wind power penetration

The power generation of isolated power systems is based on expensive oil-fired or diesel conventional power plants. The combination of wind/diesel hybrid power systems is one of the most common proposed and promising solution for stability problems. This paper deals with the definition of an optimal combination for diesel generators from a technical point of view. On the one hand the extreme case that the power infeed equals the power demand without power reserves is considered and on the other hand a high amount of wind power is taken into consideration. The main goal is to find out if in case of dynamic events which are related to frequency stability, the power system would collapse for the operating conditions of minimum load and high wind power penetration. The scope is both to ensure system stability for different combinations of conventional generation, as well as to verify grid code requirements for providing active power support from Renewable Energy Sources that is required for the power system of the island of Lesbos in Greece.