Frequency Stability Considerations of Reciprocating Gas Engine Generators in Microgrids

This paper considers the suitability of the standard DEGOV diesel generator governor model for use with reciprocating gas engine generators acting as primary frequency control units, within microgrids, due to the reduced capability of gas engines to accept step loads. The paper found that use of the standard DEGOV model would significantly overestimate the gas engines capability to accept step load, and an alternate model was developed using a gain scheduling controller, based on the generators existing loading. This model was found to be effective, but it was identified that the varying values of gain could lead to controller instability and tuning problems, and further investigation work in this area is necessary.