Development of a diesel generating set model for large voltage and frequency transients

This paper presents a model which can be used to simulate the load acceptance behavior of a diesel generating set. Unlike traditional thermal plants, generating sets (gen-sets) are often expected to undergo large rapid changes in load. A gen-set with a low inertia will naturally be more susceptible to changes in speed. This problem is compounded with the introduction of turbocharged engines. Although turbochargers increase a gen-set´s rating they can be detrimental to transient performance. The gen-set model in this paper contains sub-models for the diesel engine, synchronous machine, fuel governor and automatic voltage regulator. The model has been developed with the intention to simulate a backup supply scenario where the gen-set would initially be unloaded and have an electrical load applied in a single step. The model simulates the resulting large voltage and frequency transients.