Transient performance analysis of low voltage connected microgeneration

The growing awareness of the environmental impacts of large-scale thermal generating units has stimulated interest in microgeneration that is installed within domestic or commercial premises. This paper investigates the transient response to be expected from a range of microgeneration units that could typically be connected. The paper examines the impact of fault locations, typical fault clearance times and generator/prime mover technologies on the ability of microgenerators to maintain stability when subject to disturbances during and after clearing of both local low and remote medium voltage faults. The paper also presents the study of the step voltage changes occurring due to the simultaneous reconnection of a large number of microgenerators within a small area of the network. Two types of technologies are considered in this paper: a small diesel engine driving a three-phase synchronous machine connected within commercial premises; and a small microwind turbine interfaced directly within a residential dwelling by a single-phase induction generator.