Synchronization Of Distributed Generators In A Microgrid Under Communication Latency

In this paper we study the voltage and frequency synchronization control of distributed generators (DG) in an islanded microgrid (MG) over a time-delayed communication network. When the microgrid is islanded from the utility grid, the transient voltage and frequency instability is further worsened by the presence of a large time delay in the network. As a means to achieve stability and satisfactory synchronization control for the group of DGs within the MG, this paper presents a consensus based distributed voltage and frequency control protocol, in which the effects of time delays associated with the exchange of information through the communication network is considered. By using the low gain methodology, sufficient delay dependent stability conditions and an upper bound for the low gain parameter were derived to ensure the stability of the synchronization in the face of communication delays. With the low gain parameter being selected from the derived bounds, we also show that the control protocol can always achieve this synchronization for any arbitrarily large delays. Finally, we validate the developed theoretical results in this paper with the help of a numerical example.