Improving the Small Signal Stability of a PV-DE-Dynamic Load-Based Microgrid Using an Auxiliary Signal in the PV Control Loop

摘要

In this paper, a small signal model has been developed for a grid connected photovoltaic (PV)-diesel engine (DE) system feeding also to an induction motor at the low voltage level. The comprehensive mathematical model of the system has been developed by linearizing the system of equations around an operating point. To analyze the stability of the system, the eigen values and thus the modes of the system have been obtained from the resultant analytical A matrix. Further, to validate this small signal model, a complete nonlinear time-domain analysis of the system has been carried out. In order to enhance the stability of the system, a supplementary controller in the PV control loop has been proposed and its results have been verified both from the eigen values and from the nonlinear analysis.