Control of a hybrid wind-diesel microgrid

Abstract

This thesis presents the analysis and laboratory testing of a hybrid wind-diesel microgrid for islanded operation. The main focus of this research is to address energy deprived communities and, at the same time, reduce the Carbon Dioxide (CO2) emissions. The thesis specifically addresses power sharing control and synchronisation of the microgrid for highly-dynamic applications that require reliable and proven technology. The results presented in this thesis show the application of analytical tools and simulation in MATLAB/Simulink to study the behaviour of a hybrid wind-diesel power system, bringing a novel contribution in the application of these systems for security of supply for variable wind and load conditions. Analysis of a Doubly-Fed Induction Generator (DFIG) based wind turbine under different wind conditions and load levels is developed in this work, along with its connection to other alternating current power sources such as a diesel engine generator. A stability analysis of the DFIG is also presented to study the effects of different disturbances in the generator. The emulation of prime movers for laboratory use is also studied and implemented, contributing to the verification and validation process of the behaviour of a microgrid comprised of multiple generation sources. The proposed algorithm connects the diesel engine if the wind turbine power is above 60% and the wind speed is below 7m/s, to provide a margin of safety operation if the wind speed drops or the load increases. The diesel engine is disconnected at wind speeds above 7m/s, provided the wind turbine load is above 40%. Ideally, the diesel engine would only be used above 30% of its nominal power, to avoid effects such as sooting, but this limit is over-ridden, at high loads and low wind speeds, where the wind turbine cannot provide enough power alone. This control scheme is implemented in simulation and validated in a laboratory platform.

Date of Award	1 Aug 2021
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Judith Apsley (Supervisor) & Matteo Iacchetti (Supervisor)