Abstract

This paper presents a reduced order model of a microgrid system for a university community in Nigeria. The designed microgrid system is simulated in MATLAB/Simulink environment to determine the system dynamics. The obtained dynamic system is then reduced to a single block subsystem with multiple inputs and a single output using system linearization. The microgrid model is then linearized with the aid of linearization tool in MATLAB/Simulink using linearized perturbation method. The transfer function of the multiple inputs with respect to the single output of the microgrid system is determined in MATLAB environment. The transfer functions obtained for both inputs are then incorporated to the subsystem to linearize the entire system. The obtained linearized system is reduced with the aid of model reducer using the balanced truncation method in Simulink. The achieved results indicate that the system response of the obtained linearized model is linear compared to the step response of the nonlinear microgrid model of the campus. The results also reveal that the obtained reduced order model - compared to the nonlinear microgrid model - has lesser states with more than 4 times faster simulation response time.

Key words: Microgrid; MATLAB/Simulink; Model reducer; Perturbation method; System linearization; Transfer function.