Modeling and simulation of an autonomous hybrid power system

Renewable energy sources contribute to overcome the problem of environmental pollution and secure the energy independency every country needs, while at the same time the autonomous microgrids can improve the electrification rates of poorer countries. In this article, the modeling process and operation of an autonomous hybrid power system are studied for a hypothetical case study of electrification of a remote village of 100 inhabitants in Kenya. The microgrid consists of photovoltaics, wind turbine, batteries, diesel genset, basic loads of different priorities, water pumping and purification load. The system is modeled in Simulink MATLAB and is simulated in terms of power management. The primary load is categorized in different priorities, while water pumping and purification is used as deferrable load. The “load following” dispatch strategy is adopted. The outputs of the model are the power produced by the various sources and the power consumed by all loads during the simulation time, as well as the produced and consumed energy, information on the battery operation and the dumped power or the power shortage. Both the microgrid's operation and the performance of the dispatch strategy are evaluated considering the level on which the citizens' energy needs are covered and the efficient management of the produced energy. Managing the extra power or tackling the deficit of power in the system are the key issues to be addressed. After all, the model represents reliably the behavior of the microgrid and several improving actions are suggested, based on the results analysis.