Optimal Control System of Under Frequency Load Shedding in Microgrid System with Renewable Energy Resources

Abstract

Nowadays many of the power systems are facing serious problems because of the lack of know-how to utilize the available renewable energy resources (RER) so as to balance between the power supply and demand sides. As the consequence of the power unbalancing into their distribution networks, under frequency load shedding (UFLS) which leads to life span reduction of various expensive equipment and deteriorating production in general are of much concerns. Thus, proper control system for the load flow in a system like microgrids (MG) with RER in general is the first thing to carry out the assessment with the aim to solve the power balancing problem within the power system networks. Actually, the major problems which many utilities are facing all over the world are how to utilize the available and future energy resource reserves in order to balance between the supply and demand sides within their power distribution networks. Moreover, because of the quick, improvised and unforeseen increasing number of consumers’ power demands and lack of additional macro energy resources plants which can favorably respond to the instantaneous consumer requirements, optimal control strategy (OCS) is inevitable. The OCS is required to maintain the steady-state operations and ensure the reliability of the entire distribution system over a long period. For that case, the OCS is required to principally stabilize parameters such as voltage, frequency, and limit the injection of reactive power into the MG system under stress. Therefore, in this chapter, the OCS is proposed as an approach to be applied in an intelligent way to solve the UFLS and blackout problems (BP) in a typical MG with RER. The proposed control solution is analyzed using emergency power supply reserves integrated with RER. These typical energy resources can be wind and photovoltaic (solar PV) systems associated with the battery energy storage system (BESS), hydro pump storage, biomass power plant and fuel cell systems.