Enhancement of microgrid dynamic frequency stability using microgrid frequency controller (MGFC)

In this age of electricity where the energy demands are increasing, an important point should be taken into account that today's power system is not able to meet these needs as it is stressing the capabilities of transmission. A distributed generation system (DG) generates electricity from many small energy sources. It has the ability to supplement for the growing demands. In this situation, conventional distribution networks that accept distributed generation connections may face serious difficulty when its control and protection functions become more complicated. Microgrid infrastructure can solve the problems arising from large penetration of DGs if properly controlled. Load frequency control strategies should be implemented for a successful operation of a Microgrid in order to maintain proper power equilibrium in the system.;In this thesis, a novel MicroGrid Frequency Controller (MGFC) is introduced to address the frequency control of a microgrid. The proposed MGFC is a secondary level frequency controller which takes the weighted average of the frequency deviations at load buses as input. The output of MGFC is divided among the DGs (depending on the generation reserve, proximity to the inductive load) and fed as an additional input to the governor system. The main goal of the MGFC is to maintain zero steady state errors for frequency deviation and good tracking for load demands. The proposed MGFC was tested through the dynamic simulation of a microgrid test system in MATLAB in the presence and absence of MGFC for various disturbances. Simulation results show that, with inclusion of the proposed MGFC, system frequency is restored back to the normal value of 60 Hz with improved dynamic for the overall system.