Isolated Microgrid Frequency Control Using Decentralized H∞ Loop Shaping

Isolated microgrids have become an important topic in research; they can provide energy to remote areas using the available local energy resources including the renewable ones. However, there are some technical problems that face their increasing use such as the frequency deviations specially if renewable sources are used in the microgrid. This work presents a control scheme to minimize the fluctuation in frequency of an isolated microgrid comprising Renewable Energy Sources (RES). The presence of the fluctuating RES in the microgrid leads to deviations in the frequency which in turn can affect stability not to mention performance. Decentralized Robust H infinity (H∞) loop shaping controllers are proposed to keep the deviation in frequency to a minimum in the presence of high levels of uncertainties and provide good disturbance rejection. Particle Swarm optimization is used for H∞ loop shaping controllers and the results are compared against those of PID controllers and shows the effectiveness of the proposed control in terms of robustness, stability and performance.