Backstepping fractional terminal sliding mode voltage control of an islanded microgrid

Abstract

Distribution networks include thousands of sensors and a large number of controllable devices such as flexible loads, batteries and distributed generators with an arbitrary configuration that can be parametrically uncertain or topologically unknown. In this paper a new nonlinear voltage control strategy based on backstepping and fractional order sliding mode control is presented for an islanded microgrid. Primary objective in this paper is to improve robust performance and disturbance rejection of the closed loop control system hence a backstepping fractional order terminal sliding mode control (FBTSMC) is proposed here. The proposed controller robustly regulates the microgrid voltages in the presence of parametric uncertainties, unmodeled dynamics, imbalanced loads and nonlinear loads with harmonic. Finally, the performance of the proposed technique is investigated under disturbance in an islanded micro grid. An in-depth comparative study is done to highlight the merits of the proposed controller. Simulation results revealed that the Total Harmonic Distortion (THD) and the steady-state error of output voltage are successfully decreased and the dynamic performances and the capability of perturbation rejection are efficiently improved.