A Differential Evolution Tuned Nonlinear Backstepping Controller for Three-Phase Grid-Connected Photovoltaic System

This paper presents an alternative technique to improve the gain tuning of nonlinear backstepping controller applied to three-phase grid-connected photovoltaic (PV) system in order to control active and reactive power fed into the grid. Gain parameters of nonlinear backstepping controllers play a key role in the convergence of currents corresponding to active and reactive power in grid-connected PV systems. The use of Differential Evolution (DE) optimization technique is proposed in this work, to obtain the optimised gain parameters while ensuring the fast convergence of errors associated with currents and this is done by minimizing the fitness function. Meanwhile, the gains are also optimised using an effective DE variant, differential evolution with composite trial vector generation strategies and control parameters (CoDE). The control parameter selection plays a vital role in the efficient performance of DE algorithm. However, the best choice of control parameters for optimum performance varies from problem to problem. Simulation studies are carried out to validate the effectiveness of the proposed scheme in terms of time responses (e.g., rise time, settling time, peak time, etc.)