Adaptive backstepping controller based on energy concept of shunt active power filter connected to PV system

This paper suggests an innovative approach for controlling single-phase shunt active power filter powered by photovoltaic arrays (PV-SAPF) amidst nonlinear loads. The proposed controller design is built upon the theoretical energy stored within the half-bridge SAPF components and aims to achieve two objectives simultaneously: (i) maximize active power generation from solar panels and regulate the PV voltage at a predefined reference value using the Incremental Conductance MPPT algorithm. (ii) compensate harmonic currents and reactive power produced by nonlinear loads using the backstepping approach and Lyapunov tools. This advanced control system is designed in two loops. An inner loop comprising a Power Factor Correction (PFC) regulator based on the theoretical energy stored in the SAPF components to reduce the Total Harmonic Distortion (THD) and to guarantee a near-unit power factor. An outer loop using a Proportional-Integrator (PI) regulator to control the PV voltage. Additionally, this system includes an adaptive observer on the AC side to estimate the unmeasurable state network variables by analyzing the estimated network current. The performances of the proposed controller are rigorously assessed using stability analysis tools, and validated through various extensive numerical simulation conducted in MATLAB/SIMULINK software. Furthermore, the effectiveness and robustness of this controller are compared to another controller developed in the study, which relies exclusively on the conventional PI filter.