Appendix.

This study is concerned with the power quality issues in the distribution network. One of the major problems facing power electronics technology nowadays is protecting the power distribution system from the harmful effects of current harmonics generated by nonlinear loads connected to the grid. On the other hand, the use of renewable energies is more than necessary; it is a global strategic issue and it would be a tool against global warming.
This research proposes a high-performance control scheme for a double function grid-tied double stage PV system. It is based on predictive direct power control with space vector modulation (P-DPC-SVM). This strategy uses a discrete model of the system based on time domain to generate the average voltage vector, at each sampling period, with the aim of canceling the errors between the estimated active and reactive power values and their references. Also, it imposes the sinusoidal waveform of the current at the grid side, which allows active power filtering without harmonic currents identification phase. The latter attempts to reduce the size and the cost of the system as well as providing better performance. In addition, it can be implemented in a low-cost control platform due to its simplicity. The performance of P-DPC-SVM is compared with Direct power control and Finite-control-set Model predictive control.
A double stage PV system is selected due to its flexibility in control, unlike the single-stage strategy. Sliding mode control based particle swarm optimization (PSO) is used to track the maximum power of the PV system. It offers high accuracy and good robustness. Concerning the DC bus voltage of the inverter, the anti-windup PI controller is tuned offline using a particle swarm optimization algorithm to deliver optimal performance in DC bus voltage regulation. All the studied control approaches are investigated in simulation using Matlab/Simulink and validated in an experimental test bench based on dSPACE 1104.