Solar Photovoltaic Fed Three-Phase Multifunctional Converter Operation Using a Nonlinear Control Strategy

Abstract

A nonlinear control strategy for a solar photovoltaic (SPV) integrated three-phase multifunctional converter (3PMFC) is proposed in this study. The proposed control strategy encapsulates the Lyapunov function controller (LFC) for the voltage control loop and a model predictive controller (MPC) for the current tracking control loop. The SPV source is integrated into the 3PMFC’s dc-link via a dc-dc boost converter. Aside from injecting active power generated by the SPV into the utility system at the unity power factor, the control algorithm of a 3PMFC includes multifunctional features such as current harmonic compensation, reac-tive power support, and source current balance. The dc-dc boost converter and 3PMFC reference currents are calculated using an incremental conductance-based maximum power point tracking (MPPT) algorithm and a variable conductance factor (VCF) technique, respectively. Furthermore, the MPC algorithm is used to design the current tracking controllers for the dc-dc boost converter and 3PMFC. The effectiveness of the proposed control technique was evaluated using different solar irradiation, dc-loads, and ac-loads (linear balanced, linear unbalanced , and nonlinear loads). Finally, under a dynamic operation scenario, the performance of the proposed control technique is assessed and validated using MATLAB/Simulink and real-time simulator (OPAL-RT OP4510) results.