Finite Set-Model Predictive Control Method for Triple-Boost Doubly Grounded Three-Phase Photovoltaic Inverter

Step-up multilevel inverter (MI) topologies have fund vast applications in renewable energy systems. Recently, single stage transformerless MIs are preferred solutions in photovoltaic (PV) systems over two stage power conversion structures for efficiency, cost, and reliability point-of-views. The triple boost MI represents effective solution for PV applications with its inherent doubly-grounded feature. In which, the leakage current components are totally eliminated. However, the proper operation of this topology requires efficient control of the output grid currents and capacitor voltages. This paper presents a finite control set model predictive control (FCS-MPC) method for three phase doubly grounded triple boost PV topology. The operation, mathematical model and controller design are presented in this paper. The simulation results verify the effectiveness of the proposed method to generate high quality output currents and reduced voltage ripples over capacitors at various operating conditions.