FCS‐MPC for a single‐phase two‐stage grid‐connected PV inverter

The high-efficiency inverter in a wide input voltage range is expected to be a solution for the distributed generation system. This study gives a high-efficiency two-stage topology and proposes a finite-control-set model predictive control (FCS-MPC) strategy. The main objectives of the proposed model predictive controller are: (i) simultaneously controlling multi-variables in the complex buck-boost current controller, (ii) optimal design calculation for predictive current and voltage, (iii) normalisation of the state variables for cost function formulation, and (iv) low correlation between the dc-link capacitor and control algorithm. A more reasonable operation mode of high-frequency switches is provided for the two-stage topology improving system performance. In order to optimise the total harmonic distortion of the output current and the error of the dc-link voltage, a suitable weighting factor could be designed in the proposed FCS-MPC method. The steady-state characteristics of the proposed controller are simulated based on MATLAB/Simulink. Experimental results demonstrate the validity and practicability of the proposed control strategy.