A Model predictive current control Strategy for Grid-Connected single-stage Boost Inverter in solar Photovoltaic Systems.

The grid-connected single-stage boost inverter (GCSSBI) reflects as an attractive solution in interfacing of photovoltaic system having low dc voltage power source with ac loads or utility grid. While the classical control techniques for SSBI are based on pulse-width modulation (PWM) techniques, this paper explores the detailed description and performance analysis of model predictive current controller (MPCC) strategy for GCSSBI. In this approach, the future value of current is predicted for all the voltage vectors and selects the switching state vector which minimises the error between the output currents and their references. The selection of suitable cost function parameters containing continuous control sets mitigates the predicted horizon and also maintains the good quality of grid current. In this paper, the performance of the controller is analysed during its operation for change in input voltage, variation in solar irradiance level, and with various load conditions of solar PV (SPV) fed GCSSBI towards predictions of grid current with reduced total harmonics current distortion (THCD) as well as the synchronisation of boost inverter voltage with grid voltage. The MATLAB simulation results validate the effectiveness of the proposed MPCC controller for excellent reference tracking with low THCD for the above varying conditions. Finally, the controller increases the desired output current quality by mitigating the THCD of the output grid current less than 2% from the inverter and grid side.