Design and Implementation of Predictive Current Controller for Photovoltaic Grid-Tie Inverter

This paper presents simplified predictive current controller for 3-ph PWM voltage source inverter connected to the utility grid via filter inductance. By controlling inductance voltage drop, the inverter voltage and hence the injected current can be controlled. The proposed predictive control technique operates with constant switching frequency using space-vector modulation (SVM). In each switching period, the proposed control algorithm computes the required inverter average voltage vector in α–β reference frame in order to follow up the reference current at the end of the switching period. The proposed technique has no need for coordinate transformations or PI controllers. The proposed controller is verified by simulation using MATLAB/Simulink, and is experimentally verified using a fixed point microcontroller (Maple microcontroller). Detailed implementation of the proposed hardware is presented. Both simulations and experimental results are presented in the paper. Key-Words: Predictive Current Control, SVM, Grid-Tie, Distributed Power Generation Systems.