Model Predictive Direct Power Control Applied to Grid-Connected Voltage Source Inverters

Abstract

This paper presents a model predictive control (MPC) implemented to a voltage source inverter (VSI) using a direct power model (DPM) representation. The VSI is connected to the ac grid through an RL-filter. The DPM representation allows controlling instantaneous active and reactive power, regardless of the VSI without using a phase-locked loop. The MPC-DPC performance is assessed, making changes of the active and reactive power and considering unbalance voltage in the ac grid. In addition, it is also compared to a feedback linearization with an integral action (FBL) using DPC representation. The active and reactive power tracking errors and the spectrum currents are used to quantify and validate the advantages of proposed controller. Time-domain simulations have been carried out in Matlab/simulink and the MPC is computed using MOSEK solver interfaced with YALMIP toolbox in Matlab. The active and reactive power tracking errors and the spectrum currents are used to quantify and validate the advantages of proposed controller. Results show that the proposed controller presents a better performance than the FBL-DPC approach.