DQ-Based Radial Basis Function Controller for Single-Phase PEC9 Inverter

Controlling active and reactive powers in single-phase grid-connected inverters is matter of issue. This paper proposes an intelligent controller using Radial Basis Function (RBF) artificial neural network in a single-phase Direct Quadrant (DQ) frame to control active and reactive powers generated by nine-level Packed E-Cell (PEC9) inverter. Because of using single DC source, single DC link and less number of power switches, PEC9 is much interesting for grid-tied applications. In the proposed RBF-based control loop, active and reactive powers are separately controlled by using single-phase DQ transform. Since the grid current is converted to DC form, transient and steady-state errors can be suppressed remarkably. Simulation tests performed by MATLAB software show that the proposed DQRBF control loop desirably tracks active and reactive current references without significant transient response under different dynamic modes. The results also illustrate low THD, minimum capacitor voltage ripple and unity power factor.