Current control of three-phase grid-connected PV inverters using adaptive PR controller

In recent years, there has been a rapid increase in the number of grid connected three phase inverter systems being connected to the distribution network. As a result, the need for high quality, low harmonic distortion, current injection into the grid is essential. To achieve this, careful consideration of the inverter controller is necessary. Many control methods are based on the traditional proportional-integral controller (PI), or the more recently adopted Proportional Resonant controller (PR). This paper presents a new technique of minimizing the error of the current control in a three phase grid connected inverter using a readily implementable Adaptive Proportional Resonance controller. Simulation and experimental results demonstrate the effectiveness of the proposed technique.