Comparative Analysis of PI and PR Controller for Grid-tied Solar Photovoltaic System

Abstract

This paper compares the proportional integral (PI) controller with the proportional resonant (PR) controller for a grid-catenated photovoltaic (PV) system. This control technique employs a dual loop, with the external loop controlling the DC-link voltage. The internal loop governs the infused inverter output current. Eminent infirmity of PI regulator is steady-state erratum whilst tracing a sine reference wave, and the d-q axis is interlinked in the synchronous reference frame (RF) for a PI current regulator and thus, dissociated components must be subsumed, which is not obligatory for the operation of PR controller in a stationary RF. The PR controller can overture a high gain at the power frequency, resulting in nought steady-state erratum whilst monitoring a sine reference wave. A harmonic compensator (HC) is being incorporated for the grid-concatenated solar PV system in addition to the PR controller. As a result, MATLAB analysis validates that the system infuses sine current into the electrical grid at a power factor of 1, and the total harmonic distortion (THD) of the AC-DC converter current for the PI current regulator is higher than the PR current regulator.