Active power coefficient control for grid-tied photovoltaic system under voltage distortions

Abstract

ABSTRACT Grid-integrated solar photovoltaic (GSPV) system requires a simpler and computationally less intensive control algorithm for continuous maneuver of real power inoculation and power quality enhancement underneath diverse operating conditions. In order to reduce the computational burden, this article presents an active power coefficient (APC)-based control strategy for extracting the fundamental weight factor. The proposed structure utilizes only three mathematical operators for weight extraction, and thereby reduces the computational burden. Therefore, only 35 µs sampling time is required to implement the proposed control through low-cost ARM cortex M4-based microcontroller. As a result, the proposed control provides following advantages: 1) faster response 2) lesser current distortions, 3) lesser DC-link oscillations, and 4) lower implementation cost. Moreover, the improved linear time invariant-enhanced phase look loop (LTI-EPLL) structure is also proposed for synchronization of GSPV system. This structure accurately trails the phase angle and frequency of voltage signals despite the presence of DC component and harmonics. Besides, the amplitude estimation loop removes the dependency of supply magnitude from unit template. Further, the proposed APC algorithm and synchronizing control is designed in waijung environment of MATLAB/Simulink for testing various operating conditions. Finally, the total harmonic distortion of source current is remarkably decreased to 1.67%, which is well within the limits of IEEE 519 standard.