An improved synchronous reference frame current control strategy for a photovoltaic grid-connected inverter under unbalanced and nonlinear load conditions.

Amirreza Naderipour,Mohammad Reza Miveh,Mohd Hafiz Bin Habibuddin,Abdullah Asuhaimi Mohd Zin,Josep M Guerrero,Houbing Song

doi:10.1371/journal.pone.0164856

Amirreza Naderipour, Mohammad Reza Miveh + Show 4 more

Open Access

https://doi.org/10.1371/journal.pone.0164856

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Journal: PloS one	Publication Date: Feb 13, 2017
Citations: 23	License type: CC BY 4.0

Affiliation: University of Technology Malaysia, Aalborg University

Abstract

In recent years, renewable energy sources have been considered the most encouraging resources for grid and off-grid power generation. This paper presents an improved current control strategy for a three-phase photovoltaic grid-connected inverter (GCI) under unbalanced and nonlinear load conditions. It is challenging to suppress the harmonic content in the output current below a pre-set value in the GCI. It is also difficult to compensate for unbalanced loads even when the grid is under disruption due to total harmonic distortion (THD) and unbalanced loads. The primary advantage and objective of this method is to effectively compensate for the harmonic current content of the grid current and microgrid without the use of any compensation devices, such as active and passive filters. This method leads to a very low THD in both the GCI currents and the current exchanged with the grid. The control approach is designed to control the active and reactive power and harmonic current compensation, and it also corrects the system unbalance. The proposed control method features the synchronous reference frame (SRF) method. Simulation results are presented to demonstrate the effective performance of the proposed method.

Highlights

Among the various renewable energy sources (RESs), photovoltaics (PVs) are the most promising environmental friendly and fastest growing clean and renewable energy source [1,2]
The main limitation associated with MGs occurs when exchanging the current from the grid to the MG [6,7,8]; this exchange is considered a source of harmonic distortion in a grid-connected inverter (GCI) [9]
This study proposes a new control strategy for harmonic current compensation for distributed generators (DGs) interface converters in an MG

Summary

Introduction

Among the various renewable energy sources (RESs), photovoltaics (PVs) are the most promising environmental friendly and fastest growing clean and renewable energy source [1,2]. The methods in [17] and [9] were proposed to compensate for current harmonics in grid-connected MGs. The current controller proposed in [17] uses the synchronous reference frame (SRF) and is composed of a proportional–integral (PI) controller and a repetitive controller (RC). The proposed control strategy consists of an SRF method, which is proposed to control power injection to the grid, provide harmonic current compensation and correct the unbalanced system. The proposed method contains two units: the active and reactive power control unit and the harmonic current compensation unit. This block diagram is applicable for main and remaining harmonic compensation, reactive power supply for distortion sources and system unbalance correction.

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Findings

Conclusions