Multi-string single-stage grid-connected inverter for PV system

During the day, photovoltaic (PV) systems are exposed to different sunlight conditions in addition to partial shading (PS). Accordingly, maximum power point tracking (MPPT) techniques have become essential for PV systems to secure harvesting the maximum possible power from the PV modules. In this paper, optimized control is performed through the application of relatively newly developed optimization algorithms to PV systems under Partial Shading (PS) conditions. The initial value of the duty cycle of the boost converter is optimized for maximizing the amount of power extracted from the PV arrays. The emperor penguin optimizer (EPO) is proposed not only to optimize the initial setting of duty cycle but to tune the gains of controllers used for the boost converter and the grid-connected inverter of the PV system. In addition, the performance of the proposed system based on the EPO algorithm is compared with another newly developed optimization technique based on the cuttlefish algorithm (CFA). Moreover, particle swarm optimization (PSO) algorithm is used as a reference algorithm to compare results with both EPO and CFA. PSO is chosen since it is an old, well-tested, and effective algorithm. For the evaluation of performance of the proposed PV system using the proposed algorithms under different PS conditions, results are recorded and introduced.

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A Robust Control based on Fuzzy Logic Approach of a Single-Stage Grid-Connected PV System

Proceedings of the 4th International Conference on Big Data and Internet of Things ◽

10.1145/3372938.3373008 ◽

2019 ◽

Author(s):

Ilham Nassar-Eddine ◽

Abdellatif Obbadi ◽

Youssef Errami ◽

Smail Sahnoun ◽

Mohssin Aoutoul ◽

...

Keyword(s):

Fuzzy Logic ◽

Robust Control ◽

Single Stage ◽

Pv System ◽

Fuzzy Logic Approach ◽

Logic Approach

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Modeling and Design of the Vector Control for a Three-Phase Single-Stage Grid-Connected PV System with LVRT Capability according to the Spanish Grid Code

Energies ◽

10.3390/en12152899 ◽

2019 ◽

Vol 12 (15) ◽

pp. 2899 ◽

Cited By ~ 7

Author(s):

Alexis B. Rey-Boué ◽

N. F. Guerrero-Rodríguez ◽

Johannes Stöckl ◽

Thomas I. Strasser

Keyword(s):

Vector Control ◽

Reactive Power ◽

Low Voltage ◽

Single Stage ◽

Photovoltaic System ◽

Lookup Table ◽

Voltage Sags ◽

Pv System ◽

Low Voltage Ride Through ◽

Three Phase

This article deals with the vector control in dq axes of a three-phase grid-connected photovoltaic system with single-stage topology and low-voltage-ride-through capability. The photovoltaic generator is built using an array of several series-parallel Suntech PV modules and is modeled as a Lookup Table (two-dimensional; 2-D). The requirements adopted when grid voltage sags occur are based in both the IEC 61400-21 European normative and the allowed amount of reactive power to be delivered according to the Spanish grid code, which avoids the disconnection of the inverter under grid faults by a limitation in the magnitude of the three-phase output inverter currents. For this, the calculation of the positive- and negative-sequences of the grid voltages is made and a conventional three-phase Phase-Locked Loop is used for the inverter-grid synchronization, allowing the control of the active and reactive powers solely with the dq components of the inverter currents. A detailed enhanced flowchart of the control algorithm with low-voltage-ride-through capability is presented and several simulations and experiments using Matlab/SIMULINK and the Controller Hardware-in-the-Loop simulation technique, respectively, are run for several types of one- and three-phase voltage sags in order to validate its behavior.

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