scholarly journals Enhancing performance of grid-connected photovoltaic systems based on three-phase five-level cascaded inverter

Author(s):  
Marwan E. Ahmad ◽  
Ali. H. Numan ◽  
Dhari Y. Mahmood

<span lang="EN-US">Multilevel inverters play an important role in power converters due to their good advantages. The cascaded H-bridge inverter is one of the most prominent and most suitable multilevel inverters in PV systems. Each H-bridge has a separate photovoltaic (PV) array as an independent direct current (DC) source. This paper introduces a three-phase cascaded H-bridge inverter with five levels connected to the grid to improve the performance and efficiency of the photovoltaic system. In the proposed system, each PV group has MPPT to extract the maximum power point from the PV group at certain irradiation and temperature and also to mitigate the mismatch that causes in the imbalance transmitted power from inverter to the main grid. The proposed control scheme with modulation compensation was used, and the system was simulated in MATLAB/Simulink with two different scenarios. The simulation results demonstrate the effectiveness of the proposed connection in minimizing the total harmonic distortion (THD) to acceptable limit, low overshoot, and fast-tracking to the desired value.</span>

Author(s):  
Boucetta Abd Allah ◽  
Labed Djamel

Renewable energy is high on international agendas. Currently, grid-connected photovoltaic systems are a popular technology to convert solar energy into electricity. Control of power injected into the grid, maximum power point, high efficiency, and low total harmonic distortion of the currents injected into the grid are the requirements for inverter connection into the grid. Consequently, the performance of the inverters connected to the grid depends largely on the control strategy applied. In this paper the simulation and design of grid connected three phase photovoltaic system using Matlab/Simulink has examined. The proposed system consists photovoltaic panels, boost and inverter the PV system convert the sun irradiation into direct current, thereafter we have used a boost to track the maximum power point of the PV system, three-phase inverter and LC output filter. A VOC control strategy based on the phase shifting of the inverter output voltage with respect to the grid voltage. The proposed control strategy requires few hardware and computational resources. As a result, the inverter implementation is simple, and it becomes an attractive solution for low power grid connected applications.


Author(s):  
Boucetta Abdou Abdallah ◽  
Labed Djamel

Renewable energy is high on international agendas. Currently, grid-connected photovoltaic systems are a popular technology to convert solar energy into electricity. Control of power injected into the grid, maximum power point, high efficiency, and low total harmonic distortion of the currents injected into the grid are the requirements for inverter connection into the grid. Consequently, the performance of the inverters connected to the grid depends largely on the control strategy applied. In this paper the simulation and design of grid connected three phase photovoltaic system using Matlab/Simulink has examined. The proposed system consists photovoltaic panels, boost and inverter the PV system convert the sun irradiation into direct current, thereafter we have used a boost to track the maximum power point of the PV system, three-phase inverter and LC output filter. A VOC control strategy based on the phase shifting of the inverter output voltage with respect to the grid voltage. The proposed control strategy requires few hardware and computational resources. As a result, the inverter implementation is simple, and it becomes an attractive solution for low power grid connected applications.


2017 ◽  
Vol 40 (13) ◽  
pp. 3709-3720 ◽  
Author(s):  
Reza Dadkhah Tehrani ◽  
Faridoon Shabaninia

One of the main renewable energy sources for the future is photovoltaic (PV) energy. Hence, working of the PV systems at maximum efficiency is taken into consideration in recent years. In this paper, for improving the performance of the global maximum power point tracking under partial shading conditions and uncertainty in parameters of DC-DC converter, a two-level adaptive control scheme is proposed. The proposed controller is capable of efficiently handling the uncertainties in the PV systems and the perturbations in the environment. The first level is global perturbation-based extremum seeking control (GPESC), and the second level is model reference adaptive control (MRAC). GPESC is used to find global maximum power point and MRAC is utilized to handle the dynamics of the DC-DC converter. Adequate difference in the time constants of control levels, causes decoupled control levels, which in turn makes it easy to design the controller. The performance of the proposed control scheme is evaluated through simulation based on four indicators: tracking accuracy, tracking efficiency, tracking speed and searching resolution for different irradiance patterns. The results are compared with GPESC and GPESC with PID controller.


2012 ◽  
Vol 608-609 ◽  
pp. 164-168
Author(s):  
Jian Jun Su ◽  
Men Yue Hu ◽  
Hong Yan Gong ◽  
Hai Tao Sun ◽  
Zhi Jian Hu ◽  
...  

Firstly the research situation for grid-connected photovoltaic (PV) is introduced, then, the engineering mathematical model of PV cells is introduced. The perturbation and observation algorithm is chosen as the maximum power point tracking (MPPT) algorithm. The SPWM double-loop control strategy with outer voltage loop and inner current loop is described and a three-phase grid-connected photovoltaic model is established. The simulation results demonstrate the validity and correctness of the simulation model built in this paper.


2019 ◽  
Vol 9 (2) ◽  
pp. 29-35
Author(s):  
Rachid Belaidi ◽  
Boualem Bendib ◽  
Djamila Ghribi ◽  
Belkacem Bouzidi ◽  
Mohamed Mghezzi Larafi

The main goal of maximum power point (MPP) tracking control is to extract the maximum photovoltaic (PV) power by finding the optimal operating point under varying atmospheric conditions to improve the efficiency of PV systems. In recent years, the field of tracking the MPP of PV systems has attracted the interest of many researchers from the industry and academia. This research paper presents a comparative study between the modern fuzzy logic based controller and the conventional perturb & observe (P&O) technique. The comparative study was carried out under different weather conditions in order to analyse and evaluate the performance of the PV system. The overall system simulation has been performed using Matlab/Simulink software environment. The simulation results show that the dynamic behaviour exhibited by the modern fuzzy controller outperforms that of the conventional controller (P&O) in terms of response time and damping characteristics.   Keywords: MPPT, photovoltaic system, fuzzy logic control, P&O algorithm.


2021 ◽  
Vol 16 (2) ◽  
pp. 213-221
Author(s):  
Na Yao ◽  
Zhi Zhang ◽  
Xiao Tang

The photovoltaic cells’ output characteristics and maximum power point tracking (MPPT) technology are studied to design a two-stage cascaded photovoltaic off-grid inverter, including the front-end Boost converter and the rear-end three-phase inverter. The state-space averaging method is adopted in front-end Boost converter modeling, and space vector pulse width modulation (SVPWM) technology is adopted in the rear-end three-phase inverter. The simulation drive model is obtained through research principles and algorithm realization. Based on the theoretical analysis and simulation, front-end Boost converter’s and the back-end inverter’s hardware are designed. The main circuit includes the front-end Direct Current (DC)-DC topology and the back-end DC-AC topology. The TMS320F28027 digital signal processor is the core of the front-end DC-DC topology’s control system, and LabView is the core of the back-end DC-AC topology’s control system. The front-end Boost converter’s analog output voltage is 32 V, stable at the maximum operating point in the test. The maximum power point can be effectively tracked in the proposed inverter. The rear-end three-phase inverter’s total harmonic distortion (THD) of phase voltage is less than 3%. Less harmonic wave meets the circuit harmonic distortion rate’s design requirements.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Muhammad Bilal Satti ◽  
Ammar Hasan ◽  
Mian Ilyas Ahmad

The demand for clean and sustainable energy has spurred research in all forms of renewable energy sources, including solar energy from photovoltaic systems. Grid-connected photovoltaic systems (GCPS) provide an effective solution to integrate solar energy into the existing grid. A key component of the GCPS is the inverter. The inverter can have a significant impact on the overall performance of the GCPS, including maximum power point (MPP) tracking, total harmonic distortion (THD), and efficiency. Multilevel inverters are one of the most promising classes of converters that offer a low THD. In this paper, we propose a new multilevel inverter topology with the motivation to improve all the three aforementioned aspects of performance. The proposed topology is controlled through direct model predictive control (DMPC), which is state of the art in control techniques. We compare the performance of the proposed topology with the topologies reported in literature. The proposed topology offers one of the best efficiency, MPP tracking, and voltage THD.


Maximum power point tracking is a method employed to produce the utmost power available from the photovoltaic module. To date, many algorithms for maximum power point tracking technique had been stated, every with its own capabilities. In this paper, a Luo converter with high-voltage conversion gain is employed to track photovoltaic panels at maximum power and to step up the voltage to a higher level. This work also aims to validate the performance of the maximum power point tracking system with Luo converter which utilizes incremental conductance techniques. Space vector modulation and sinusoidal pulse width modulations are the control techniques employed to control the three-phase voltage source converter. In order to measure the overall performance indices of the proposed system, a simulation is carried out in MATLAB / Simulink environment.


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