scholarly journals L vs. LCL Filter for Photovoltaic Grid-Connected Inverter: A Reliability Study

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Ignacio Villanueva ◽  
Nimrod Vázquez ◽  
Joaquín Vaquero ◽  
Claudia Hernández ◽  
Héctor López ◽  
...  
Keyword(s):  
New Technologies ◽  
Harmonic Distortion ◽  
Photovoltaic System ◽  
Nonlinear Loads ◽  
Lcl Filter ◽  
Mean Time Between Failures ◽  
Time Between Failures ◽  
Power Injection ◽  
Grid Connected Inverter

The increasing use of photovoltaic systems entails the use of new technologies to improve the efficiency and power quality of the grid. System performance is constantly increasing, but its reliability decreases due to factors such as the uncontrolled operation, the quality of the design and quantity of components, and the use of nonlinear loads that may lead to distortion in the signal, which directly affects the life of the system globally. This article presents an analysis of the reliability of a single-phase full-bridge inverter for active power injection into the grid, which considers the inverter stage with its coupling stage. A comparison between an L filter and an LCL filter, which comprise the coupling stage, is made. Reliability prediction is based on metrics, failure rate, mean time between failures, and total harmonic distortion. The analysis and numerical simulation are performed. Finally, filter considerations are suggested to extend the reliability of the inverter in a photovoltaic system.

scholarly journals Impact of Harmonics on Power Quality and Losses in Power Distribution Systems

2015 ◽  
Vol 5 (1) ◽  
pp. 166 ◽  
Author(s):  
M. Jawad Ghorbani ◽  
Hossein Mokhtari
Keyword(s):  
Power Quality ◽  
Power Distribution ◽  
Distribution Systems ◽  
Harmonic Distortion ◽  
Equivalent Model ◽  
Power Distribution Systems ◽  
Nonlinear Loads ◽  
Distribution Feeder ◽  
The Impact

This paper investigates the harmonic distortion and losses in power distribution systems due to the dramatic increase of nonlinear loads. This paper tries to determine the amount of the harmonics generated by nonlinear loads in residential, commercial and office loads in distribution feeders and estimates the energy losses due to these harmonics. Norton equivalent modeling technique has been used to model the nonlinear loads. The presented harmonic Norton equivalent models of the end user appliances are accurately obtained based on the experimental data taken from the laboratory measurements. A 20 kV/400V distribution feeder is simulated to analyze the impact of nonlinear loads on feeder harmonic distortion level and losses. The model follows a “bottom-up” approach, starting from end users appliances Norton equivalent model and then modeling residential, commercial and office loads. Two new indices are introduced by the authors to quantize the effect of each nonlinear appliance on the power quality of a distribution feeder and loads are ranked based on these new defined indices. The simulation results show that harmonic distortion in distribution systems can increase power losses up to 20%.

scholarly journals Effects of Solar Irradiance on Load Sharing of Integrated Photovoltaic System with IEEE Standard Bus Network

2019 ◽  
Vol 9 (1) ◽  
pp. 424-429
Keyword(s):  
Power System ◽  
Harmonic Distortion ◽  
Photovoltaic Cell ◽  
Photovoltaic System ◽  
Photovoltaic Module ◽  
Controlled Environment ◽  
Photovoltaic Panel ◽  
Ieee Standard ◽  
Integrated Power System

This paper attempts to highlight the effect of change in load and irradiance on Photovoltaic integrated Power system network. The Power system network considered here is IEEE 14 bus system. The simulation is done on MATLAB platform and variation of Voltage, Power and Total Harmonic Distortion (THD) has been studied. The results indicates that how power quality of the power system is affected by the irradiance on Photovoltaic cell. The study is performed considering the other environmental factors such as wind velocity, ambient temperature and humidity have a negligible effect on the photovoltaic module. In a steady-state controlled environment, the simulation results show that the output voltage, current and its power decrease with time as the irradiance on the photovoltaic panel decreases.

scholarly journals ANFIS control of a shunt active filter based with a five-level NPC inverter to improve power quality

2021 ◽  
Vol 11 (3) ◽  
pp. 1886
Author(s):  
Mahmoud Mostefa Tounsi ◽  
Ahmed Allali ◽  
Houari Merabet Boulouiha ◽  
Mouloud Denaï
Keyword(s):  
Power Quality ◽  
Fuzzy Inference ◽  
Fuzzy Controller ◽  
Harmonic Distortion ◽  
Active Filter ◽  
Nonlinear Loads ◽  
Inference System ◽  
Shunt Active Filter ◽  
Neuro Fuzzy

This paper addresses the problem of power quality, and the degradation of the current waveform in the distribution network which results directly from the proliferation of the nonlinear loads. We propose to use a five-level neutral point clamped (NPC) inverter topology for the implementation of the shunt active filter (SAPF). The aim of the SAPF is to inject harmonic currents in phase opposition at the connection point. The identification of harmonics is based on the pq method. A neuro-fuzzy controller based on ANFIS (adaptive neuro fuzzy inference system) is designed for the SAPF. The simulation study is carried out using MATLAB/Simulink and the results show a significant improvement in the quality of energy and a reduction in total harmonic distortion (THD) in accordance with IEC standard, IEEE-519, IEC 61000, EN 50160.

scholarly journals A Control Strategy of a Single-phase H6-type Grid-connected Inverter with Low Harmonic Current

2018 ◽  
Vol 173 ◽  
pp. 02041
Author(s):  
Lin Chunxu ◽  
Zhou Chunhua ◽  
Li Wei ◽  
Chen Rui
Keyword(s):  
Control Strategy ◽  
Single Phase ◽  
Closed Loop ◽  
High Efficiency ◽  
Control Method ◽  
Harmonic Distortion ◽  
Outer Loop ◽  
Lcl Filter ◽  
Loop Control ◽  
Grid Connected Inverter

In order to reduce the total harmonic distortion (THD) of the grid-connected current caused by the high-frequency switching of the inverter, this paper combines the high efficiency single-phase H6-type inverter with LCL filter. The double closed-loop control method that consists of grid-connected current outer loop and capacitor current inner loop is put forward, by which a resonance peak of a low damping LCL filter is eliminated. In the grid-connected current outer loop, quasi proportion resonant (QPR) controller is adopted to overcome the steady-state error and weak anti-jamming capability in traditional PI controller. Finally, a simulation model is built in SIMULINK to verify the research. The simulation results show that, based on the single-phase H6-type inverter and LCL filter, the double closed-loop QPR control strategy can achieve the static error free tracking control of grid-connected current, which makes the system more stable and reduces the THD of grid-connected current effectively.

scholarly journals Impact of Harmonic Currents of Nonlinear Loads on Power Quality of a Low Voltage Network–Review and Case Study

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3665
Author(s):  
Łukasz Michalec ◽  
Michał Jasiński ◽  
Tomasz Sikorski ◽  
Zbigniew Leonowicz ◽  
Łukasz Jasiński ◽  
...  
Keyword(s):  
Power Quality ◽  
Low Voltage ◽  
Harmonic Distortion ◽  
Experimental Tests ◽  
Total Harmonic Distortion ◽  
Quality Analysis ◽  
Nonlinear Loads ◽  
Distortion Factor ◽  
Harmonic Currents

The paper presents a power-quality analysis in the utility low-voltage network focusing on harmonic currents’ pollution. Usually, to forecast the modern electrical and electronic devices’ contribution to increasing the current total harmonic distortion factor (THDI) and exceeding the regulation limit, analyses based on tests and models of individual devices are conducted. In this article, a composite approach was applied. The performance of harmonic currents produced by sets of devices commonly used in commercial and residential facilities’ nonlinear loads was investigated. The measurements were conducted with the class A PQ analyzer (FLUKE 435) and dedicated to the specialized PC software. The experimental tests show that the harmonic currents produced by multiple types of nonlinear loads tend to reduce the current total harmonic distortion factor (THDI). The changes of harmonic content caused by summation and/or cancellation effects in total current drawn from the grid by nonlinear loads should be a key factor in harmonic currents’ pollution study. Proper forecasting of the level of harmonic currents injected into the utility grid helps to maintain the quality of electricity at an appropriate level and reduce active power losses, which have a direct impact on the price of electricity generation.

PV Grid-Connected Inverter Islanding Detection Algorithm Improvements

2014 ◽  
Vol 721 ◽  
pp. 583-586 ◽  
Author(s):  
Chen Lu ◽  
Xiao Ming Sun ◽  
Yin Jin
Keyword(s):  
Harmonic Distortion ◽  
Detection Algorithm ◽  
Photovoltaic System ◽  
Islanding Detection ◽  
Current Harmonic ◽  
Advantages And Disadvantages ◽  
Grid Connected Inverter ◽  
Pv Grid ◽  
The Impact ◽  
The Relationship

In a photovoltaic system, function of islanding detection is an essential part of inverter. The system should not only fast detect islanding, but also minimize the impact on power grid. The relationship between the output current THD and the time of detection is discussed. This problem is analyzed in this paper and a new algorithm is proposed. Based on the improved AFDPF algorithm, this method effectively regulate the relationships between the truncated coefficient (cf), current harmonic distortion and island detection time and on the basis of the results of simulation, the results of improved AFDPF algorithm are analyzed. Finally, the advantages and disadvantages are summarized.

scholarly journals ANALYSIS OF INDICATORS AND COST OF WORLD CLASS MAINTENANCE (WCM) IN FOREST MACHINES

FLORESTA ◽  
2019 ◽  
Vol 49 (3) ◽  
pp. 533
Author(s):  
Carlos Cezar Cavassin Diniz ◽  
Eduardo Da Silva Lopes ◽  
Gabriel De Magalhães Miranda ◽  
Henrique Soares Koehler ◽  
Eduardo Kremer Custodio de Souza
Keyword(s):  
Maintenance Costs ◽  
Mean Time Between Failures ◽  
Time Between Failures ◽  
World Class ◽  
The Mean ◽  
Mean Time To Repair ◽  
Mean Time ◽  
Proactive Maintenance

The study was carried out at a forest company located in the Paraná State, Brazil, with the feller buncher, skidder and harvester. The following indicators were evaluated: mechanical availability, mean time between failures, mean time to repair, proactive maintenance index and maintenance costs, based on data obtained over a period of 18 months, contemplating the stages of implantation, maturation and stabilization of the WCM. The results showed an increase in the mechanical availability of the cutting and skidding machines from the implantation stage. The mean time between failures increased from the implantation stage, from 31.59 hours to 37.01 hours in the stabilization stage. As for the mean time to repairs, skidder and harvester presented an increase of 25.9% and 18.9% respectively; however, this increase in time represented an improvement in the quality of maintenance services, reflected in the results of mean time between failures. There was also a 31% increase in the proactive index of the machines studied, resulting in 9% reduction in maintenance costs between the deployment and stabilization stages.

scholarly journals PV-STATCOM in Photovoltaic Systems under Variable Solar Radiation and Variable Unbalanced Nonlinear Loads

2021 ◽  
pp. 36-48
Author(s):  
Youssef Ait El Kadi ◽  
◽  
Fatima Zahra Baghli ◽  
Yassine Lakhal
Keyword(s):  
Harmonic Distortion ◽  
Current Control ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Passive Components ◽  
Load Variations ◽  
Instantaneous Power ◽  
Zero Sequence ◽  
Static Compensator

The paper focuses on an efficient method to compensate the harmonics and zero-sequence component caused by the variable unbalanced nonlinear loads. The studied compensator is based on the conventional Static Compensator (STATCOM) which is supplied by a photovoltaic generator rather than the storage passive components. That constitutes a Photovoltaic Static Compensator (PV-STATCOM). In addition to the active power production, this PV-STATCOM will improve the quality of the electric grid highly disturbed without any additional devices and costs. The used control strategy is based on the instantaneous power method and current control. The obtained results show the benefits of the photovoltaic active filter compensator to improve the energy quality. Specially, the Total Harmonic Distortion (THD) is decreased from 28.80 % to 2.03 %. The zero-sequence component of the load currents is reduced from 31.50 % to 4.26 %. The results prove also a high stabilization and limitation of the harmful repercussions of the compensator on the photovoltaic station and an automatic adapting to the solar variable radiation and to the unbalanced nonlinear load variations.

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