scholarly journals Power Quality Experimental Analysis on Rural Home Grid-Connected PV Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Rita Jorge Cerqueira Pinto ◽  
Sílvio José Pinto Simões Mariano ◽  
Maria do Rosário Alves Calado

Microgeneration is the small-scale generation of heat or electric power or both, by individuals or buildings to meet their own needs. Recently, microgeneration is being regarded as a means to decentralize the power production of renewable energies, reducing the impacts on the grid caused by unexpected energy demands. Given the increase in microgeneration facilities, determining the quantity of energy produced and the power quality assumes growing importance in low, medium, or high voltage facilities. This paper presents a power quality analysis of two different facilities with photovoltaic generation localized in a rural area of Portugal, describing the voltage and frequency behaviour, the harmonic contents, and the total harmonic distortion. Statistical data are presented regarding the number of voltage events and occurrence of dips and swells in both facilities as a percentage of rated voltage. We conclude that some PV systems can severely affect voltage quality, forcing the grid to work at and even above the maximum voltage standard limit.

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 790 ◽  
Author(s):  
Matej Žnidarec ◽  
Zvonimir Klaić ◽  
Damir Šljivac ◽  
Boris Dumnić

Expanding the number of photovoltaic (PV) systems integrated into a grid raises many concerns regarding protection, system safety, and power quality. In order to monitor the effects of the current harmonics generated by PV systems, this paper presents long-term current harmonic distortion prediction models. The proposed models use a multilayer perceptron neural network, a type of artificial neural network (ANN), with input parameters that are easy to measure in order to predict current harmonics. The models were trained with one-year worth of measurements of power quality at the point of common coupling of the PV system with the distribution network and the meteorological parameters measured at the test site. A total of six different models were developed, tested, and validated regarding a number of hidden layers and input parameters. The results show that the model with three input parameters and two hidden layers generates the best prediction performance.


Author(s):  
Ngo Xuan Cuong ◽  
Do Nhu Y

At present, small-scale grid-connected PV system is increasingly developed and used in many households. These small-scale PV system are often connected to grid using microinverter, because its advantages are low maintenance investment costs, ease of installation and operation and do not cause environmental pollution. The content of the article focuses on power quality analysis of the non-stored grid-connected PV system using microinverter. The research method in the paper is based on experiments on models and laboratory measurements. The analytical results will assess the power quality of grid-connected PV system using microinverter, thereby managers and operators to take measures to improve the power quality of the electrical system with grid-connected PV system.


2018 ◽  
Vol 1 (1) ◽  
pp. 57-65
Author(s):  
Abdul Ghaffar

Pakistan these days facing major energy crisis especially in the power sector. But to overcome these crisis major companies and the govt. of Pakistan is playing vital role so that supply could meet the demand. In association to this a major project National Power System Expansion Plan 2011-2030 has started which further increases the complexity of power system, but one thing in which these power companies are lagging is in the improvement of power quality. This paper introduces the power quality analysis of AC-DC converter topologies and their impact on input power system. Due to latest advancement in the technologies and its usage it is impossible to put barriers for the applications of power electronics topologies. These topologies are of different structure and causes harmonics when connected to the power system, these harmonics affects the power quality of the system network. Due to their wide usage it necessary to observe their impact on the input power system, which includes THD (total harmonic distortion) and distortion in the input power factor etc. This research work focuses on the power quality analysis of the power system. In this paper input THD of single-pulse, two-pulse and six-pulse controlled rectifier are analysed using FFT analysis in MATLAB and their effect on input power system are also discussed.


Author(s):  
Lakshmi Sravya Kanukolanu

Abstract: The standalone grid connected Photovoltaic (PV) systems have been gradually increasing for generation of electrical energy due to ever increasing fuel and coal prices, as well as the environmental issues posed by conventional power plants. In this transition phase, power quality is at its expense, resulting in damage to equipment or appliances and lost in production. Inadequate power quality can be caused by network failures and switching operations, which primarily cause voltage dips, interruptions, transients, and network disturbances from loads which primarily produce flicker i.e., rapid voltage changes, harmonics and phase imbalance. In this paper PV is used as an external DC source for D-STATCOM (Distributed Static Synchronous Compensator) which is a FACTS device that can maintain and repair power quality limitations such as power factor correction, voltage control, load balancing and harmonic reduction. The PV-STATCOM system inverter is implemented by impending MPPT method using P&O algorithm so as to provide DC link voltage control and to improve transient response along with counteracting power quality issues. MATLAB/Simulink based simulation results are presented for the proposed PVSTATCOM model. The simulation results proves that the PV-STATCOM system has better Total Harmonic Distortion (THD) and good reactive power compensation at different irradiance levels. Keywords: Photovoltaic (PV) systems, D-STATCOM (Distributed Static Synchronous Compensator), Total Harmonic Distortion (THD), MPPT (Maximum Power Point Tracking), FACTS (Flexible AC Transmission System)


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3665
Author(s):  
Łukasz Michalec ◽  
Michał Jasiński ◽  
Tomasz Sikorski ◽  
Zbigniew Leonowicz ◽  
Łukasz Jasiński ◽  
...  

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.


2020 ◽  
Vol 7 (3) ◽  
pp. 39-44
Author(s):  
Zahra Mulia Sari ◽  
Ahmad Hermawan ◽  
Sapto Wibowo

Abstract: The use of equipment with a high non-linear load causes a decrease in the quality of power (Power Quality) at Malang City Point Apartment. Power quality analysis is an important requirement in the electrical system and needs special attention to save energy and costs. Savings can be achieved by reducing or even eliminating losses resulting from the use of non-linear loads. This thesis aims to present the results of an analysis of power quality conditions at Malang City Point Apartments. This analysis includes voltage, current, voltage and current imbalance, power factor, current THD and measured voltage. The system is designed using Web - Based Power Quality Meter (PM 5110) as a measurement tool, then the results are analyzed and compared with existing standards to evaluate power quality in Malang City Point Apartments. Among the various power quality problems measured, it was found that the main problems of power quality in Malang City Point Apartments were the occurrence of overvoltages and current harmonic distortion. So it is necessary to do repairs on this to overcome the overvoltage by reducing the operation of equipment that has a large load and repairing neutral conductors. Furthermore, to reduce the system harmonics, it is designed by designing a single tuned passive filter and simulated using the ETAP software version 16.0.0.


In this work, the Impact of integration of multiple Photo Voltaic distributed generators (PV-DGs) on power quality of the distribution system is analyzed under static and dynamic loads. Major power quality parameters considered for the analysis are voltage deviation (VD), Total Real power and reactive power line losses (PT L & QT L) and Total Harmonic Distortion of Voltage at Buses (THDv ). Test system considered for the study is the IEEE-9 bus test system and types of loads considered are Static RL and Induction motors. Modeling and simulation of test system, PVs and Induction motor loads are carriedoutinMATLAB/SIMULINK software package


Author(s):  
Atul Kumar ◽  
Imran Khan

The emergent use of non-conventional energy resources in electrical power grid has initiated new challenge for the service load as concern to voltage balance, power quality issues and effective energy operation. Solar/ wind hybrid RES deliberated as the furthermost promising sources. Nevertheless standalone operations of distributed energy sources such as solar and wind not make sure of reliable power production principally owing to the randomness over the solar irradiance and accessibility of the wind. Hence, a combination of wind and solar energy production configuration can plan a highly reliable source of electrical energy. In This article, multi-level inverter (3 levels inverter) based grid tied hybrid solar- wind energy system based on a 3 level inverter is presented with the mitigation of power quality problems. In this work, analysis on simulation model is conceded to determine source current and voltage and percentage of total harmonic distortion. In particular, the power quality analysis is performed in grid tied hybrid solar and wind electrical power system using 3 level inverter.


2015 ◽  
Vol 752-753 ◽  
pp. 1158-1163 ◽  
Author(s):  
Abdul Rahim Abdullah ◽  
N.A. Abidullah ◽  
N.H. Shamsudin ◽  
N.H.H. Ahmad ◽  
M.H. Jopri

Power quality has become a greater concern nowadays. The increasing number of power electronics equipment contributes to the poor quality of electrical power supply. The power quality signals will affect manufacturing process, malfunction of equipment and economic losses. This paper presents the verification analysis of power quality signals classification system. The developed system is based on linear time-frequency distribution (TFD) which is spectrogram that represents the signals jointly in time-frequency representation (TFR). The TFD is very appropriate to analyze power quality signals that have magnitude and frequency variations. Parameters of the signal such as root mean square (RMS) and fundamental RMS, total waveform distortion (TWD), total harmonic distortion (THD) and total non-harmonic distortion (TnHD) of voltage signal are estimated from the TFR to identify the characteristics of the signal. Then, the signal characteristics are used as input for signal classifier to classify power quality signals. In addition, standard power line measurements are also calculated from voltage and current such as RMS and fundamental RMS voltage and current, real power, apparent power, reactive power, frequency and power factor. The power quality signals focused are swell, sag, interruption, harmonic, interharmonic, and transient based on IEEE Std. 1159-2009. The power quality analysis has been tested using a set of data and the results show that, the spectrogram gives high accuracy measurement of signal characteristics. However, the system offers lower accuracy compare to simulation due to the limitation of the system.


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