Prediction of total harmonic distortion based on harmonic modeling of nonlinear loads using measured data for parameter estimation

Author(s):  
Daniel S. Braga ◽  
Patricia R. S. Jota
2011 ◽  
Vol 131 (12) ◽  
pp. 936-944 ◽  
Author(s):  
Shoji Kawasaki ◽  
Kazuki Shimoda ◽  
Motohiro Tanaka ◽  
Hisao Taoka ◽  
Junya Matsuki ◽  
...  

2013 ◽  
Vol 724-725 ◽  
pp. 1393-1397
Author(s):  
Xiang Zhen Li ◽  
Guang Ming Hu ◽  
Peng Xin Hou ◽  
Yu Bo Fan ◽  
Chun Lin Guo

As a class of nonlinear loads in the power system, electric vehicle chargers will produce a certain harmonic pollution for the grid. Before the construction of charging stations, it is necessary for electric vehicle charger (station) connected to the grid to simulate and predict harmonics. The models of single charger and charge station are built separately in order to simulate and analysis the impact of a single and multiple chargers on power quality. The factors of the harmonic current ratio (HRI) and the current total harmonic distortion (THDI) varied with the charging power and the number of the chargers are discussed and analyzed. The generation mechanism of harmonic counteraction and interaction between the chargers are analyzed. The simulation results show that: because of the impedance of the system and the transformer, the harmonic current ratio (HRI) and the current total harmonic distortion (THDI) both increase firstly to some extent and subsequently decrease gently with the increase of the number of the chargers in the same power charging. This phenomenon has nothing to do with the harmonic counteraction and how that happen is discussed and analysis in this paper. And the phenomenon of harmonics interaction and counteraction occurs with the increase of the number of the chargers in different power charging, and the current total harmonic distortion (THDI) declines and tends to maintain a relatively stable value.


In this paper, a PWM inverter is proposed for improvement of power quality i.e., reduction of total harmonic distortion (THD). The power quality problems reduce the lifetime and performance of equipments. The proposed system reduces the THD which is generated from the nonlinear loads. Because presence of harmonics leads to problems like overheating, failure of insulation etc. Here the simulation results of the proposed system is studied using MATLAB SIMULINK. Using the system, a lower THD is achieved which shows the effectiveness of the system.


2012 ◽  
Vol 182 (3) ◽  
pp. 19-29
Author(s):  
Shoji Kawasaki ◽  
Kazuki Shimoda ◽  
Motohiro Tanaka ◽  
Hisao Taoka ◽  
Junya Matsuki ◽  
...  

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.


IJOSTHE ◽  
2020 ◽  
pp. 1-10
Author(s):  
Rahul Dhakad ◽  
Dr. Rakesh Saxena

The electrical distribution system is facing undesirable power quality disturbances due to different types of linear/nonlinear loads on the supply system. The objective of the project is to reduce the distortion level in voltage or current input to the load and at the output of the filter. To design a simple but highly viable hybrid active power buffer that is capable of feeding less distorted voltage to the nonlinear load model. To present an optimal controlling of these buffers so as to minimize the voltage distortion by designing a different algorithm for the same. Comparing the THD levels of the output voltage waveform with the standard controlling method with the proposed control design to further enhance the proposed design such that it is practically feasible to be implemented in grid system having renewable energy resources. In this work, a power filter has been designed using different algorithms with an objective to reduce the Total Harmonic Distortion in the voltage output waveforms. The total harmonic distortion in the voltage output waveform being fed to the load using only the PQ_RLS algorithm is found to be 2.18 %. In the case of the output voltage from the power buffer using PQ_RLS algorithm, the THD level is 0.17 %. The distortion level in the output voltage waveforms in both the cases being fed to the load when compared, it is found that RLS algorithm in combination with PQ algorithm is more effective in reducing the distortion as compared to standard RLS method or PQ method.


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