Approach Method to Evaluate the Total Harmonic Distortion for a System Has Multiple Nonlinear Loads

2015 ◽  
Vol 4 (11) ◽  
pp. 618-624
Author(s):  
H. A. Mohamed
Keyword(s):  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Nonlinear Loads ◽  
Approach Method

Analysis on Harmonics Caused by Connecting Electric Vehicle Chargers with Power Network

2013 ◽  
Vol 724-725 ◽  
pp. 1393-1397
Author(s):  
Xiang Zhen Li ◽  
Guang Ming Hu ◽  
Peng Xin Hou ◽  
Yu Bo Fan ◽  
Chun Lin Guo
Keyword(s):  
Electric Vehicle ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Power Network ◽  
Nonlinear Loads ◽  
Harmonic Current ◽  
Current Ratio ◽  
Harmonic Pollution ◽  
Charging Stations ◽  
The Impact

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.

scholarly journals Power Quality Improvement by Reduction of Total Harmonic Distortion (THD) using PWM Inverter

2020 ◽  
Vol 9 (2) ◽  
pp. 1641-1643
Keyword(s):  
Quality Improvement ◽  
Power Quality ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Nonlinear Loads ◽  
Pwm Inverter ◽  
System A ◽  
Power Quality Improvement ◽  
Simulation Results ◽  
And Performance

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.

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.

Design of Efficient Power Filter with Reduced Distortion Using Control Algorithm

IJOSTHE ◽  
2020 ◽  
pp. 1-10
Author(s):  
Rahul Dhakad ◽  
Dr. Rakesh Saxena
Keyword(s):  
Distribution System ◽  
Output Voltage ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Renewable Energy Resources ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Power Filter ◽  
Distortion Level ◽  
Voltage Output

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.

scholarly journals Harmonic Analysis of Grid-Connected Solar PV Systems with Nonlinear Household Loads in Low-Voltage Distribution Networks

2021 ◽  
Vol 13 (7) ◽  
pp. 3709
Author(s):  
Syed Muhammad Ahsan ◽  
Hassan Abbas Khan ◽  
Akhtar Hussain ◽  
Sarmad Tariq ◽  
Nauman Ahmad Zaffar
Keyword(s):  
Low Voltage ◽  
Harmonic Distortion ◽  
Distribution Networks ◽  
Total Harmonic Distortion ◽  
Base Case ◽  
Solar Pv ◽  
Voltage Profile ◽  
Nonlinear Loads ◽  
Pv Systems ◽  
Pv Penetration

Grid-connected rooftop and ground-mounted solar photovoltaics (PV) systems have gained attraction globally in recent years due to (a) reduced PV module prices, (b) maturing inverter technology, and (c) incentives through feed-in tariff (FiT) or net metering. The large penetration of grid-connected PVs coupled with nonlinear loads and bidirectional power flows impacts grid voltage levels and total harmonic distortion (THD) at the low-voltage (LV) distribution feeder. In this study, LV power quality issues with significant nonlinear loads were evaluated at the point of common coupling (PCC). Various cases of PV penetration (0 to 100%) were evaluated for practical feeder data in a weak grid environment and tested at the radial modified IEEE-34 bus system to evaluate total harmonic distortion in the current (THDi) and voltage (THDv) at PCC along with the seasonal variations. Results showed lower active, reactive, and apparent power losses of 1.9, 2.6, and 3.3%, respectively, with 50% solar PV penetration in the LV network as the voltage profile of the LV network was significantly improved compared to the base case of no solar. Further, with 50% PV penetration, THDi and THDv at PCC were noted as 10.2 and 5.2%, respectively, which is within the IEEE benchmarks at LV.

scholarly journals Non-Intrusive Identification of Load Patterns in Smart Homes Using Percentage Total Harmonic Distortion

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4628 ◽  
Author(s):  
Hari Prasad Devarapalli ◽  
V. S. S. Siva Sarma Dhanikonda ◽  
Sitarama Brahmam Gunturi
Keyword(s):  
Light Emitting Diode ◽  
Harmonic Distortion ◽  
Electricity Consumption ◽  
Side Lobe ◽  
Vital Role ◽  
Total Harmonic Distortion ◽  
Distribution Grid ◽  
Digital Controllers ◽  
Nonlinear Loads ◽  
Harmonic Pollution

Demand Response (DR) plays a vital role in a smart grid, helping consumers plan their usage patterns and optimize electricity consumption and also reduce harmonic pollution in a distribution grid without compromising on their needs. The first step of DR is the disaggregation of loads and identifying them individually. The literature suggests that this is accomplished through electric features. Present-day households are using modern power electronic-based nonlinear loads such as LED (Light Emitting Diode) lamps, electronic regulators and digital controllers to reduce the electricity consumption. Furthermore, usage of SMPS (Switched-Mode Power Supply) for computing and mobile phone chargers is increasing in every home. These nonlinear loads, while reducing electricity consumption, also introduce harmonic pollution into the distribution grid. This article presents a deterministic approach to the non-intrusive identification of load patterns using percentage Total Harmonic Distortion (THD) for DR management from a Power Quality perspective. The percentage THD of various combinations of loads is estimated by enhanced dual-spectrum line interpolated FFT (Fast Fourier Transform) with a four-term minimal side-lobe window using a LabVIEW-based hardware setup in real time. The results demonstrate that percentage THD identifies a different combination of loads effectively and advocates alternate load combinations for recommending to the consumer to reduce harmonic pollution in the distribution grid.

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