A wavelet-based approach for reactive power metering in modern three-phase grids considering time-varying power quality disturbances

2012 ◽  
Vol 87 ◽  
pp. 31-38 ◽  
Author(s):  
W.G. Morsi
Keyword(s):  
Power Quality ◽  
Reactive Power ◽  
Time Varying ◽  
Three Phase ◽  
Power Quality Disturbances ◽  
Power Metering

Power Quality Issues and Solutions – Review

2015 ◽  
Vol 16 (4) ◽  
pp. 357-384 ◽  
Author(s):  
Suresh Mikkili ◽  
Anup Kumar Panda
Keyword(s):  
Power Quality ◽  
Power Distribution ◽  
Distribution Systems ◽  
Reactive Power ◽  
Electrical Power ◽  
Economic Loss ◽  
Nonlinear Loads ◽  
Broad Perspective ◽  
Three Phase ◽  
Quality Issues

Abstract Electrical power quality has been an important and growing problem because of the proliferation of nonlinear loads such as power electronic converters in typical power distribution systems in recent years. Particularly, voltage harmonics and power distribution equipment problems result from current harmonics produced by nonlinear loads. The Electronic equipment like, computers, battery chargers, electronic ballasts, variable frequency drives, and switch mode power supplies, generate perilous harmonics and cause enormous economic loss every year. Problems caused by power quality have great adverse economic impact on the utilities and customers. Due to that both power suppliers and power consumers are concerned about the power quality problems and compensation techniques. Power quality has become more and more serious with each passing day. As a result active power filter gains much more attention due to excellent harmonic and reactive power compensation in two-wire (single phase), three-wire (three-phase without neutral), and four-wire (three-phase with neutral) ac power networks with nonlinear loads. However, this is still a technology under development, and many new contributions and new control topologies have been reported in the last few years. It is aimed at providing a broad perspective on the status of APF technology to the researchers and application engineers dealing with power quality issues.

scholarly journals Research on Transient Power Quality of Large-capacity Electric Arc Furnace

2021 ◽  
Author(s):  
Liu Yang ◽  
Qinyue Tan ◽  
Di Xiong ◽  
Zhengguang Liu
Keyword(s):  
Power Quality ◽  
Reactive Power ◽  
Short Circuit ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Normal Operation ◽  
Arc Furnace ◽  
Three Phase ◽  
Transient Power Quality

The overrun of transient power quality index caused by the large-capacity electric arc furnace (EAF) has become a prominent problem affecting the safe and stable operation of the power system. (1) In this paper, the relationship between arc furnace volt-age and current is derived based on the different stages of arc combustion, and the random variation of chaotic phenomenon of the arc voltage are simulated. Established an EAF model suitable for the study of transient power quality problems. (2) Take 50t AC EAF as an example to analyze the reactive power impact and the influence on the point of common coupling (PCC) voltage caused by the three-phase short circuit of the electrode. The results show that the experimental results are consistent with the theoretical analysis, verifying the correctness and effectiveness of the model. (3) When the three-phase short-circuit occurs, the reactive power impact is nearly 6 times that of normal operation, the short-circuit current is 2.66 times that of normal operation, and the effective value of the PCC voltage has dropped by 40.37%, which provides a theoretical basis for real-time compensation of impulsive reactive power and improvement of the transient power quality of the EAF.

scholarly journals MODELING AND SIMULATION OF STATCOM FOR POWER QUALITY IMPROVEMENT

2021 ◽  
Vol 9 (2) ◽  
pp. 217-229
Author(s):  
Ch. Umamaheswararao, Et. al.
Keyword(s):  
Power Quality ◽  
Distribution Systems ◽  
Reactive Power ◽  
Reactive Power Compensation ◽  
Voltage Profile ◽  
Inductive Load ◽  
Linear Load ◽  
Three Phase ◽  
Quality Aspects ◽  
Wide Range

In power system, reactive power compensation is one of the important action to maintain better voltage profile, stability and decrease losses. STATCOM is feasible in terms of cost effective in wide range of problem solving capabilities among all Flexible AC Transmission system (FACTS) in both transmission and distribution levels. In this paper the synchronous rotating frame theory algorithm is used since it is easy to implement i.e. the rotating three phase quantities are converted into stationary components. So it requires less number of PI controllers and also calculations on the stationary quantities are easy than to do calculations on instantaneous quantities and the modeling of STATCOM is done.  This project focuses on improvement of power quality in a three phase three wire system with a non-linear load i.e., three phase bridge rectifier and a parallel inductive load. Some power quality aspects like reactive power compensation of linear load, better Total Harmonic Distortion (THD) performance and the power factor improvement are achieved. The result shows the THD of input current achieved as per the IEEE 519-1992 standard. It is observed that STATCOM gives effective compensation for reactive power variation and hence the power quality of distribution systems improved.

scholarly journals Analysis of Three Phase 3-Level NPC Voltage Source Converter for AC-DC Conversion

2020 ◽  
Vol 06 (09) ◽  
pp. 144-148
Author(s):  
A Divya Teja and Dr. N Sambasiva Rao
Keyword(s):  
Power Quality ◽  
Power Flow ◽  
Reactive Power ◽  
Neutral Point ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Phase 3 ◽  
Control Techniques ◽  
Point Potential ◽  
Three Phase

The use of power electronic converters influences the generation of harmonics and reactive power flow in power system. Therefore, three-phase multilevel improved power quality AC-DC converters are gaining lot of popularity in power conversion applications. This work deals with critical problem of multilevel structure i.e neutral point potential (NPP) variation. In this paper, a simplified current controlled scheme is presented to ensure unity power factor operation. Neutral point potential (NPP) of three-phase, 3-level NPC AC-DC converter is controlled by modifying control signal in the controller using NPP regulator. An auxiliary circuit is being presented in this paper as an alternative option for controlling the neutral point potential of the converter. Comparison has been carried out between these control techniques in terms of power quality. A complete mathematical model is presented for better understanding of both techniques used for NPP control. The presented control techniques has been verified through simulation investigations and validated

Modelling and Analysis of PV-Based Shunt Active Filter with BESS and Conservative Power Theory for Enhancing Power Quality

2019 ◽  
Vol 20 (6) ◽  
Author(s):  
Gomathi Ramalingam ◽  
Ajay Kumar Choudhary ◽  
Suresh Mikkili
Keyword(s):  
Power Quality ◽  
Reactive Power ◽  
Reactive Power Compensation ◽  
Active Power ◽  
Active Filters ◽  
Shunt Active Filter ◽  
Three Phase ◽  
Quality Issues ◽  
Conservative Power Theory ◽  
Conservative Power

Abstract Power Quality has always been a major concern ever since the increase in the usage of many power electronic loads such as Personal Computers (PCs), TVs, variable frequency drives in nearly every household. These loads are a major source of harmonics into the distribution system. Unbalanced Three-phase loads or different single-phase loads result in unbalance in the three-phase voltages and currents in the grid. Equipment damage, Loss of data, nuisance tripping, overheating of wires, relay tripping are few of the major issues caused due to power quality. Also, there is an increase in the awareness about the various power quality issues as well as its ill-effects amongst the consumers. Hence, it is essential to improve the quality of the power supplied. Active and Passive filters play a huge role in the mitigation of power quality issues. In recent years, usage of active filters has increased because tuning is possible for various harmonic elimination and active filters when combined with a storage system can provide active as well as reactive power compensation. The fast depletion of non-renewable sources of energy and its effect on the environment has shifted the focus on the usage of non-renewable energy sources such as solar energy, wind energy, etc for the production of electricity. In this research work, solar energy is combined with shunt active filter for the mitigation of various power quality issues occurring in a grid-connected non-linear and unbalanced three-phase load. The active power filter will provide reactive power compensation to the non-linear load and active power delivery for unbalanced loads such the grid current and voltage will remain balanced and the stress on the grid is reduced while meeting the load demand. A battery system is also integrated to store the excess energy that may be generated by the Photo-Voltaic(PV) array and acts as a source of energy when PV array output is low or nil. Conservative Power Theory is used for controlling the power injection into the system by the Voltage Source Converter(VSC). The proposed system is verified using MATLAB/SIMULINK.

A New Control Algorithm for Three-Phase, Four-Wire Unified Power Quality Conditioner (UPQC) in Distributing Systems

2012 ◽  
Vol 433-440 ◽  
pp. 6731-6736
Author(s):  
Chandrakant L. Bhattar ◽  
Vilas N. Ghate
Keyword(s):  
Power Quality ◽  
Distribution System ◽  
Control Algorithm ◽  
Reactive Power ◽  
Voltage Regulation ◽  
Voltage Source ◽  
Voltage Source Inverter ◽  
Unified Power Quality Conditioner ◽  
Three Phase ◽  
Power Quality Conditioner

This paper presents the new control algorithm for three-phase, four-wire distributing system using unified power quality conditioner (UPQC). The UPQC, a combination of series and shunt active filter (AF) with common dc link, is one of the best solution towards the compensation of voltage sag, swell problems and also compensate voltage flicker/imbalance, reactive power, negative sequence current and maintain zero voltage regulation (ZVR) at the point of common coupling (PCC) on distribution system. The series AF is seen by using a three-phase, three leg voltage source inverter (VSI) and the shunt AF is of a three-phase, four leg voltage source inverter (VSI). The proposed model of the UPQC is developed in the MATLAB/SIMULINK environment and the simulation results prove the power quality improvement in the system.

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