Showing 11 results for Power Quality
A. Hajizadeh, M. Aliakbar-Golkar,
Volume 3, Issue 1 (1-2007)
Abstract
The operation of Fuel Cell Distributed Generation (FCDG) systems in
distribution systems is introduced by modeling, controller design, and simulation study of a
Solid Oxide Fuel Cell (SOFC) distributed generation (DG) system. The physical model of
the fuel cell stack and dynamic models of power conditioning units are described. Then,
suitable control architecture based on fuzzy logic control for the overall system is presented
in order to active power control and power quality improvement. A MATLAB/Simulink
simulation model is developed for the SOFC DG system by combining the individual
component models and the controllers designed for the power conditioning units.
Simulation results are given to show the overall system performance including active power
control and voltage regulation capability of the distribution system.
R. Noroozian, M. Abedi, G. B. Gharehpetian, S. H. Hosseini,
Volume 3, Issue 3 (7-2007)
Abstract
This paper describes a DC isolated network which is fed with Distributed
Generation (DG) from photovoltaic (PV) renewable sources for supplying unbalanced AC
loads. The battery energy storage bank has been connected to the DC network via DC/DC
converter to control the voltage of the network and optimize the operation of the PV
generation units. The PV arrays are connected to the DC network via its own DC/DC
converter to ensure the required power flow. The unbalanced AC loads are connected to the
DC network via its own DC/AC converter. This paper proposes a novel control strategy for
storage converter which has a DC voltage droop regulator. Also a novel control system
based on Park rotating frame has been proposed for DC/AC converters. In this paper, the
proposed operation method is demonstrated by simulation of power transfer between PV
arrays, unbalanced AC loads and battery unit. The simulation results based on
PSCAD/EMTDC software show that DC isolated distribution system including PV
generation systems can provide the high power quality to supplying unbalanced AC loads.
H. Fallah Khoshkar, A. Doroudi, M. Mohebbi,
Volume 10, Issue 4 (12-2014)
Abstract
This paper studies the effects of symmetrical voltage sags on the operational characteristics of a Permanent Magnet Synchronous Motor (PMSM) by Finite Element Method (FEM). Voltage sags may cause high torque pulsations which can damage the shaft or equipment connected to the motor. By recognizing the critical voltage sags, sags that produce hazardous torque variations could be prevented. Simulations results will be provided and the critical voltage sags are recognized. A simple theoretical analysis will also be presented to obtain a qualitative understanding of the phenomena occurring in PMSM during symmetrical voltage sags
M. K. Saini, R. K. Beniwal,
Volume 14, Issue 2 (6-2018)
Abstract
This paper presents a new framework based on modified EMD method for detection of single and multiple PQ issues. In modified EMD, DWT precedes traditional EMD process. This scheme makes EMD better by eliminating the mode mixing problem. This is a two step algorithm; in the first step, input PQ signal is decomposed in low and high frequency components using DWT. In the second stage, the low frequency component is further processed with EMD technique to get IMFs. Eight features are extracted from IMFs of low frequency component. Unlike low frequency component, features are directly extracted from the high frequency component. All these features form feature vector which is fed to PNN classifier for classification of PQ issues. For comparative analysis of performance of PNN, results are compared with SVM classifier. Moreover, performance of proposed methodology is also validated with noisy PQ signals. PNN has outperformed SVM for both noiseless and noisy PQ signals.
R. Shariatinasab, M. Rasuli, J. Gholinezhad,
Volume 15, Issue 1 (3-2019)
Abstract
In this paper a novel method based on evolutionary algorithms is presented to estimate the harmonic components. In general, the optimization of the harmonic estimation process is a multi-component problem, in which evaluation of the phase and harmonic frequency is the nonlinear part of the problem and is solved based on the mathematical and evolutionary methods; while estimation of amplitude of the harmonic component is a linear issue that is performed by combining the least squares method with the aforementioned approaches. In this paper, firstly, the optimal estimation of integer harmonic components has been introduced based on the improved shuffled frog leaping algorithm (ISFLA) in the presence of two types of noise. The obtained results present the lower error of the proposed method than to IGHS, FBF PSO, GA and FFT methods. Thereafter, the effectiveness of the presented algorithm in optimal estimation of frequency, phase, and amplitude of the integer and non-integer harmonics are investigated. The optimization of the estimation of various harmonic components under different conditions using ISFLA leads to an improvement in the assessment of power quality in power systems especially in the distribution networks, considering a lot of the nonlinear loads and harmonic resources connected to the network.
B. Tousi, M. Farhadi-Kangarlu, M. Farzinnia,
Volume 15, Issue 3 (9-2019)
Abstract
In this paper a new topology for Dynamic Voltage Restorer (DVR) with high frequency link is proposed. This topology is able to compensate different types of voltage disturbances such as voltage sag, voltage swell and voltage harmonics. According to the obtained equations, this topology operates as a controllable current source to charge the series capacitor. Due to using High Frequency Transformer (HFT), the volume and the weight of the proposed DVR is decreased in comparison with conventional DVRs. This topology contains two ac/ac converters which are using in the input and output of the device. The absence of DC link capacitors and storage elements is the other advantage of using the proposed structure. In order to verify the claimed features, the proposed topology has been simulated by PSCAD/EMTDC software and examined under several disturbance conditions. In addition, an experimental prototype has been designed and tested. The results of the simulation and experimental cases are presented.
M. Habibolahzadeh, A. Jalilian,
Volume 17, Issue 2 (6-2021)
Abstract
Electric traction trains are huge non-linear single-phase loads influencing adversely on power quality parameters on the grid side. Hybrid power quality conditioner (HPQC) has been utilized to compensate current unbalance, harmonics, and low power factor in the co-phase traction system simultaneously. By incrementing the traction load, the rating of the HPQC increases and may constraints its application. In this paper, a C-type filter is designed to compensate for some part of the load reactive power while the HPQC compensates the remaining part of the load reactive power. Hence, the capacity of the HPQC is reduced in full compensation (FC) mode compared to the conventional configuration. The satisfactory performance of the HPQC is associated with its DC-link operating voltage. Therefore, the Genetic algorithm (G.A) is adopted to optimize the DC-link voltage performance. Simulation verifications are performed to illustrate the usefulness of the proposed configuration. The simulation results show an 18.86% reduction in the rating of the HPQC with optimized DC-link voltage.
R. Gandotra, K. Pal,
Volume 18, Issue 3 (9-2022)
Abstract
The growing demand increases the maximum utilization of transmission and distribution lines which causes overloading, high losses, instability, contingency, and congestion. To enhance the performance of AC transmission and distribution systems FACTS devices are used. These devices assist in solving different issues of transmission lines such as instability, congestion, power flow, and power losses. Advancement in developed technology leads to the development of special application-based FACTS controllers. The main issues are concerned while placing the FACTS controller in the transmission and distribution lines to maximize the flow of power. Various methods like analytic method, arithmetic programming approaches, meta-heuristic optimization approaches, and hybrid approaches are being employed for the optimal location of FACTS controllers. This paper presents a review of various types of FACTS controllers available with both analytical and meta-heuristic optimization methods for the optimal placement of FACTS controllers. This paper also presents a review of various applications of FACTS devices such as stability improvement, power quality, and congestion management which are the main issues in smart power systems. Today’s smart power systems comprise the smart grids with smart meters and ensure continuous high quality of power to the consumers.
P. Lakshman Naik, H. Jafari, T. Sudhakar Babu, A. Anil, S. Venkata Padmavathi, D. Nazarpour,
Volume 19, Issue 2 (6-2023)
Abstract
This paper demonstrates an enhancement of power quality in grid integrated systems with the help of the proposed control strategy for voltage source converter based active power filters. The Shunt Active Power filters (SAPF) are extensively utilized in modern grid integrated systems to diminish the power quality concerns associated with it. The SAPF is one of the various power filters, which has better dynamic performance. The SAPF requires an accurate control strategy that provides robust performance under source and loads unbalance conditions. The proposed control scheme is responsible for generating the gate signals to activate the operation of Voltage Source Converter (VSC) based Active Power Filter. Thus, the performance of mitigation of harmonics of source current principally depends on the adopted algorithm. The present paper represents a performance study of a control scheme to mitigate power quality issues in the grid integrated system. The proposed system is modelled and simulated in MATLAB-Simulink in Simpower system block set.
Malik Khalid , Baharuddin Ismail , Chanuri Charin, Arnawan Hasibuan , Abd Alazeez Almaleeh,
Volume 21, Issue 2 (6-2025)
Abstract
This paper presents a comprehensive research endeavor focused on evaluating the influence of renewable energy, particularly wind power, on power quality within the context of Jordan's electrical grid. The escalating global demand for energy, coupled with the imperative to curb greenhouse gas emissions, has propelled the rapid adoption of renewable energy sources. Against this backdrop, the study aims to meticulously analyze the effects of wind energy projects on power quality parameters such as voltage fluctuations, harmonics, and power factor. Through an extensive methodology comprising data collection, rigorous analysis, and advanced simulation techniques, actionable insights are provided into the seamless integration of renewable energy into existing grid infrastructures. In this work, power quality parameters like Total Harmonic Distortion, flickers, power frequency, Crest factor, and voltage unbalance are measured at Al-Tafilah Governorate, Jordan. The significance of this study lies in its contribution to the development of strategies and guidelines essential for policymakers, engineers, and stakeholders. By fostering a deeper understanding of the interplay between renewable energy and power quality, the findings aim to facilitate the establishment of a sustainable and resilient energy system in Jordan. Beyond mitigating climate change and enhancing energy security, this research underscores the pivotal role of renewable energy in ushering in a greener, cleaner future for generations to come.
Mohd Zulhisham Mohd Radzi, Baharuddin Ismail, Muhammad Mokhzaini Azizan,
Volume 21, Issue 2 (6-2025)
Abstract
The rise of nonlinear and unbalanced loads in modern electrical systems poses challenges to power quality management. These loads, prevalent in electronic devices and industrial equipment, induce harmonic distortions and unbalance, adversely affecting the neutral conductor in three-phase systems. This study investigates these effects through modeling and simulation using MATLAB/Simulink and symmetrical components theory for detailed power quality analysis. The research focuses on three scenarios: nonlinear loads, unbalanced loads, and combined nonlinear-unbalanced loads. Simulation results show that nonlinear loads significantly increase harmonic content, while unbalanced loads lead to notable power quality deviations. When combined, these conditions exacerbate harmonic distortions and unbalance, resulting in higher neutral current magnitudes. Key findings highlight the severe impact of combined load conditions on the neutral conductor, emphasizing the need for accurate modeling and analysis. This research provides valuable insights and practical recommendations for addressing the challenges of nonlinear and unbalanced loads, contributing to improved power system design and management.
