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Physical Sciences and Mathematics Commons

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Journal

TÜBİTAK

Power quality

2016

Articles 1 - 7 of 7

Full-Text Articles in Physical Sciences and Mathematics

A Generalized Design Method For Multifunction Converters Used In A Photovoltaic System, Trung Nhan Nguyen, An Luo Jan 2016

A Generalized Design Method For Multifunction Converters Used In A Photovoltaic System, Trung Nhan Nguyen, An Luo

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a general design method for multifunction converters using photovoltaic systems is proposed. With the proposed converter, the photovoltaic generator can provide flexibility, accuracy, and fast responses in both harmonic suppression and power injection modes in all cases of the grid-connected load. The controller for the proposed converter is designed based on the Lyapunov technique, along with the generalized algorithm for determining the global optimal values of the stability bounds. Therefore, the proposed converter can perform accurately and efficiently in the case of fixed system parameters as well as in the case of varying system parameters. Simulations and …


A Comprehensive Control Strategy Of Railway Power Quality Compensator For Ac Traction Power Supply Systems, Hamed Jafari Kaleybar, Siamak Farshad Jan 2016

A Comprehensive Control Strategy Of Railway Power Quality Compensator For Ac Traction Power Supply Systems, Hamed Jafari Kaleybar, Siamak Farshad

Turkish Journal of Electrical Engineering and Computer Sciences

The development of electrical railway systems leads to critical power quality problems in the power grid. This paper discusses a kind of half-bridge-based railway power quality compensator system (HBRPQC) that can compensate negative sequence currents, harmonics, and reactive power simultaneously. In order to keep the HBRPQC performance efficient for the different kinds of transformers used in traction power supply substations, a new multifunctional control strategy that performs better than previous methods is proposed. Due to the fast dynamicity of traction loads, a recessive self-tuning PI controller based on fuzzy logic is adopted in the current control system. The output control …


Empirical Mode Decomposition Application For Short-Term Flicker Severity, Yasemi̇n Önal, Ömer Nezi̇h Gerek, Doğan Gökhan Ece Jan 2016

Empirical Mode Decomposition Application For Short-Term Flicker Severity, Yasemi̇n Önal, Ömer Nezi̇h Gerek, Doğan Gökhan Ece

Turkish Journal of Electrical Engineering and Computer Sciences

In this article, an approach based on empirical mode decomposition (EMD) is suggested in order to calculate short-term flicker severity, Pst, in power systems. EMD is a new signal processing method used for the analysis of nonlinear and nonstationary signals. Pst is an important quantity in the electric power quality index defined by the International Electrotechnical Commission. In the suggested approach, the voltage signal is separated into intrinsic mode function components using EMD. These components are used for calculating the voltage flicker amplitude and frequency, and Pst is calculated as a result of the statistical evaluation of flicker amplitude. EMD …


Source Detection And Propagation Of Equal Frequency Voltage Flicker In Nonradial Power System, Abdolmajid Dejamkhooy, Ali Dastfan, Alireza Ahmadyfard Jan 2016

Source Detection And Propagation Of Equal Frequency Voltage Flicker In Nonradial Power System, Abdolmajid Dejamkhooy, Ali Dastfan, Alireza Ahmadyfard

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays electric power quality problems such as flicker (voltage fluctuation) are major concerns of electric companies and industrial consumers. Identification of flicker sources is an important stage in the flicker reduction process. Flicker source can be modeled as a nonlinear load whose admittance is intermittent and time-variant. In the steady state, fluctuation of voltage amplitude is a function of the impedance of flicker sources. In this paper, after calculating the gradient of voltage amplitudes and constructing a Jacobian matrix, criteria for flicker source detection are proposed. Therefore, by measuring voltage and current of each load in the power system, the …


Shunt Active Power Filter Control For Compensating Current Power Quality Problems In Three-Phase Three-Wire Systems Based On An Adaptive Notch Filter, Seyed Hossein Tabatabaei, Mehran Moslehi Bajestan, Alireza Jalilian Jan 2016

Shunt Active Power Filter Control For Compensating Current Power Quality Problems In Three-Phase Three-Wire Systems Based On An Adaptive Notch Filter, Seyed Hossein Tabatabaei, Mehran Moslehi Bajestan, Alireza Jalilian

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.


Power Quality Assessment In Different Wind Power Plant Models, Hamid Shariatpanah, Morteza Sabouri Kenari, Roohollah Fadaeinedjad Jan 2016

Power Quality Assessment In Different Wind Power Plant Models, Hamid Shariatpanah, Morteza Sabouri Kenari, Roohollah Fadaeinedjad

Turkish Journal of Electrical Engineering and Computer Sciences

In order to fully study the power quality of a grid-connected wind farm, a suitable model providing accurate output for wind farms is necessary. In this paper, different methods, which have been proposed in previous studies, are investigated with regard to the power quality problem using a squirrel-cage induction generator wind turbine. These models are different in terms of accuracy and simulation time. The question is: which method is more suitable for simulation of a wind farm? To answer this question, a criterion should be introduced to compare different modeling methods. Full turbine representation is introduced as the best criterion …


A New Method To Reduce The Adverse Effects Of Wind Power On Power Quality Using Reactive Power Compensating Capacitors, Seyed Navid Zahedi, Amir Amini, Hamid Falaghi Jan 2016

A New Method To Reduce The Adverse Effects Of Wind Power On Power Quality Using Reactive Power Compensating Capacitors, Seyed Navid Zahedi, Amir Amini, Hamid Falaghi

Turkish Journal of Electrical Engineering and Computer Sciences

The usage of distributed generation resources, particularly distributed generation with renewable sources, has increased to generate electrical power close to consumers. One of the factors that can reduce penetration of distributed generation resources is the limitation of power quality, such as harmonic distortions. Distributed generation sources, in addition to producing power, due to using of power electronic converters and changing the power flow, increase harmonic currents. On the other hand, local compensation of reactive power by parallel capacitor banks is one of the effective methods to reduce power system losses and harmonic distortions. Since the capacitor impedance varies at different …