Electrical arc is a stochastic process; witch is the principal cause of power quality problems, i... more Electrical arc is a stochastic process; witch is the principal cause of power quality problems, including voltages dips, harmonic distortion, unbalance loads and flicker. So it is difficult to make an appropriate model for an EAF. The factors that effect EAF operation are the melting or refining materials, melting stage, electrode position (arc length), electrode arm control and short circuit power of the feeder. So arc voltages, current and power are defined as a nonlinear function of the arc length. In this article we propose our own empirical function of the EAF and model for the mean stages of the melting process. This study is important, because improvement of Electric Arc means high productivity (in tons/year) and lowest possible costs arising form energy consumption, electrode and refractory wear.
In this article, a solution to increase the reliability of powering the auxiliary equipment of po... more In this article, a solution to increase the reliability of powering the auxiliary equipment of power stations of major sources based on photovoltaic energy was examined. The investigations are carried out on the transformer station 220KV/90KV/60KV/30kV located at El Hadjar -Algeria, which uses the auxiliary service transformers 30/0.4 kV for its own power needs. Since the network itself provides this power, the station's low voltage equipment will felt any disturbance on the network (lack or drop of voltage, etc …). The function of the auxiliary service transformers 30/0.4 kV is to provide the energy required for the operation of network monitoring equipment (protection relays), high voltage (HV) controls (circuit breakers, disconnections, load adjuster), Signalizations, Telecommunications equipment (high frequency: HF network and optic fibers), Digital Control System. This whole system is intimately linked to the network. Hence the idea of an independent external source that will provide the energy necessary for its operation even in the case of a blackout. In addition, it will save the energy drawn from the grid for the needs of the interconnection transformer station.
Renewable energy, especially solar photovoltaic (PV) panels, have been widely integrated into ene... more Renewable energy, especially solar photovoltaic (PV) panels, have been widely integrated into energy systems, indeed, this technology is eco-friendly and available almost everywhere. However, these systems exhibit some challenges in regards their performance. They must always track the maximum power point (MPP) to provide the highest power. This work investigates a novel maximum power point tracking (MPPT) procedure. In the suggested tracking system, a novel controller is applied to establish different operating regions. In both regions, the step is changed depending on the closeness to the MPP. Due to this technique, some disadvantages of the incremental conductance (IncCond) approach are avoided. The proposed method offers reliable and stable behaviour under rapidly changing atmospheric conditions. Moreover, it is easy as it does not need additional sensors. The theoretical assessment discussed in this investigation is validated by simulations via MATLAB/Simulink and experimental ...
Diagnostic goal of transformers in service is to detect the winding or the core in fault. Transfo... more Diagnostic goal of transformers in service is to detect the winding or the core in fault. Transformers are valuable equipment which makes a major contribution to the supply security of a power system. Consequently, it is of great importance to minimize the frequency and duration of unwanted outages of power transformers. So, Frequency Response Analysis (FRA) is found to be a useful tool for reliable detection of incipient mechanical fault in a transformer, by finding winding or core defects. The authors propose as first part of this article, the coupled circuits method, because, it gives most possible exhaustive modelling of transformers. And as second part of this work, the application of FRA in low frequency in order to improve and simplify the response reading. This study can be useful as a base data for the other transformers of the same categories intended for distribution grid.
International Journal of Applied Power Engineering, 2015
This paper deals the power control for three-level voltage source inverter NPC-VSI feeds the roto... more This paper deals the power control for three-level voltage source inverter NPC-VSI feeds the rotor of the doubly fed induction generator ‘DFIG’ based wind power generation system. This converter allows controlling the rotor voltage in magnitude and phase angle with a high flexibility and can therefore be used for active and reactive power control of DFIG. The control is especially designed to reduce the harmonic distortion of the generated currents and active power ripples of the classical control. In addition, it’s convenient for high power drive and variable speed generator applications with constant switching frequency. The detailed operation principle and simulation results for 3 MW of DFIG are also discussed.
2021 IEEE 1st International Maghreb Meeting of the Conference on Sciences and Techniques of Automatic Control and Computer Engineering MI-STA, 2021
For interconnection networks, stability and security of networks in each country are of major imp... more For interconnection networks, stability and security of networks in each country are of major importance for companies of generation and transmission of electrical energy and an objective of several research laboratories. For obvious technical and economic reasons, it is not possible to build networks free of malfunctions; they are particularly exposed at least to natural aggressions like lightning. Networks are therefore affected by disturbances that might affect the equipment durability and the quality of service provided and despite the existence of many traditional technical methods of stability, one always look for new methods that can improve the service quality. For this purpose, we will try in this thesis to address this issue through initially a thorough description of the interconnection network Algeria / Tunis then using the recorded incidents statistics, we focused our study on the disturbed line 220KV between AL Aouinette and Tajerouine with a proposed solution is to install a power transformer-type shifter "PST"
Global Journal of Computer Sciences: Theory and Research, 2018
Diagnostic goal of transformers in service is to detect the winding or the core in fault. Transfo... more Diagnostic goal of transformers in service is to detect the winding or the core in fault. Transformers are valuable equipment which makes a major contribution to the supply security of a power system. Consequently, it is of great importance to disequilibria the three phases courant of power transformers. So, vector diagram Analysis is useful tool for reliable detection of incipient mechanical fault in a transformer, by finding winding or core defects. The authors propose this article, the coupled circuits method, because, it gives most possible exhaustive modelling of transformers. Measurement courant homopolaire in order to improve and simplify the response for à faults transformer.This study can be useful as a base data for the other transformers of the same categories intended for distribution grid. Keywords—Diagnostic; Short-Circuit; Transformer Faults; unbalanced current.
Electrical arc is a stochastic process; witch is the principal cause of power quality problems, i... more Electrical arc is a stochastic process; witch is the principal cause of power quality problems, including voltages dips, harmonic distortion, unbalance loads and flicker. So it is difficult to make an appropriate model for an EAF. The factors that effect EAF operation are the melting or refining materials, melting stage, electrode position (arc length), electrode arm control and short circuit power of the feeder. So arc voltages, current and power are defined as a nonlinear function of the arc length. In this article we propose our own empirical function of the EAF and model for the mean stages of the melting process. This study is important, because improvement of Electric Arc means high productivity (in tons/year) and lowest possible costs arising form energy consumption, electrode and refractory wear.
In this article, a solution to increase the reliability of powering the auxiliary equipment of po... more In this article, a solution to increase the reliability of powering the auxiliary equipment of power stations of major sources based on photovoltaic energy was examined. The investigations are carried out on the transformer station 220KV/90KV/60KV/30kV located at El Hadjar -Algeria, which uses the auxiliary service transformers 30/0.4 kV for its own power needs. Since the network itself provides this power, the station's low voltage equipment will felt any disturbance on the network (lack or drop of voltage, etc …). The function of the auxiliary service transformers 30/0.4 kV is to provide the energy required for the operation of network monitoring equipment (protection relays), high voltage (HV) controls (circuit breakers, disconnections, load adjuster), Signalizations, Telecommunications equipment (high frequency: HF network and optic fibers), Digital Control System. This whole system is intimately linked to the network. Hence the idea of an independent external source that will provide the energy necessary for its operation even in the case of a blackout. In addition, it will save the energy drawn from the grid for the needs of the interconnection transformer station.
Renewable energy, especially solar photovoltaic (PV) panels, have been widely integrated into ene... more Renewable energy, especially solar photovoltaic (PV) panels, have been widely integrated into energy systems, indeed, this technology is eco-friendly and available almost everywhere. However, these systems exhibit some challenges in regards their performance. They must always track the maximum power point (MPP) to provide the highest power. This work investigates a novel maximum power point tracking (MPPT) procedure. In the suggested tracking system, a novel controller is applied to establish different operating regions. In both regions, the step is changed depending on the closeness to the MPP. Due to this technique, some disadvantages of the incremental conductance (IncCond) approach are avoided. The proposed method offers reliable and stable behaviour under rapidly changing atmospheric conditions. Moreover, it is easy as it does not need additional sensors. The theoretical assessment discussed in this investigation is validated by simulations via MATLAB/Simulink and experimental ...
Diagnostic goal of transformers in service is to detect the winding or the core in fault. Transfo... more Diagnostic goal of transformers in service is to detect the winding or the core in fault. Transformers are valuable equipment which makes a major contribution to the supply security of a power system. Consequently, it is of great importance to minimize the frequency and duration of unwanted outages of power transformers. So, Frequency Response Analysis (FRA) is found to be a useful tool for reliable detection of incipient mechanical fault in a transformer, by finding winding or core defects. The authors propose as first part of this article, the coupled circuits method, because, it gives most possible exhaustive modelling of transformers. And as second part of this work, the application of FRA in low frequency in order to improve and simplify the response reading. This study can be useful as a base data for the other transformers of the same categories intended for distribution grid.
International Journal of Applied Power Engineering, 2015
This paper deals the power control for three-level voltage source inverter NPC-VSI feeds the roto... more This paper deals the power control for three-level voltage source inverter NPC-VSI feeds the rotor of the doubly fed induction generator ‘DFIG’ based wind power generation system. This converter allows controlling the rotor voltage in magnitude and phase angle with a high flexibility and can therefore be used for active and reactive power control of DFIG. The control is especially designed to reduce the harmonic distortion of the generated currents and active power ripples of the classical control. In addition, it’s convenient for high power drive and variable speed generator applications with constant switching frequency. The detailed operation principle and simulation results for 3 MW of DFIG are also discussed.
2021 IEEE 1st International Maghreb Meeting of the Conference on Sciences and Techniques of Automatic Control and Computer Engineering MI-STA, 2021
For interconnection networks, stability and security of networks in each country are of major imp... more For interconnection networks, stability and security of networks in each country are of major importance for companies of generation and transmission of electrical energy and an objective of several research laboratories. For obvious technical and economic reasons, it is not possible to build networks free of malfunctions; they are particularly exposed at least to natural aggressions like lightning. Networks are therefore affected by disturbances that might affect the equipment durability and the quality of service provided and despite the existence of many traditional technical methods of stability, one always look for new methods that can improve the service quality. For this purpose, we will try in this thesis to address this issue through initially a thorough description of the interconnection network Algeria / Tunis then using the recorded incidents statistics, we focused our study on the disturbed line 220KV between AL Aouinette and Tajerouine with a proposed solution is to install a power transformer-type shifter "PST"
Global Journal of Computer Sciences: Theory and Research, 2018
Diagnostic goal of transformers in service is to detect the winding or the core in fault. Transfo... more Diagnostic goal of transformers in service is to detect the winding or the core in fault. Transformers are valuable equipment which makes a major contribution to the supply security of a power system. Consequently, it is of great importance to disequilibria the three phases courant of power transformers. So, vector diagram Analysis is useful tool for reliable detection of incipient mechanical fault in a transformer, by finding winding or core defects. The authors propose this article, the coupled circuits method, because, it gives most possible exhaustive modelling of transformers. Measurement courant homopolaire in order to improve and simplify the response for à faults transformer.This study can be useful as a base data for the other transformers of the same categories intended for distribution grid. Keywords—Diagnostic; Short-Circuit; Transformer Faults; unbalanced current.
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