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A Test for Solid Phase Extracted Polychlorinated Biphenyls (PCBs) Levels in Transformer Oil
E. A. Kamba,
A. U. Itodo,
E. Ogah
Issue:
Volume 2, Issue 3, May 2013
Pages:
57-65
Received:
5 April 2013
Published:
30 May 2013
Abstract: Polychlorinated biphenyls (PCBs), the synthetic electrical insulation fluid in transformers and capacitors, known to reduce the risk of fire hazards due to their high chemical stability and low flammability turned out to be environmentally hazardous. In this research, different techniques used to analyses Polychlorinated biphenyls (PCBs) in transformer oil including their qualification and identification processes have been outlined. 12 samples of transformer oils collected from various transformers from Kebbi state, Nigeria were investigated. Solid Phase Extraction (SPE) method was used to treat the oil samples and extracts were analyzed on Gas Chromatography with Electron Capture Detection (GC/ECD). No detectable PCBs were observed. To check the efficiency the SPE tubes, oil sample A10 was spiked with Mix 525 of PCB standard and treated. A full recovery of all the PCBs of Mix 525 was made even at a level as low as 50ng/ul with GC/MS. The results obtained in this study confirm that transformer oil from Kebbi state is well within the safe level of PCBs in accordance with EPA PCB Regulatory limited.
Abstract: Polychlorinated biphenyls (PCBs), the synthetic electrical insulation fluid in transformers and capacitors, known to reduce the risk of fire hazards due to their high chemical stability and low flammability turned out to be environmentally hazardous. In this research, different techniques used to analyses Polychlorinated biphenyls (PCBs) in transfo...
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Compensation of Voltage Flicker by Using Facts Devices
Jyothilal Nayak Bharothu,
K Lalitha
Issue:
Volume 2, Issue 3, May 2013
Pages:
66-80
Received:
24 April 2013
Published:
30 May 2013
Abstract: Voltage flicker occurs when heavy loads are periodically turned on and off in a weak distribution system. If the distribution system’s short circuit capacity is not large enough, voltage fluctuations will occur. Voltage flickering can be extremely harmful to sensitive electronic equipment. Computerized equipment requires stable voltage to perform properly. This paper covers the contrasting approaches; dealing with the voltage flicker mitigation in three stages and assessing the related results in details. Initially, the voltage flicker mitigation, using FCTCR (Fixed Capacitor Thyristor Controlled Reactor), was simulated. Secondly, the compensation for the Static Synchronous Compensator (STATCOM) has been performed. In this case, injection of harmonics into the system caused some problems which were later overcome by using 12-pulse assignment of SATCOM and RLC filters. The obtained results show that STATCOM is very efficient and effective for the flicker compensation. All the simulations have been performed on the MATLAB Software
Abstract: Voltage flicker occurs when heavy loads are periodically turned on and off in a weak distribution system. If the distribution system’s short circuit capacity is not large enough, voltage fluctuations will occur. Voltage flickering can be extremely harmful to sensitive electronic equipment. Computerized equipment requires stable voltage to perform p...
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Alleviation of Harmonics for the Self Excited Induction Generator (SEIG) Using Shunt Active Power Filter
A. M Bouzid,
A. Cheriti,
M. Bouhamida,
M. Benghanem
Issue:
Volume 2, Issue 3, May 2013
Pages:
81-87
Received:
15 May 2013
Published:
10 June 2013
Abstract: The Self Excited Induction Generator (SEIG) is an isolated power source, whose terminal voltage and frequency are controlled by the excitation of capacitance or the load impedance. A new strategy based on an active power filter (APF) for controlling the current and power quality of the self-excited induction generator (SEIG) is also presented in this paper. The proposed active filter proved to play an important role and give good dynamic response and robust behavior upon changes in load parameters. This investigation demonstrated that power average control strategy can facilitate the improvement of the power quality. This control method extracts fundamental (reference) components of the source current for the shunt active power line conditioners for nonlinear loads and unbalanced loads. The shunt APF in conjunction with the proposed controller perform perfectly under different steady state and transient conditions. The simulation results with nonlinear loads and unbalanced loads have showed the effectiveness of the proposed scheme for harmonic reduction in Wind based Power Generation.
Abstract: The Self Excited Induction Generator (SEIG) is an isolated power source, whose terminal voltage and frequency are controlled by the excitation of capacitance or the load impedance. A new strategy based on an active power filter (APF) for controlling the current and power quality of the self-excited induction generator (SEIG) is also presented in th...
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Simulation of Non Linear Adaptive Observer for Sensorless Induction Motor Control
Benheniche Abdelhak,
Bensaker Bachir
Issue:
Volume 2, Issue 3, May 2013
Pages:
88-93
Received:
20 May 2013
Published:
30 June 2013
Abstract: This paper presents a model reference adaptive system based sensorless induction motor drive. In this scheme, an adaptive full order flux observer is used. The simulation result show that with the large PI gain for the adaptive scheme, the convergence for the speed estimation is fast and very well, however higher harmonics and noises are included in the estimated speed. Usually noises caused by inverter. Simulation results show that proposed scheme can estimate the motor speed under various adaptive PI gains and estimated speed can replace to measured speed in sensorless induction motor.
Abstract: This paper presents a model reference adaptive system based sensorless induction motor drive. In this scheme, an adaptive full order flux observer is used. The simulation result show that with the large PI gain for the adaptive scheme, the convergence for the speed estimation is fast and very well, however higher harmonics and noises are included i...
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Designing of Dynamic Voltage Restorer (DVR) to Improve the Power Quality for Restructured Power Systems
M. Kavitha,
T. Chandrasekhar,
D. Mohan Reddy
Issue:
Volume 2, Issue 3, May 2013
Pages:
94-97
Received:
29 May 2013
Published:
30 June 2013
Abstract: In Restructured power systems, Power quality is one of the major concerns in the present era. The problem of harmonics, voltage sags and swells and its major impact on sensitive loads are well known. To solve this problem, custom power devices are used. One of those devices is the Dynamic Voltage Restorer (DVR), which is one of the most efficient and effective modern custom power devices used in power distribution networks for the power quality improvement. Control of power quality problems involves cooperation between network operator (utility), customer and equipment manufacturer. A Dynamic Voltage Restorer (DVR) is a distribution voltage DC-to-AC solid-state switching converter that injects three single phase AC output voltages in series with the distribution feeder and in synchronism with the voltages of the distribution system. A DVR is interface equipment between utility and customer connected in series between the supply and load to mitigate the three major power quality problems, namely the harmonics, voltage sags, and swells etc. This paper concentrates on the designing of Dynamic Voltage Restorer (DVR) for the harmonics compensation so that it can improve the Power Quality (PQ).
Abstract: In Restructured power systems, Power quality is one of the major concerns in the present era. The problem of harmonics, voltage sags and swells and its major impact on sensitive loads are well known. To solve this problem, custom power devices are used. One of those devices is the Dynamic Voltage Restorer (DVR), which is one of the most efficient a...
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