Papers by Mahmoud khamaira
Proceedings of First Conference for Engineering Sciences and Technology: Vol. 2, 2018
This volume contains contributed articles of Track 4, Track 5 & Track 6, presented in the... more This volume contains contributed articles of Track 4, Track 5 & Track 6, presented in the conference CEST-2018, organized by Faculty of Engineering Garaboulli, and Faculty of Engineering, Al-khoms, Elmergib University (Libya) on 25-27 September 2018. Track 4: Industrial, Structural Technologies and Science Material Track 5: Engineering Systems and Sustainable Development Track 6: Engineering Management Other articles of Track 1, 2 & 3 have been published in volume 1 of the proceedings at this lin
مجلة الجامعة الأسمرية: العلوم التطبيقية
Nowadays, due to the fast growth of electronic devices, harmonic issues have become a main matter... more Nowadays, due to the fast growth of electronic devices, harmonic issues have become a main matter for current day electrical operators. Some of the causes of harmonics are: a) ripples in voltage waveform of machines, b) flux distortion in the synchronous machines, c) transformer magnetizing currents, d) non-linear loads such as static power converters, arc furnaces, and e) static-var compensators as suppliers of continuously variable var sources. The harmonic filtering is one of the solutions for preventing the worrying harmonics from entering the rest of the system. There are basically two types of filters: i) passive, where the filter components are passive elements such as resistor, inductor, and capacitor, and ii) active, where the filter has a controlled current or voltage source. This peper introduces a single-tuned passive filter to minimize the harmonic distortion of AL-TAHRER substation (30KV). The offered filter and studied system modeling are built by ETAP software. Resul...
Electrical load forecasting is a method of guessing the future of the electricity demand. Load fo... more Electrical load forecasting is a method of guessing the future of the electricity demand. Load forecast is an essential factor for power system planners and demand controllers. This is to ensure that would be an adequate amount of the electricity meeting the increasing demands. Therefore, an accurate load forecasting model can effectively lead to reduction of power system cost, better budget planning, and maintenance scheduling. The future load on a power system is predicted by extrapolating a predetermined relationship between the load and its influential variables. Determination of this relationship involves modeling and estimation the coefficient of the model through the use of an efficient parameter estimation technique. This paper presents a short term forecasting model for Libyan electric network using multi parameter regression method. The proposed method shows a result with small deviation between the actual and expected load, which means Multi parameter regression emerged a...
Proceedings of First Conference for Engineering Sciences and Technology: Vol. 1, 2018
Long term load demand forecasting is a necessary process in electric power system operation and d... more Long term load demand forecasting is a necessary process in electric power system operation and development. It contains the accurate prediction of both magnitudes and geographical locations of electric load over the different periods of the planning horizon. Several economic implications of power utility such as economic scheduling of generating capacity, scheduling of fuel purchases, security analysis, planning of power development, maintenance scheduling and dispatching of generation units are mainly worked based on accurate load forecasting. In this paper, the peak load for seven years ahead is performed for the Libyan electric network with the simple regression method. MATLAB programming has been used for computational work. The results attained are validated with the real data obtained from the National Control Center of the General Electricity Company of Libya (GECOL).
Proceedings of First Conference for Engineering Sciences and Technology: Vol. 1, 2018
This paper investigates the electrical performance of outdoor porcelain and glass insulators when... more This paper investigates the electrical performance of outdoor porcelain and glass insulators when subjected to an 11 kV AC voltage. The insulators are modeled in two dimensions, and the analysis of COMSOL software is used for the finite element simulations. The electric field and voltage distribution in the vicinity of the insulator surfaces were computed and examined. Comparative studies of field and equipotential lines for the insulators are presented under both dry clean and wet polluted conditions. The pollution layer over the insulator surfaces are assumed to be uniform with 0.5 mm thickness. The simulation results show that the field distribution of porcelain and glass insulators were obviously depended on the contamination conditions. The critical of high field regions on both surfaces were identified and the effect of the pollution on the electric field distribution was revealed. The results also confirmed that porcelain insulator has slightly higher field distribution near the high voltage end compared with the glass surface.
I praise and glorify the name of Allah the Almighty who has always protected, sustained and helpe... more I praise and glorify the name of Allah the Almighty who has always protected, sustained and helped me, and my family, and also created pleasant opportunities for me to capitalise on. I would like to express my deepest gratitude to my supervisor Dr. Ahmed Abu-Siada for this invaluable support and excellent supervision during my PhD study at Curtin University. Also, many thanks for my core supervisor Professor Syed Islam. I would also like to sincerely thank all the staff of the Electrical and Computer Engineering department for their support. I would like to acknowledge the support of all my PhD's colleagues. Thank you for the fruitful discussions and friendships, which made my academic life easy and enjoyable. Many thanks to my Libyan friends, who made my stay in Perth stress-free while I was far away from my family. Last but not the least; I would like to thank my respected and beloved mother and father for their unconditional love and prayers for me. Heart felt grateful to my beloved wife for her encouragement, invaluable support, and her patience while looking after our daughter alone in my absence.
2015 IEEE 24th International Symposium on Industrial Electronics (ISIE), 2015
Frequency response analysis (FRA) has been employed as an effective tool for the detection of var... more Frequency response analysis (FRA) has been employed as an effective tool for the detection of various mechanical winding and core deformations within electrical power transformer. Traditional FRA signature interpretation relies on the magnitude of the FRA plot although all practical frequency response analyzers are able to provide both magnitude and angle of the FRA signal in wide frequency range. Moreover, no attention has been given to the impact of power transformer insulating oil degradation on the FRA signature. This paper presents is aimed at introducing a new interpretation approach of the FRA signature using polar plot which is obtained by incorporating FRA signature magnitude and phase into one plot. The paper also investigates the impact of insulating mineral oil degradation on the proposed polar plot signature. Digital image processing (DIP) technique is developed to automate the interpretation process. In this regard, the physical geometrical dimension of a single-phase transformer filled with insulating mineral oil is simulated using three-dimensional finite element analysis to emulate real transformer operation. FRA polar plot signatures are measured and analyzed for various health conditions of the mineral oil. Results show that insulating mineral oil degradation has an impact on the transformer FRA polar plot signature. The proposed FRA polar plot technique is easy to implement within any frequency response analyzer.
2015 IEEE Power & Energy Society General Meeting, 2015
Doubly Fed Induction Generators (DFIGs) are currently extensively used in variable speed wind pow... more Doubly Fed Induction Generators (DFIGs) are currently extensively used in variable speed wind power plants due to their superior advantages that include reduced converter rating, low cost, reduced losses, easy implementation of power factor correction schemes, variable speed operation and four quadrants active and reactive power control capabilities. On the other hand, DFIG sensitivity to grid disturbances, especially for voltage sags represents the main disadvantage of the equipment. In this paper, a coil is proposed to be integrated within the DFIG converters to improve the overall performance of a DFIG-based wind energy conversion system (WECS). The charging and discharging of the coil are controlled by controlling the duty cycle of the switches of the dc-dc chopper. Simulation results reveal the effectiveness of the proposed topology in improving the overall performance of the WECS system under study.
Australian Journal of Electrical and Electronics Engineering
2014 Australasian Universities Power Engineering Conference (AUPEC), 2014
2014 IEEE PES General Meeting | Conference & Exposition, 2014
ABSTRACT Doubly Fed Induction Generators (DFIGs) are nowadays extensively used in variable speed ... more ABSTRACT Doubly Fed Induction Generators (DFIGs) are nowadays extensively used in variable speed wind power plants due to their advantages that include reduced converter rating, low cost, reduced losses with an improved efficiency, easy implementation of power factor correction schemes, variable speed operation and four quadrants active and reactive power control capabilities. On the other hand, DFIG sensitivity to grid disturbances, especially for the voltage dip represents the main disadvantage of the equipment. This paper presents the application of superconducting magnetic energy storage (SMES) unit to improve the overall performance of a DFIG-based wind energy conversion systems (WECS). Two control approaches namely; hysteresis current controller (HCC) along with proportional integral (PI) controller and a fuzzy logic (FL) controller for the SMES unit are presented and compared. Various grid codes are used to examine the capability of the two proposed controllers to improve the low voltage ride through (LVRT) capability of the DFIG to maintain the wind turbine connection to the grid through fault durations.
2014 Australasian Universities Power Engineering Conference (AUPEC), 2014
2013 Australasian Universities Power Engineering Conference (AUPEC), 2013
Doubly Fed Induction Generators (DFIGs) are widely used in variable speed wind turbine owing to i... more Doubly Fed Induction Generators (DFIGs) are widely used in variable speed wind turbine owing to its superior advantages that include ability to extract more energy from turbine, capability to control active and reactive power independently and the usage of reduced converter rating that reduces its overall cost. The application of DFIG in large wind energy conversion systems (WECS) has reached 55% of the worldwide total wind capacity during the year 2012. On the other side fluctuating output power, weak fault ride through capability and high sensitivity to grid disturbances are the main issues that affect DFIG performance. In this paper, superconducting magnetic energy storage (SMES) unit is proposed to improve the overall performance of a DFIG-based WECS during voltage sag disturbance in the grid side. A new control approach for SMES unit using hysteresis current controller (HCC) along with proportional integral (PI) controller is introduced. Simulations results reveal the effectiveness of the proposed SMES controller in improving the overall performance of the WECS system under study.
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Papers by Mahmoud khamaira