Hala Abdelmegeed

National Institute of Standards (Egypt) | NIS · High Voltage

This study optimizes and evaluates a Photovoltaic-Wind-Battery/Electric Vehicle Charging Station (PVWB/ EVCS) system using four Multi-Objective Optimization (MOO) techniques: MOPSO, NSGAII, NSGAIII, and MOEA/D. The main goals are to minimize the Total Net Present Cost (TNPC) and Loss of Power Supply Probability (LPSP) of the system, which are cruci...

One of the crucial assessments for electricity meters involves the solar radiation test, typically conducted using solar simulators. This work focuses on the modification of the climatic chamber (MKF-240) at the Egyptian National Institute of Standards (NIS) to serve as a solar simulator. To replicate solar test conditions, enhancements such as an...

Actin, a highly conserved protein, plays a dominant role in Non-small cell lung cancer (NSCLC). Late diagnosis and the aggressive nature of NSCLC pose a significant threat. Studying the clinic pathological properties of NSCLC proteins is a potential alternative for developing treatment strategies. Towards this, 35 downregulated actin cytoskeletal p...

In its broadest sense, the particular topology of radial distribution networks (RDNs), high resistance-to-reactance (R/X) ratios, the misuse and exploitation of these systems, specifically with increased variable renewable energy sources (VRESs) that are added in these networks, increased load demands, and nontechnical losses are leading to a signi...

The spread of power electronics-based non-linear loads increase the harmonics distortion level in power systems. Real-time interactive systems are considered the most promising solution to several grid power quality problems. The practical design considerations are the aim of this study. A current sensor in addition to controller circuits is used f...

Sustaining a stable level of power quality in the localized network is a growing challenge due to the increased use of power electronics. This paper proposes a novel interactive technique that reads the load current according to the connected loads. Whenever equipment is started running, the system is immediately read the distorted current for thre...

Electricity meters are devices that record the electrical energy consumed by the customer. Recently, the electricity meter has developed as a result of technological progress, and it transformed from an electro-mechanical energy meter to become an electronic meter. The electronic energy meter consists of electronic components which may change its p...

In the electrical power industry, high current measurements have a fundamental importance. This necessitates the use of highly accurate, precise, and traceable techniques to calibrate measuring instruments in order to preserve the output quality. High current measuring techniques are being developed continuously to improve measurement accuracy and...

Main text AFRIMETS.EM-S1 supplementary comparison on resistance standards at 1 Ω, 10 Ω, 100 Ω, 1 kΩ and 10 kΩ commenced November 2015 and ended June 2018. The comparison approved by AFRIMETS technical committee for Electricity and Magnetism (TC-EM) and Consultative Committee for Electricity and Magnetism (CCEM). Seven National Metrology Institutes...

In this paper, new traceable measurement systems for automatic calibration of high current sources have been established at the National Institute of Standards (NIS), Egypt. These systems can be used in laboratories mainly depending on calibrators with current coils, in case of unavailability of current transformers. Traceability of high current ha...

Improved Fractional Order Darwinian Particle Swarm Optimization (FODPSO) has been proposed to identify the parameters of solar PV cells and modules. For this purpose, the traditional PSO algorithm has been adapted and an improved one using the fractional order calculus has been especially designed as well. The proposed FODPSO together with the PSO...

This paper presents an integrated method to identify the fault direction in the presence of a series compensator via also identifying the power flow direction. The presented method relies on monitoring both measured angle of the positive-sequence (PS) currents and magnitude of PS voltage. The change of PS voltage magnitude is used to detect the cur...

Particle Swarm Optimization technique has been improved by fractional order calculus to be used for photovoltaic (PV) modeling. The modified technique which is called Fractional Order Darwinian Particle Swarm Optimization (FODPSO) has been constructed to estimate the optimal electrical parameters of PV modules. Single and double diode models have b...

In this article, we propose a fault directional identification scheme that depends on the positive-sequence components of current based on an investigation of pre-fault and fault phase angles. The proposed protection scheme is developed for both distribution and transmission systems. However, as the current-only approach depends on the pre-fault cu...

A 20-year-old male is presented with hemoptysis since 3 months. Plain chest X-ray and computed tomography (CT) chest at that time showed bilateral hilar shadows. Recent X-ray showed a huge right-sided well-defined opacity. CT chest and magnetic resonance angiography were ordered for him revealing a huge intrapulmonary hematoma. q

This paper presents an efficient load flow (LF) technique that exhibits an improved convergence characteristic to be employed in balanced radial distribution systems (RDSs) having voltage dependent loads (VDLs). The key enabler of this approach is the construction of load injection to bus voltage (LIBV) matrix that is utilized to carry out the back...

The current study presents a modified sine cosine optimization (MSCO) algorithm for solving the non-smooth environmental/economic power dispatch problem. In the proposed MSCO algorithm, random search agents’ population is initialized in the search domain for simultaneous optimization of both the combined economic and environmental objectives. Added...

National Institute of Standards is the National Metrology Institute of Egypt, which realizes units of measurements according to the Inter-na-tional System of Units. The DC Josephson Voltage Standard is used as a primary standard to reproduce the unit of volt and provide tracea-bility of measurements to the SI units. JVS, Zener diode reference stand...

This paper describes in details a commercial green building that has been designed and constructed in Marsa Matrouh, Egypt. The balance between homebuilding and the sustainable environment has been taken into consideration in the design and construction of this building. The building consists of one floor with 3 m height and 2810 m2 area while the...

Energy is one of the most important categories in the Green Building Rating Systems all over the world. Green Building is a building that meets the energy requirements of the present with low energy consumption and investment costs without infringing on the rights of forthcoming generations to find their own needs. Despite having more than a qualif...

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the National Institute for Standards (NIS), Giza, Egypt, was carried out from August to September 2014. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_B (ZB) and BIPM_C (ZC), were transport...

This paper discusses enhancing of the measurements’ uncertainty for AC high voltage up to 100 kV. This is achieved by using a high voltage divider calibration method. Voltage measurements have been carried out at the Egyptian national institute for standards (NIS), using a high voltage measuring system (Phenix-KVM100), that consists of a high volta...

This paper introduces a new methodology for obtaining high voltage DC measurements traceability to the International System of Units (SI) at the Egyptian National Institute for Standards (NIS). The traceability has been achieved via the NIS automated 10 V DC Josephson Voltage Standard (JVS). A 100 kV DC voltage divider with a nominal voltage ratio...

AC high voltage measurements traceability up to 100 kV has been achieved at the National Institute for Standards (NIS), Egypt. The Phenix High Voltage divider (KVM100) with a full range of 100 kV AC is being used with its display in parallel with a high sensitive digital voltmeter. The traceability has been realized by calibrating this digital volt...

The series connection effect on the electrical performance of a large area multicrystalline Silicon solar cell (21 cm × 21 cm) with back contact technology has been considered in a desert area. Short circuit current, open circuit voltage and output power are the major electrical parameters normally characterise the solar cells.The current shunt mea...

The paper describes an interlaboratory comparison program between the National Institute for Standards (NIS), Egypt and the Istituto Nazionale di Ricerca Metrological (I.N.Ri.M.), Italy for measuring low ac voltages. The aim of this program is to demonstrate the technical competence of both institutes. The interlaboratory comparison has been carrie...

This paper introduces a new tool for fault detection in high voltage electrical networks; the new tool can be used by high speed digital relays to detect fault presence besides selecting the faulted phase(s). The suggested tool uses a new technique that squares both of the instantaneous voltage signal and its complement to produce a unity relation...

The electrical International System of Units (SI) are defined and realized as DC electrical quantities. National Institute for Standards (NIS), Egypt maintains the DC voltage unit by using the DC Josephson Voltage Standard (JVS) as a primary standard for DC voltage adding to eight zener diode reference standards as DC voltage secondary standards. T...

The electrical performance of a module consisting of four identical large area multicrystalline silicon solar cell units connected in series has been studied in a desert area under ambient conditions. Each cell is of area 21cm×21cm with back contact technology where the current collected by the fine finger grid is led to the back side through 25 ho...

Automation in measurements has extreme range of metrology applications which include instruments controlling, measurement processing and results analysing. As, commercial software is not suitable for the highly accurate metrological laboratories, the construction of an appropriate software is one of the priorities for these laboratories; consequent...

Automation in measurement has wide range of electrical metrology applications and construction of powerful calibration software is one of the highly accurate metrological laboratories' priorities. Thus, two automatic systems for controlling and calibrating the electrical reference standards have been established at National Institute for Standards...

A new automatic system for calibrating the solid state DC voltage reference standards (Zener Diode reference standards) has been established at National Institute for Standards (NIS), Egypt to disseminate the unit of volt in the country. Besides, this system has been implemented as a coherent structure that, from the national DC voltage reference s...

In this paper, a new technique using a Current Shunt and a Micropotentiometer has been used to study the electrical performance of a large area multicrystalline silicon solar cell at outdoor conditions. The electrical performance is mainly described by measuring both cell short circuit current and open circuit voltage. The measurements of this cell...

This paper describes in details a new design of a fully automated multiple output micropotentiometer (pot). A prototype has been built at the National Institute for Standards (NIS), Egypt to establish this highly im-proved AC voltage source in the millivolt range. The new device offers three different outputs covering a wide frequency range from o...

The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shunt measuring technique. Therefore, most of the problems encountered with traditional measuring techniques are avoided. The temperature...

The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shunt measuring technique. Therefore, most of the problems encountered with traditional measuring techniques are avoided. The temperature...

This paper describes in detail a new concept in measuring and calibrating the electrical parameters of a large area multicrystalline silicon solar cell of 21cm × 21cm with back contact technology. The solar cell electrical performance in the outdoor is mainly described by measuring both short circuit current and open circuit voltage. Traditional me...

Comparison Of The Technical Performance For Different Design Of Single Junction Thermal Converters

This paper describes the technical procedures for establishment and characterization of a traceable AC voltage source at National Institute for Standards (NIS), Egypt. This accurate device was established to cover ranges from 10 mV to 500 mV at frequencies up to 20 kHz. The device was entirely implemented in NIS as a part of upgrading process for t...

The technical characteristics of four different designs of single junction thermal converters (SJTCs) are evaluated in this paper. This variety in the designs represents the technical trials in developing enhanced thermoelements and in minimizing the values of their transfer errors. A traceable automated system was used to investigate the time resp...

A 20-year-old male is presented with hemoptysis since 3 months. Plain chest X-ray and computed tomography (CT) chest at that time showed bilateral hilar shadows. Recent X-ray showed a huge right-sided well-defined opacity. CT chest and magnetic resonance angiography were ordered for him revealing a huge intrapulmonary hematoma. q 2003 Elsevier B.V....