Oalib search

标题关键字摘要作者全部

显示搜索

我的图书馆

OALib Journal期刊

ISSN: 2333-9721

费用：99美元

投稿

时间不限

( 2673 )

( 2024 )

( 2023 )

( 2022 )

自定义范围…

匹配条件： “Mohd. Wazir Mustafa” ，找到相关结果约9777条。
列表显示的所有文章，均可免费获取

第1页/共9777条

每页显示条

Unbundling Generators’ Reactive Power Output in a Competitive Market by Using Graph and Circuit Theory
Mohd. Wazir Mustafa,Hussain Shareef
Elektrika : Journal of Electrical Engineering , 2007,

Abstract: This paper suggests a new method to allocate reactive power output of individual reactive power sources to system loads by tracing the current flow. Based on solved load flow and the network parameters, the method converts power injections and line flows into real and imaginary current injections and flows. These currents are then represented independently as real and imaginary current networks. Since current networks are acyclic lossless networks, proportional sharing principle and graph theory is used to trace the relationship between current sources and current sinks. The contributions from each current source are finally translated into reactive power contributions. The IEEE 14-bus system is used to illustrate the effectiveness of the method. Comparison of the results with previous methods is also given

保存相关文章

Mathematical Model and Stability Analysis of Inverter-Based Distributed Generator
Alireza Khadem Abbasi,Mohd Wazir Mustafa
Mathematical Problems in Engineering , 2013, DOI: 10.1155/2013/195038

Abstract:

保存相关文章

Optimal Placement of Static VAR Compensator Using Genetic Algorithms
Mohd Wazir Mustafa,Wong Yan Chiew
Elektrika : Journal of Electrical Engineering , 2008,

Abstract: The management of power systems has become more difficult than earlier because power systems are operatedcloser to security limits, environmental constraints restrict the expansion of transmission network and the need for longdistance power transfers has increased. The loading of a transmission network can be increased by maintaining propervoltage profile through injecting appropriate reactive power into the system. The existence of the multiple solutions in theoptimal placement of reactive power in the power system typically often get stuck at the local optimum rather than at theglobal optimum. Genetic Algorithms (GAs) are stochastic searching algorithms that make the searching process jumpsrandomly from point to point, thus allowing escape from the local optimum, and search for many sub-optimum points inparallel. This paper presents an evolutionary computation algorithm for enhancing voltage stability. GAs will determine themost vulnerable bus in the power system, where the Static VAR Compensator (SVC) is needed to be installed at that bus aswell as considering installation cost of SVC. The developed algorithms have successfully obtained the best solution foroptimal placement of SVC in the IEEE 9 buses system and TNB northern area 275kV 14-bus system.

保存相关文章

An ANFIS Approach for Real Power Transfer Allocation
Hussain Shareef,Saifulnizam Abd Khalid,Mohd Wazir Mustafa,Azhar Khairuddin
Journal of Applied Mathematics , 2011, DOI: 10.1155/2011/414258

Abstract: This paper proposes an adaptive neurofuzzy interface system (ANFIS) approach to identify the real power transfer between generators. Based on solved load flow results, it first uses modified nodal equation method (MNE) to determine real power contribution from each generator to loads. Then the results of MNE method and load flow information are utilized to train the designed ANFIS. It also incorporated an enhanced feature extraction method called principle component analysis (PCA) to reduce the input features to the ANFIS. The 25-bus equivalent system of south Malaysia is utilized as a test system to illustrate the effectiveness of the ANFIS output compared to that of the MNE method. The ANFIS output provides promising results in terms of accuracy and computation time. Furthermore, it can be concluded that the ANFIS with enhanced feature extraction method reduces the time taken to train the ANFIS without affecting the accuracy of the results.

保存相关文章

Preference Comparison of AI Power Tracing Techniques for Deregulated Power Markets
Hussain Shareef,Saifunizam Abd. Khalid,Mohd Wazir Mustafa,Azhar Khairuddin
Advances in Artificial Intelligence , 2012, DOI: 10.1155/2012/720463

Abstract:

保存相关文章

Abstract: This paper compares the two preference artificial intelligent (AI) techniques, namely, artificial neural network (ANN) and genetic algorithm optimized least square support vector machine (GA-LSSVM) approach, to allocate the real power output of individual generators to system loads. Based on solved load flow results, it first uses modified nodal equation method (MNE) to determine real power contribution from each generator to loads. Then the results of MNE method and load flow information are utilized to estimate the power transfer using AI techniques. The 25-bus equivalent system of south Malaysia is utilized as a test system to illustrate the effectiveness of the AI techniques compared to those of the MNE method. The AI methods provide the results in a faster and convenient manner with very good accuracy. 1. Introduction Nowadays, the electric power industry is under deregulation in response to changes in jurisdiction, technology, market, and competition. Regardless of market environment, it is essential to know whether or not, and to what extent, each power system user contributes to the usage of particular system components. This information facilitates the restructured power system to operate economically and efficiently [1]. Moreover, it brings fair pricing and open access to all system users. Because of nonlinear nature of power flow, it is difficult to determine transmission usage accurately. Therefore, it requires using approximate models, tracing algorithms, or sensitivity indices for usage allocation. Methods based on the -bus or -bus system matrices have recently received great attention since these methods can integrate the network characteristics and circuit theories into line usage and loss allocation. The method reported in [2] is based on Kirchhoff’s current law (KCL), equivalent linear circuit that reaches all lines and loads. Based on the stated assumptions, a recursive procedure was used to construct the equivalent circuit for each bus. Moreover, superposition theorem was applied to the bus’s equivalent circuit starting from a bus whose injected currents were known. Another circuit concept method was proposed by Chang and Lu [3]. It was based on the system -bus matrix and -bus modification. Starting from the load flow solution, branch current is determined as a function of generators’ injected current by using information from the bus impedance matrix. Similarly, contribution to bus voltages was computed as a function of each generator current injection by decomposing the network into different networks. Using the computed voltages

保存相关文章

An Improved Walsh Function Algorithm for Use in Sinusoidal and Nonsinusoidal Power Components Measurement
Saifulnizam Bin Abdul Khalid,Garba Aliyu,Mohd Wazir Mustafa,Hussein Shareef
Journal of Energy , 2013, DOI: 10.1155/2013/807639

Abstract: This paper presents an improved Walsh function IWF algorithms as an alternative approach for active and reactive powers measurement in linear and nonlinear, balanced and unbalanced sinusoidal three-phase load system. It takes advantage of Walsh function unified approach, simple algorithm and its intrinsic high level of accuracy as a result of coefficient characteristics and energy behaviour representation. The developed algorithm was modeled on the Matlab Simulink software; different types of load, linear and nonlinear, were also modeled based on practical voltage and current waveforms and tested with the proposed improved Walsh algorithms. The IEEE standard 1459–2000 which is based on fast Fourier transform FFT approach was used as benchmark for the linear load system. The data obtained from laboratory experiment to determine power components in harmonic load systems using Fluke 435 power quality analyzer PQA which complies with IEC/EN61010-1-2001 standard was modeled and used to validate the improved algorithm for nonlinear load measurement. The results showed that the algorithm has the potential to effectively measure three-phase power components under different load conditions. 1. Introduction The awareness of the problems associated with nonlinear devices and their effects on power components measurement algorithms has considerably increased. The use of these power electronics equipment and appliances with microprocessors has been shown to contribute to the distortion of the voltage and current waveforms of the supply system at the distribution end [1]. This distortion affects the smooth operation of most algorithms use for power components measurement and invariably has negative effect on the quality of the power supply system. Accurate measurement and evaluation of energy consumption are of utmost importance for effective planning, billing, monitoring, maintenance, and further development of the electricity supply system. The deregulation of the power sector has led electricity operators to seek for ways to make the best use of the supply systems. Proper evaluation of the energy consumption is one of the important tasks in electric power industries, especially in electric bill and the electrical energy quality estimation and control [2, 3]. Therefore, several companies are into design and manufacture of energy meters using different algorithms to meet the increasing demand of smart metering [4]. In the pricing of electric bill based on the value of the integral of the load active power measured using kilowatt-hour meter, the electric utility

保存相关文章

Comparative Evaluation of the Antidiabetic Effects of Different Parts of Cassia fistula Linn, a Southeast Asian Plant
John Wilking Einstein,Mustafa Mohd Rais,Mustafa Ali Mohd
Journal of Chemistry , 2013, DOI: 10.1155/2013/714063

Abstract:

保存相关文章

The Silver-Meal Heuristic Method for Deterministic Time-Varying Demand
Mohd Omar,Mustafa Mat Deris
Matematika , 2001,

Abstract: Heuristic policies for time-varying deterministic processes with infinite input rate have been thoroughly explored in the literature. This paper addresses heuristic decision rules for the situation of a deterministic linearly increasing and decreasing demand patterns with a finite input rate. We determine the timing and sizing of replenishment so as to keep the total relevant cost as low as possible. We extended the Silver-Meal heuristic method and found the penalty cost is very low.

保存相关文章

Integrated Help
Khurram Mustafa,Mohd Javed Khan
Asian Journal of Education and e-Learning , 2018, DOI: 10.24203/ajeel.v6i4.5457

Abstract: Teaching computer programming to novice programmers is a challenging job. One possible reason for this is that novice programmers struggle to understand internal manipulation of key programming concepts which causes misconception and difficulties. An observation study was conducted to investigate misconceptions and difficulty experienced by Novice Programmers. Study revealed three major findings - firstly, novice programmers found textual presentation of programming concept to be monotonous; they preferred alternative presentation in the form of – text, audio, video, animation, simulation etc. Secondly, Ergonomics of learning interface causes eye fatigue. Thirdly, to remove misconception when novice programmers search WWW due to numerous search results they suffer from ‘lost-in-hyperspace’ problem.Further, exhaustive survey on existing integrated programming IDE (C, C++, Java Editor, .net Editor, SQL Server, Oracle) revealed integrated help provided by majority of them, suffers from key findings of observational study. To address this, “Integrated Help” content presentation model is proposed. A series of studies established this model to be potentially effective. Learning material facilitated through “Integrated Help” was found to interesting and engaging. As a result it proved to be an aid to novice programmers to develop better understanding of key concepts.

保存相关文章

第1页/共9777条

每页显示条