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Comparative study of effectiveness of different var compensation devices in large-scale power networks

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Journal of Central South University 2013年第3期20卷 715-723页

作者： Reza Sirjani azah mohamed Hussain Shareef Department of Electrical Electronic and Systems Engineering Universiti KebangsaanBangi 43600Malaysia

A comparison of the effectiveness of installing reactive power compensators,such as shunt capacitors,static var compensators(SVCs),and static synchronous compensators(STATCOMs),was presented in large-scale power networks.A suitable bus was first identified using modal analysis method.The single shunt capacitor,single SVC,and single STATCOM were installed separately on the most critical bus.The effects of the installation of different devices on power loss reduction,voltage profile improvement,and voltage stability margin enhancement were examined and compared for 57-and 118-bus transmission systems.The comparative study results show that SVC,and STATCOM are expensive compared to shunt capacitor,yet the effect of installing STATCOM is better than SVC and the effect of installing SVC is better than that of shunt capacitor in achieving power loss reduction,voltage profile improvement and voltage stability margin enhancement.

关键词：无功补偿装置电力网络 STATCOM 并联电容器电压稳定裕度低功率损耗无功功率补偿静止无功补偿

Identification of voltage sag source location using S and TT transformed disturbance power

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Journal of Central South University 2013年第1期20卷 83-97页

作者： Hussain Shareef azah mohamed Ahmad Asrul Ibrahim Department of Electrical Electronics and Systems EngineeringFaculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia43600 BangiSelangorMalaysia

An alternative method was introduced for voltage sag source location based on S and TT transformed disturbance powers. It is done to avoid the wrong and inconclusive detection of conventional disturbance power method proposed in the literature. Unlike in the case of the traditional method, the proposed method first transforms the recorded voltage and current during the sag event to some special features before calculating the new version of disturbance powers. The effectiveness of the proposed method has been verified through simulation and actual data from an industrial power system. The results show that the presented method can correctly detect the location of voltage sag source.

关键词：电压暂降骚扰功率位置转化识别干扰功率事件记录电力系统

Power swing and voltage collapse identification schemes for correct distance relay operation in power system

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Journal of Central South University 2013年第4期20卷 988-1000页

作者： Ahmad F. Abidin azah mohamed Hussain Shareef Department of Electrical Electronic and Systems Engineering Universiti Kebangsaan Malaysia

The new techniques were presented for preventing undesirable distance relay maloperation during voltage collapse and power swings in transmission grids. Initially, the work focused on the development of a fast detection of voltage collapse and a three-phase fault at transmission lines by using under impedance fault detector (UIFD) and support vector machine (SVM). Likewise, an intelligent approach was developed to discriminate a fault, stable swing and unstable swing, for correct distance relay operation by using the S-transform and the probabilistic neural network (PNN). To illustrate the effectiveness of the proposed techniques, simulations were carried out on the IEEE 39-bus test system using the PSS/E and MATLAB software.

关键词：距离继电器电压崩溃操作电源电力系统 MATLAB软件输电线路故障识别摆幅

A method for real power transfer allocation using multivariable regression analysis

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Journal of Central South University 2012年第1期19卷 179-186页

作者： Hussain Shareef azah mohamed Saifunizam Abd.Khalid Mohd Wazir Mustafa Faculty of Electrical Engineering and Built Environment Universiti Kebangsaan Malaysia43600 BangiMalaysia Faculty of Electrical Engineering Universiti Teknologi Malaysia81310 JohorMalaysia

A multivariable regression(MVR) approach is proposed to identify the real power transfer between generators and 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 determine suitable regression coefficients using MVR model to estimate the power transfer.The 25-bus equivalent system of south Malaysia is utilized as a test system to illustrate the effectiveness of the MVR output compared to that of the MNE method.The error of the estimate of MVR method ranges from 0.001 4 to 0.007 9.Furthermore,when compared to MNE method,MVR method computes generator contribution to loads within 26.40 ms whereas the MNE method takes 360 ms for the calculation of same real power transfer allocation.Therefore,MVR method is more suitable for real time power transfer allocation.

关键词：多元回归分析分配计算权力跨国公司负载流量电机负荷二尖瓣潮流信息

An Assessment of Diffuse Solar Energy Models in Terms of Estimation Accuracy

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An Assessment of Diffuse Solar Energy Models in Terms of Est...

Harmonic Measurement and Analysis during Electric Vehicle Charging

2011 2nd International Conference on Advances in Energy Engineering(ICAEE)

作者： Tamer Khatib azah mohamed Marwan Mahmoud K.Sopian Department of Electrical Electronic & System EngineeringFaculty of Engineering & Built EnvironmentUniversiti Kebangsaan Malaysia Department of Electrical Engineering An-Najah National University Solar Energy Research Institute Universiti Kebangsaan Malaysia

This paper presents models for diffuse solar energy on a horizontal surface for main five sites in Malaysia.The diffuse solar energy is modeled using linear,non-linear and ANN models.Three statistical values are used to evaluate the developed solar energy models,namely,the mean absolute percentage error,MAPE,root mean square error,RMSE and mean bias error,MBE.The results showed that the ANN models are superior compared to the other models in which the MAPE of the ANN model is 1.53%,while the MAPE of the linear and nonlinear models are 4.35%and 3.74%,respectively.The accurate ANN models can therefore be used to predict solar energy in Malaysia and nearby regions.

关键词： Solar energy modeling diffuse solar energy ANN Malaysia

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Engineering（科研） 2013年第1期5卷 215-220页

作者： MohdZamriChe Wanik Mohd FadzilMohd Siam Afida Ayob Subi yanto azah mohamed Abu HanifahAzit Saharuddin Sulaiman mohamed Azrin mohamed Ali Zahrul Faizi Hussein Ahmad Kamil MatHussin Malaysian Green Technology Corporation Bandar BaruBangi Malaysia Power System Research Group UniversitiKebangsaan Malaysia Malaysia TNB Distribution Malaysia Malaysia TNB Research Malaysia Malaysia

This paper presentsand describes harmonic measurement and analysis of studying harmonic propagation during electric vehicle (EV) charging. The measurement study is performed on a golf cart and two modern type of EVs. Harmonics from a single EV charging and a group of EV charging was measured. The voltage and current waveform during the charging was captured and analyzed to investigate the harmonic components that exist in the electrical system. Total current harmonic distortion (THDi) and total voltage harmonic distortion (THDi) were both calculated. Modern electric vehicles are found to release low THDi but higher THDv compared to a golf cart. On the measurement study during charging of? a group of EV, it is found that the summation of THD is not linear with a number of vehicles. The finding of the study reveals that harmonic contamination from EV charging on electrical grid is not as critical as thought by most of power system researchers and engineers.

关键词： Electric Vehicle Total Harmonic Distortion Electric Vehicle Charging Harmonic Power Quality

A novel coordinated control strategy considering power smoothing for a hybrid photovoltaic/battery energy storage system

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Journal of Central South University 2016年第2期23卷 394-404页

作者： DAUD Muhamad Zalani mohamed azah HANNAN M A School of Ocean Engineering Universiti Malaysia Terengganu Department of Electrical Electronicand Systems EngineeringUniversiti Kebangsaan Malaysia

This work presents a novel coordinated control strategy of a hybrid photovoltaic/battery energy storage(PV/BES) system. Different controller operation modes are simulated considering normal, high fluctuation and emergency conditions. When the system is grid-connected, BES regulates the fluctuated power output which ensures smooth net injected power from the PV/BES system. In islanded operation, BES system is transferred to single master operation during which the frequency and voltage of the islanded microgrid are regulated at the desired level. PSCAD/EMTDC simulation validates the proposed method and obtained favorable results on power set-point tracking strategies with very small deviations of net output power compared to the power set-point. The state-of-charge regulation scheme also very effective with SOC has been regulated between 32% and 79% range.

关键词：协调控制策略储能系统 PSCAD/EMTDC 电池光伏混合输出功率 BES

Reliability improvement in distribution systems employing an integrated voltage sag mitigation method using binary gravitational search algorithm

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Journal of Central South University 2013年第11期20卷 3002-3014页

作者： Salman Nesrullah mohamed azah Shareef Hussain Department of Electrical Electronics and Systems EngineeringFaculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia

A method for improving the level of reliability of distribution systems is presented by employing an integrated voltage sag mitigation method that comprises a two-staged strategy,namely,distribution network reconfiguration(DNR)followed by DSTATCOM placement.Initially,an optimal DNR is applied to reduce the propagated voltage sags during the test period.The second stage involves optimal placement of the DSTATCOM to assist the already reconfigured network.The gravitational search algorithm is used in the process of optimal DNR and in placing DSTATCOM.Reliability assessment is performed using the well-known indices.The simulation results show that the proposed method is efficient and feasible for improving the level of system reliability.

关键词：系统可靠性搜索算法缓解方法电压暂降配电系统 DSTATCOM 引力集成

Novel quantum-inspired firefly algorithm for optimal power quality monitor placement

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Frontiers in Energy 2014年第2期8卷 254-260页

作者： Ling Ai WONG Hussain SHAREEF azah mohamed Ahmad Asrul IBRAHIM Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia Bangi 43600 Malaysia

The application of a quantum-inspired firefly algorithm was introduced to obtain optimal power quality monitor placement in a power system. The conventional binary firefly algorithm was modified by using quantum principles to attain a faster convergence rate that can improve system performance and to avoid premature convergence. In the optimization process, a multi-objective function was used with the system observability constraint, which is determined via the topological monitor reach area concept. The multi-objective function comprises three functions： number of required monitors, monitor over-lapping index, and sag severity index. The effectiveness of the proposed method was verified by applying the algorithm to an IEEE 118-bus transmission system and by comparing the algorithm with others of its kind.

关键词： quantum-inspired binary firefly algorithm topological monitor reach area power quality