Mehrshad Salmasi; Homayoun Mahdavi-Nasab
Volume 8, Issue 4 , November 2014, Pages 1-7
Abstract
Active noise control (ANC) works on the principle of destructive interference between the primary disturbance field heard as undesired noise and secondary field which is generated from control actuators. In the simplest system, the disturbance field can be a simple sine wave, and the secondary field ...
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Active noise control (ANC) works on the principle of destructive interference between the primary disturbance field heard as undesired noise and secondary field which is generated from control actuators. In the simplest system, the disturbance field can be a simple sine wave, and the secondary field is the same sine wave but 180 degrees out of phase. This research presents an investigation on the use of different types of neural networks in active noise control. Performance of the multilayer perceptron (MLP), Elman and generalized regression neural networks (GRNN) in active cancellation of acoustic noise signals is investigated and compared in this paper. Acoustic noise signals are selected from a SPIB database. In order to compare the networks appropriately, similar structures and similar training and test samples are deduced for neural networks. The simulation results show that MLP, GRNN, and Elman neural networks present proper performance in active cancellation of acoustic noise. It is concluded that Elman and MLP neural networks have better performance than GRNN in noise attenuation. It is demonstrated that designed ANC system achieve good noise reduction in low frequencies.
Mahmood Seifouri; Saeed Olyaee; Moslem Dekamin
Volume 8, Issue 4 , November 2014, Pages 9-15
Abstract
In this paper, we report a new design of As2Se3 chalcogenide glass photonic crystal fiber (PCF) with ultra-flattened dispersion at mid-infrared wavelength range. We have used the plane wave expansion method (PWE) for designing the structure of As2Se3 glass PCF at different wavelength windows. In ...
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In this paper, we report a new design of As2Se3 chalcogenide glass photonic crystal fiber (PCF) with ultra-flattened dispersion at mid-infrared wavelength range. We have used the plane wave expansion method (PWE) for designing the structure of As2Se3 glass PCF at different wavelength windows. In the proposed structure with hole to hole spacing and , the negative dispersion is -1025 ps/nm/km at the wavelength of 1.55µm and also an ultra-flattened dispersion is achieved at the wavelength range of 3.5-18μm. Hence such PCFs have a high potential to be used as dispersion compensating fibers at 1.55µm wavelength in optical communication systems. The ultra-flattened dispersion at the wavelength range of 3.5-18μm can be employed to achieve high power supercontinuum generation. The nonlinear coefficient of the proposed PCF is at the wavelength of 1.55µm. Chalcogenide glasses are known to have both high transparency and nonlinearity in a wide range of infrared wavelengths compared to silica glasses.
Farkhonde Jabbari; Behnam Mohammadi-ivatloo
Volume 8, Issue 4 , November 2014, Pages 17-25
Abstract
Nowadays, due to increased consumption and operation of electric power systems close to their stability boundaries, power systems may become unstable during severe disturbances. So, it is very important to determine the stability margin under different conditions. In this paper, the static voltage stability ...
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Nowadays, due to increased consumption and operation of electric power systems close to their stability boundaries, power systems may become unstable during severe disturbances. So, it is very important to determine the stability margin under different conditions. In this paper, the static voltage stability of an interconnected power system considering load and generation uncertainties is evaluated using probabilistic power flow. The Monte Carlo Simulation method is used to generate the probabilistic power flow scenarios. Then, the expected static voltage stability index and probability of stability for all of the PQ buses are obtained. Also, the standard deviations of the stability indexes are calculated. Finally, the critical PQ nodes are determined under given disturbance. The study has been carried out on 39-Bus New England and 118-bus IEEE test systems and results are presented. 静态电压稳定性评估利用概率潮流确定临界PQ客车抽象如今，由于消费增加，并接近其稳定边界电力系统的运行，电力系统可以在发生严重故障时变得不稳定。所以，为了确定不同条件下的稳定性裕度是非常重要的。在本文中，一个相互联系的电力系统静态电压稳定考虑负荷和发电的不确定性是用概率潮流计算。蒙特卡罗仿真方法被用于产生概率功率流场景。然后，得到所有PQ公交车的预计静态电压稳定指标和稳定的概率。此外，稳定性指标的标准偏差被计算。最后，该临界PQ节点给出干扰下测定。该研究已在39总线新英格兰和118总线的IEEE测试系统进行，并且结果。
Kadali Ravi Kumar; Sydulu Maheswarapu
Volume 8, Issue 4 , November 2014, Pages 1-26
Abstract
This paper puts forward the implementation of Cubic lattice structured multiagent based PSO algorithm (CLSMAPSO) to obtain the optimal power flows by optimally placing TCSC devices. The Thyristor Controlled Series Capacitor (TCSC) is modeled using susceptance model with modifications in the Y bus of ...
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This paper puts forward the implementation of Cubic lattice structured multiagent based PSO algorithm (CLSMAPSO) to obtain the optimal power flows by optimally placing TCSC devices. The Thyristor Controlled Series Capacitor (TCSC) is modeled using susceptance model with modifications in the Y bus of the Newton Raphson Algorithm. The constraints related to violation limits, minimization of line overload factor, and line loss are dealt using penalty factor approach. The new multi agent based cubic lattice structured PSO algorithm was considered for optimizing power flows while satisfying all the constraints mentioned above. This algorithm was tested on IEEE14, IEEE 30 and IEEE 57 bus systems to identify the suitable location, its reactance value and firing angle. The results obtained were quite encouraging and will be useful in electrical restructuring.
Zahra Moravej; Hossein Kiani Rad
Volume 8, Issue 4 , November 2014, Pages 27-35
Abstract
Abstract- This paper presents a new method for solving Substation Expansion Planning (SEP) problem using three basic algorithms in fuzzy clustering. Clustering algorithms are mainly associated with distance functions and measure dissimilarities of data set in different clusters. It is equivalent to measure ...
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Abstract- This paper presents a new method for solving Substation Expansion Planning (SEP) problem using three basic algorithms in fuzzy clustering. Clustering algorithms are mainly associated with distance functions and measure dissimilarities of data set in different clusters. It is equivalent to measure similarities of data in a cluster. That is, a lot of varieties exist to find and create such arranged clusters. The proposed clustering algorithms are Hard C-Means (HCM), Fuzzy C-Means and Possibilistic C-Means. At first, each algorithm is introduced and the differences are characterized. Objective function and optimization procedure of each algorithm are described afterward. Proper evaluation was done by simulating each algorithm. On the other hand, one of the complex and difficult issues in power systems is to find an appropriate response for substation expansion planning. By inspiring from HCM clustering method and by adding some necessary constraints, a new method was developed for solving SEP problem.The proposed method was applied to a typical network and good results were obtained. The results showed that the proposed method was highly effective in dealing with large networks. One of the features of this method is the possibility of introducing the location of new substations during the substation expansion planning. The fast convergence, conformity of solution with engineering perspectives, consideration of real-world networks limitations as problem constraints and simplicity in applying to real networks are the other features of the proposed method.
Babak Yousefi-Khangah; Saeed Abapour; Shahram Yousefi-khangah
Volume 8, Issue 4 , November 2014, Pages 37-45
Abstract
If determination of location and size of Distributed Generation (DG) are applied accurately, the DG’s ability will improve the network situation and reduce operation costs. In this paper, various market conditions are considered to maximize the benefit of DG’s presence and make a trade off among ...
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If determination of location and size of Distributed Generation (DG) are applied accurately, the DG’s ability will improve the network situation and reduce operation costs. In this paper, various market conditions are considered to maximize the benefit of DG’s presence and make a trade off among advantages of DG, network situation, and Distribution Company (DISCO) owners. To determine the optimal location and size of DG, two methods of the cost minimization and the nodal pricing are combined. In addition to evaluating the impact of parameters such as variation of energy price and load on objective function, effect of these parameters on location and size of DG is considered. To confirm the results, impact of loads which are dependent on voltage and variation of the power factor of the DG units is applied and then Effect of power factor on optimal location and size of DG is shown. A method is proposed for convergence of different results which is caused by different power factors. To observe long-term impact of the DG’s presence in the network, a load growth for five years is considered annually. Study is carried out on IEEE-30 bus test circuit.
Hajar Bagheri Tolabi; Mohd Hasan Ali
Volume 8, Issue 4 , November 2014, Pages 47-57
Abstract
This paper presents a new method for optimal multi-objective reconfiguration of distribution system based on the novel Intelligent Water Drops (IWD) algorithm in order to mitigation of losses, improving the voltage profile and equalizing the feeder load balancing. The proposed method is validated at ...
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This paper presents a new method for optimal multi-objective reconfiguration of distribution system based on the novel Intelligent Water Drops (IWD) algorithm in order to mitigation of losses, improving the voltage profile and equalizing the feeder load balancing. The proposed method is validated at nominal load by implementing on a 33 bus test system. The obtained results prove the proposed technique is more accurate than other well known methods such as Genetic Algorithm, Particle Swarm Optimization, and Harmony Search algorithm meanwhile it has an efficient convergence property in compared with other intelligent search algorithms.
Alireza Tabrizizadeh; Fariba Bahrami; Mohammad Javad Yazdanpanah
Volume 8, Issue 4 , November 2014, Pages 59-65
Abstract
In this paper a locomotion control system for bipedal robot is proposed to provide desirable walking on a terrain and skipping over a pitfall preventing the robot from falling in it.The proposed strategy is a combination of motion optimization based on particle swarm optimization algorithm and utilization ...
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In this paper a locomotion control system for bipedal robot is proposed to provide desirable walking on a terrain and skipping over a pitfall preventing the robot from falling in it.The proposed strategy is a combination of motion optimization based on particle swarm optimization algorithm and utilization of mode switching at a higher level controller.The model for biped robot is a compass gait model but the method presented is general and could be appropriatly extended and generalized for other complicated models.
Hamed Hosseinnia; Dariush Nazarpour; Masoud Rezaei Benam
Volume 8, Issue 4 , November 2014, Pages 67-72
Abstract
The reason that cogeneration is being used more compared to separate heat and power is because it is more efficient. In this paper the goal is finding the optimized CHP system utility size and thermal storage considering reliability limits of boiler and grid connected bus. Loss of Load Expectation ...
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The reason that cogeneration is being used more compared to separate heat and power is because it is more efficient. In this paper the goal is finding the optimized CHP system utility size and thermal storage considering reliability limits of boiler and grid connected bus. Loss of Load Expectation (LOLE) and Expected energy not supplied (EENS) are considered as two reliability indices to insure the security of operation. non-sequentional Monte carlo simulation method is introduced to the reliability assessment of CHP,and a normal distribution electrical load model is built to simulate the hourly electrical load.CHP model combined with a two-state reliability model is applied to monte carlo simulation method, and results show that the CHP reliability model works well with non-sequential monte carlo simulation. Non-Sequential Monte Carlo method is used to generate scenarios. Also in order to reduce computation time and due to the large number of scenarios, a scenario reduction technique is used. GAMS software is used for optimization object.
Mehdi Jalali; Saeed Abapour; Kazem Zare
Volume 8, Issue 4 , November 2014, Pages 73-82
Abstract
In this paper, we applied the Data Envelopment Analysis (DEA) ranking method to have efficient placement of Distributed Generation (DG) in distribution network. In this regard first an analytical method to find the optimal size of DG in the network is used to reach the lowest possible losses. In this ...
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In this paper, we applied the Data Envelopment Analysis (DEA) ranking method to have efficient placement of Distributed Generation (DG) in distribution network. In this regard first an analytical method to find the optimal size of DG in the network is used to reach the lowest possible losses. In this paper, benchmarks such as improvement of voltage profile, reducing energy not supplied value (as an index of reliability), reducing environmental pollution, and values related to the purchase and installation costs of DG equipment in each busses for selecting the appropriate DG location are considered, in addition to the network loss reduction. This method has been used because the loss reduction of whole the network will not be a complete criteria for selecting the best location to install DG, The necessarily node which has the highest reduction in power losses cannot be considered suitable node for the installation of DG. Therefore we used DEA to determine the most effective location for DG placement. The proposed method is implementation over the network of 33 buses and the results are presented. GAMS software is used for the simulation results extraction.
Ebrahim Shabanpoor; Hossein Emami; Seyed Ali Hashemi
Volume 8, Issue 4 , November 2014, Pages 83-94
Abstract
Passive defense in appropriate location of base transceiver station in Tehran is the main subject of this article. According to the GSM network architecture and its components, BTS is the most vulnerable part of this network. Under investigating current circumstances of BSCs and BTSs in Tehran an optimization ...
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Passive defense in appropriate location of base transceiver station in Tehran is the main subject of this article. According to the GSM network architecture and its components, BTS is the most vulnerable part of this network. Under investigating current circumstances of BSCs and BTSs in Tehran an optimization of the deployment of these stations are examined regardless of the passive defense and with considering this issue. In determining location of base transceiver stations in Tehran, according to different modes of sharing, a model is designed in which the number of stations is causatively reduced. In addition, temporary Base Transceiver Stations and their variants are presented. Finally, a comparison of the results of the previous researches and this study show the proposal plan is advanced in terms of beautifying the city, economical aspects and defensive schemes. RAN sharing is a kind of sharing in which operators share towers, antennas and Back Hall up to the connecting dots of telecommunication core of operators’ network. This sharing has a particular importance both in terms of reducing the number of base transceiver stations and also reducing operators' costs. KEYWORDS: Passive defense, BTS, Investigation on the location, sharing sites.
