@article { author = {Tarihi, A. and Haghighi, H. and Shams Aliee, F. and Setarenejad, A.}, title = {Macrophage+: A game with a purpose for applying human intelligence in control mechanisms}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {2985-3004}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2020.50799.1874}, abstract = {Originally, control mechanisms were proposed to replace the need for human intervention in operational environments, and thus, enhance the precision and reaction time. Nowadays, new requirements in computer systems such as adaptation have made the design of control mechanisms more challenging. The Observer/Controller pattern is one of the control mechanisms proposed to control many interacting independent elements by making intelligent decisions. An important challenge in designing these mechanisms is that the knowledge needed for decision making is provided by experts; therefore, the process becomes time consuming and costly, depending on the availability of experts and their costs. In this paper, we hypothesize that employing a Game With A Purpose can help to improve the process of providing knowledge in such control mechanisms by using crowd-sourcing and involving non-expert humans in an enjoyable manner. This hypothesis has been investigated by Macrophage+, a Game With A Purpose implemented for this goal. We conducted experiments evaluating Macrophage+, focusing on both its applicability and effectiveness in the context of the observer/controller pattern as well as its enjoyability for the players. The results show that Macrophage+ is a successful Game With A Purpose that involves non-expert humans in the application of the observer/controller pattern.}, keywords = {Control mechanisms,Observer/Controller pattern,Human-based computation,Game with a purpose,crowdsourcing,Interactive game}, url = {https://scientiairanica.sharif.edu/article_21719.html}, eprint = {https://scientiairanica.sharif.edu/article_21719_aa79b69dc535747b145dc8058b9e319d.pdf} } @article { author = {Rezaei Ravari, M. and Eftekhari, M. and Saberi Movahed, F.}, title = {ML-CK-ELM: An efficient multi-layer extreme learning machine using combined kernels for multi-label classification}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3005-3018}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2020.53490.3263}, abstract = {Recently many neural network methods have been proposed for multi-label classification in the literature. One of these recent researches is the multi-layer extreme learning machines (ML-ELM) in which stack auto encoders have been used for tuning the weights. However, ML-ELM suffers from three primary drawbacks: First, input weights and biases are chosen randomly. Second, the pseudo-inverse solution for calculating output weights will cause to increase the reconstruction error. Third, memory and execution time of transformation matrices are proportional to the number of hidden layers. In this paper multi-layer kernel extreme learning machine, that uses a linear combination of base kernels in each layer, is proposed for multi-label classification. The proposed approach effectively addresses the above-mentioned drawbacks. Furthermore, multi-label classification data inherently have multi-modal aspects due to the variety of labels assigned to each instance. Applying a combination of different kernels is the added advantage of ML-CK-ELM that leads to implicitly assess the inherent multi-modal aspects of multi-label data; each kernel can be effectively used to cover one of the modals better than the other kernels. The empirical study indicates that ML-CK-ELM represents competitive performance against other state-of-the-art methods, and experimental results over multi-label datasets verify the feasibility of ML-CK-ELM.}, keywords = {extreme learning machine,Kernel learning,Multi-label learning,Neural network,Linear combination}, url = {https://scientiairanica.sharif.edu/article_21899.html}, eprint = {https://scientiairanica.sharif.edu/article_21899_2de15dbaab3ac9fd2374e8189085c8df.pdf} } @article { author = {Khosrobeigi, Z. and Veisi, H. and Ahmadi, H.R. and Shabanian, H.}, title = {A rule-based post-processing approach to improve Persian OCR performance}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3019-3033}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2020.53435.3267}, abstract = {Optical Character Recognition (OCR) is a system to convert images including text into an editable text. Nowadays, the accuracy of these systems is acceptable in images with simple-structure and high quality. However, the performance degrades for images with complex-structure, low quality, and in the presence of noise, scratches, pictures, stamps, or other non-textual symbols. This paper proposes a Persian OCR post-processing technique to increase the accuracy of the OCR systems dealing with real-world challenging samples. The proposed method extracts five features in each line of the text and uses seven proposed rules to investigate whether that line should be ignored or not. To evaluate the proposed method, Khana (structural based) and Bina (deep learning-based) Persian OCR systems have utilized, and a dataset containing 200 complex-structure images and 100 simple-structure images have been collected. The accuracy of the Khana and Bina in images with complex-structure is 39% and 58%, respectively, while after applying the proposed post-processing method the accuracy increases to 93% and 91%, respectively.}, keywords = {Persian Optical Character Recognition,Post-processing,Complex-Structure Images}, url = {https://scientiairanica.sharif.edu/article_22016.html}, eprint = {https://scientiairanica.sharif.edu/article_22016_f5a46fb93b59611f0d6bdd35a7db178a.pdf} } @article { author = {Biswas, A. and Ekici, M. and Sonmezoglu, A. and Zhou, Q. and Moshokoa, S.P. and Belic, M.}, title = {Optical solitons in birefringent fibers with four-wave mixing by extended trial equation method}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3035-3052}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2018.21144}, abstract = {This paper obtains optical soliton solutions in birefringent bers that are studied in presence of four-wave mixing.The extended trial function scheme is the integration algorithm that is applied. Both Kerr law and parabolic laws are taken into account. The soliton solutions are presented with relevant integrability criteria.}, keywords = {birefringent Fibers,four-wave mixing,extended trial fun}, url = {https://scientiairanica.sharif.edu/article_21144.html}, eprint = {https://scientiairanica.sharif.edu/article_21144_542153ae703058005411ff8679bb7c9e.pdf} } @article { author = {Arslan, S. and Gurdal, O. and Akkaya Oy, S.}, title = {Design and optimization of tubular linear permanent-magnet generator with performance improvement using response surface methodology and multi-objective genetic algorithm}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3053-3065}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2018.50093.1506}, abstract = {Linear generators are electric machines which generate electrical energy from linear movement. Since these machines can lift gear wheel or power train, they have begun to be used widely nowadays. Since their working areas differ according to speed and power characteristic, this study contains design and optimization of tubular linear generator for free piston practices. The design performed response surface optimization through design variables acquired as a result of sizing via interface. The association between the determined design variables and the sizes of generator output was examined. In addition, these sizes were used for objective functions of increasing efficiency, decreasing overall volume and increasing general performance and their optimum values were found by using Multi-Objective Genetic Algorithm. Initial and optimum design data were compared with Ansys Maxwell 2D. With overall performance increase, 22,78% decrease was seen in total mass, while 11,7% decrease was seen in cost. In addition, prototype linear generator was made in line with initial geometry data and it was applied with crank slider mechanism.}, keywords = {Linear generator,permanent magnet,Finite Element,Multi-Objective Genetic Algorithm (MOGA),optimization}, url = {https://scientiairanica.sharif.edu/article_21096.html}, eprint = {https://scientiairanica.sharif.edu/article_21096_939ad6c7d139bfc1ff397de6de9d42fe.pdf} } @article { author = {Qari, H. and Khosrogorji, S. and Torkaman, H.}, title = {Optimal sizing of hybrid WT/PV/diesel generator/battery system using MINLP method for a region in Kerman}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3066-3074}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2019.50176.1555}, abstract = {Abstract— Renewable resources have attracted attention due to different reasons like reducing pollution, improving technical issues. Using several resources along with each other requires studying different aspects. One of the most important issues in hybrid systems is system optimality. Therefore, the most effective approach is to combine components to minimize the cost. Different approaches have been proposed for determining the size of hybrid system components to optimize the proposed system. These methods are classified into three categories: classic, artificial intelligence and computer program methods. In this paper, the optimal size of components is obtained using MINLP method. Outputs of this algorithm are compared with two other algorithms and advantage of this method is proved. This paper gives better responses in a shorter time.}, keywords = {Renewable Energy,Hybrid System,optimization,MINLP Method,GAMS}, url = {https://scientiairanica.sharif.edu/article_21220.html}, eprint = {https://scientiairanica.sharif.edu/article_21220_4d6474129a0169b916737f6aef494522.pdf} } @article { author = {kaplan, Y.A.}, title = {Determination of Weibull parameters using the standard deviation method and performance comparison at different locations}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3075-3083}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2019.50323.1632}, abstract = {This study analyzed the harmony of the Weibull Distribution Function (WDF) and the real data obtained from three different locations. The Standard Deviation Method (SDM) was used to determine the coefficients of the WDF at Adana, Osmaniye and Hatay regions. One of the important purposes of this study is to observe how the performance of the SDM changes in regions with different mean wind speeds. The statistical fittings of the calculated and measured wind speed data were evaluated for justifying the performance of the SDM. The obtained results were compared with such error analyses as Coefficient of Determination (R2), Mean Percentage Error (MPE) and Root Mean Square Error (RMSE). Obtained data were examined on monthly, seasonal and annual bases. The power density is a major key issue for suitability use of wind energy. The calculated power densities of all selected regions were compared with wind power density derived from measured wind data. The performance of the method mentioned in this study was examined in detail at different regions with different geographic characteristics. For the selected three regions, the performance of the SDM was evaluated at different mean wind speeds varying over the years.}, keywords = {Weibull distribution function,Standard deviation method,Wind energy potential}, url = {https://scientiairanica.sharif.edu/article_21381.html}, eprint = {https://scientiairanica.sharif.edu/article_21381_86a4b4f614077a79f2a3edd0d72c4a08.pdf} } @article { author = {Behjati Ardakani, S. and Faez, R.}, title = {Spaser Based on Graphene Tube}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3084-3095}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2019.50322.1635}, abstract = {In this paper, we propose a structure for graphene spaser and develop an electrostatic model for quantizing plasmonic modes. Using this model, one can analyze any spaser consisting of graphene in the electrostatic regime. The proposed structure is investigated analytically and the spasing condition is derived. We show that spasing can occur in some frequencies where the Quality factor of plasmonic modes is higher than some special minimum value. Finally, an algorithmic design procedure is proposed, by which one can design the structure for a given frequency. As an example, a spaser with plasmon energy of 0.1 eV is designed.}, keywords = {plasmonics,graphene,spaser,Quantum optics,Quantum wire}, url = {https://scientiairanica.sharif.edu/article_21257.html}, eprint = {https://scientiairanica.sharif.edu/article_21257_8d4a2a1cfd4b024e60e0f33370a62ceb.pdf} } @article { author = {Das, D. and Bhattacharya, A. and Narayan Ray, R.}, title = {Quasi-oppositional symbiotic organisms search algorithm for different economic load dispatch problems}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3096-3117}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2018.50766.1855}, abstract = {In this paper, an effective meta-heuristic technique called Quasi-Oppositional Symbiotic Organisms Search is applied for solving non-convex economic dispatch problems. Symbiotic Organisms Search is a soft computing technique, inspired by organisms in the ecosystem. This technique is implemented for improving the solution quality in minimum time. In order to improve convergence rate, quasi-reflected numbers are used here instead of pseudo-random numbers. Different equality and inequality constraints such as transmission loss, load demand, prohibited operating zone, generator operating limits and boundary of ramp rate are considered here. Presence of multiple fuels and valve point are also considered in some cases. This algorithm is applied to four different test systems. Simulation results are compared with many recently developed optimization techniques to show the superiority and consistency of this method. Simulation results also show that the computational efficiency of this algorithm is much better than the other meta-heuristic methods available in the literature.}, keywords = {Economic Load Dispatch,Opposition-based learning,Prohibited operating zone,Symbiotic Organisms Search,Valve point loading}, url = {https://scientiairanica.sharif.edu/article_21065.html}, eprint = {https://scientiairanica.sharif.edu/article_21065_361b2b5f54ad164e521e11d217387929.pdf} } @article { author = {Yildiz, M.Z. and Asadi Dereshgi, H. and Kamanli, A.F.}, title = {A Novel Inductive Tactile Probe Design for Lump Detection in Soft Tissue Phantoms}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3118-3127}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2018.51116.2013}, abstract = {The purpose of this study is the development of a novel tactile probe for detection of lumps in soft tissue. The tactile probe includes an inductive sensor inside of an artificial tissue-like silicon rubber cushioning and a square shaped multi-metal-array to increase sensitivity. Firstly, a thermoplastic polymer probe was fabricated for housing and the mechanical compression test was executed by material testing machine. Secondly, the tactile sensor was calibrated between 2.5N-25N by 2.5N incremental steps and showed 99.49% linear behavior. In order to measure probe’s performance, 16 cylindrical silicon phantoms were used in three different scenarios. Each phantom was embedded by hard plastic inclusions at different depths and sizes. Finally, human palpation experiments were conducted by 10 naive subjects for the same scenarios above. The comparison results showed that especially for deep inclusions at low forces, human subjects had high false diagnose rates, while the tactile sensor could detect the deep inclusions at all force levels (ANOVA, p}, keywords = {Tactile imaging probe,inductive tactile sensor,human palpation,lump detection,Psychophysics}, url = {https://scientiairanica.sharif.edu/article_21193.html}, eprint = {https://scientiairanica.sharif.edu/article_21193_b2f42dd99443b28ea70e863f1c687dc5.pdf} } @article { author = {Bina, M.A. and Gitizadeh, M. and Mahmoudian, M.}, title = {High-accuracy power sharing in parallel inverters in an islanded microgrid using modified sliding mode control approach}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3128-3139}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2019.51162.2038}, abstract = {Increasing the penetration level of distributed generation (DG) units in micro grids which feeds the large loads in parallel connections creates the concept of power sharing phenomena in recent researches. In island mode of micro grid the voltage and the frequency control are done using the high inertia inverter. Therefore, the internal control loop is executed in such way to avoid all of DGs not to be overloaded. consequently, the reactive power-sharing error is eliminated and the voltage is also kept constant within the permissible range. This paper, presents a modified control method based on sliding mode approach. The proposed control method is tested using several different disturbances and three scenarios. Also, the fractional order calculus is applied to proposed control strategy to increase the convergence speed and the system accuracy. finally, the proposed method is compared to other well-known controlling approaches while the achieved results confirms the superiority of proposed one.}, keywords = {Distributed generation unit,Micro grid control,power sharing,Sliding mode,Control}, url = {https://scientiairanica.sharif.edu/article_21266.html}, eprint = {https://scientiairanica.sharif.edu/article_21266_91c59e70c360ddbfd6d772a233361c53.pdf} } @article { author = {Zare Chavoshi, A. and Ganji, B.}, title = {Instantaneous thrust control of linear switched reluctance motors with segmental translator}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3140-3149}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2019.51380.2144}, abstract = {The linear switched reluctance machine (LSRM) has all advantages of rotary switched reluctance machine including simple and rugged structure, absence of magnetic material and windings on translator, high reliability and appropriate performance over a wide range of speed. Like rotary switched reluctance motor with segmental rotor, segmental translator linear switched reluctance motor (STLSRM) has capability to produce higher output power/weight in comparison to the conventional linear switched reluctance motors. Due to high advantages of the STLSRM drive, various control algorithms including current control, model predictive control, direct force control, universal control and force distribution function are investigated for the first time to control the instantaneous thrust of this motor. Applying these algorithms to a typical three-phase STLSRM, simulation results are presented and they are compared together from the force ripple reduction point of view.}, keywords = {Linear switched reluctance motor,segmental translator,thrust control,modeling,Finite Element Method}, url = {https://scientiairanica.sharif.edu/article_21226.html}, eprint = {https://scientiairanica.sharif.edu/article_21226_0b27c0f8ef38c5d2fd0673c6a218b129.pdf} } @article { author = {Gorginpour, H.}, title = {Design modifications for improving modulation flux capability of consequent-pole vernier-PM machine in comparison to conventional vernier-PM machines}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3150-3161}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2019.51473.2198}, abstract = {The Vernier PM (VPM) machine is known as a high-torque and low speed drive solution suitable for direct-drive applications such as electric vehicles and wind turbines. The Consequent-Pole Vernier PM (CP-VPM) machine is a special structure of VPM that also introduces high torque density as the conventional VPM incorporating significantly lower volume of PM materials. Although many researches and experiment studies, especially in recent years, reported concerning the conventional structure, there are little publications on the CP-VPM machine. The paper presents the electromagnetic principles of modulation flux occurring in CP-VPM machine. The operating quantities are evaluated using analytical equations and compared with the conventional machine performance. It is concluded that the torque density and back-EMF are much larger than the conventional machine and the torque pulsation magnitude is lower. However, the power-factor is undesirably reduced due to higher spatial harmonics distortion of the CP rotor magnetic field and presence of magnetic field components that do not contribute in the flux modulation. Based on the spatial harmonic analysis, design modifications for enhancing the operational characteristics of the CP-VPM machine are proposed and their effectiveness is verified through comparing the 2D-FE results with the results of the conventional VPM machines.}, keywords = {Consequent-pole Vernier-PM machine,flux modulation,Flux density distribution,Finite Element Method,spatial harmonics}, url = {https://scientiairanica.sharif.edu/article_21224.html}, eprint = {https://scientiairanica.sharif.edu/article_21224_954f8127bcb69df6457cc29d1fca929d.pdf} } @article { author = {Verma, P. and Garg, R. and Mahajan, P.}, title = {Asymmetrical fuzzy logic control-based MPPT algorithm for stand-alone photovoltaic systems under partially shaded conditions}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3162-3174}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2019.51737.2338}, abstract = {Partial shading conditions (PSCs) in Photovoltaic (PV) system is an inevasible situation which curtails the PV array output by exhibiting multiple peaks in its Power-Voltage (P-V) curve. The multiple peaks consist of a single global maximum power point (GMPP) and many local maximum power points (LMPP). The presence of multiple peaks makes tracking of maximum power point more difficult and demands an efficient controller to track the global peak of the P-V curve. In the present work, a novel intelligent asymmetrical Fuzzy Logic Control (AFLC) based maximum power point tracking (MPPT) algorithm has been proposed for tracking GMPP. The fuzzy membership functions of the proposed algorithm have been optimized using a heuristic approach. The algorithm has been designed, developed and analyzed using MATLAB/Simulink. Furthermore, to establish the superiority of proposed AFLC algorithm, it has been compared with conventional perturb & observe (P&O) algorithm and intelligent Fuzzy Logic Control (FLC) based algorithm for GMPP tracking and shading losses under standard test condition (STC) and partially shaded conditions.}, keywords = {Solar Photovoltaic system,Perturb and Observation algorithm,Fuzzy and Asymmetrical Fuzzy algorithm,Shading loss,DC-DC Boost Converter}, url = {https://scientiairanica.sharif.edu/article_21273.html}, eprint = {https://scientiairanica.sharif.edu/article_21273_b571485615bb1bb9c32e7c1d1f20eec8.pdf} } @article { author = {Bhattacharjee, K. and Patel, N.}, title = {An experimental study regarding economic load dispatch using search group optimization}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3175-3189}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2019.51798.2367}, abstract = {Power System network is formed mainly to generate power from all the generators to fulfil total load demand and transmission line losses. The Economic Load Dispatch (ELD) problem is considered to be one of the most important problems of cost minimization in power system operations. Various approaches have been taken to solve the ELD problem. In this paper a powerful Search Group Optimization (SGO) technique is implemented to solve the ELD problem. SGO maintains a good balance between the exploitation and the exploration phases of the technique. This optimization technique tends to find the promising regions of the search space from the first iteration onwards. The algorithm uses five important steps to reach the optimal solution of the ELD problem. Namely, initial population, initial selection of search group, search group mutation, family generation and new search group selection. Using these five steps, the SGO tends to make a smooth transition towards the optimized solution. The SGO is applied to five test systems and the final results obtained have been compared to various other recently developed optimization techniques. The results prove the robustness, feasibility, effectiveness and efficiency of SGO in terms of computational time and proximity to the global optimum solution.}, keywords = {Economic Load Dispatch,optimization,Prohibited operating zone,Search Group Optimization,Valve-point loading}, url = {https://scientiairanica.sharif.edu/article_21279.html}, eprint = {https://scientiairanica.sharif.edu/article_21279_f9c083b067a286750cc6915237f90adf.pdf} } @article { author = {Prasad, M. and Akella, A.K. and Abdelaziz, A.Y.}, title = {Design and analysis of solar photovoltaic-fed Z-source inverter-based dynamic voltage restorer}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3190-3203}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2019.51096.2000}, abstract = {Impedance source inverter or Z-source inverter (ZSI) is an emerging power electronic device. The one kind of feature of ZSI is that dissimilar the conventional inverters such as voltage source inverter and current source inverter it can be open and short-circuited which provides a mechanism for the main circuit to step-up and step-down the voltage as wanted. This work introduces a solar photovoltaic fed Z-source inverter (ZSI) based Dynamic Voltage Restorer (DVR) for the alleviation of destructive voltage swell and harmonics under sudden addition of a balanced three-phase nonlinear load. This article also focuses on perturbation and observation (P&O) method for automatically find the PV systems operating voltage that produces a maximum power output. The design, modeling, and simulation of the proposed PV-ZSI-DVR are implemented in MATLAB/SIMULINK for mitigation of voltage swell and harmonics balanced three-phase nonlinear load and the obtained results are compared with traditional SPV fed voltage and current source inverter based DVRs.}, keywords = {Dynamic voltage restorer,Perturb & observe,Maximum power point tracking}, url = {https://scientiairanica.sharif.edu/article_21272.html}, eprint = {https://scientiairanica.sharif.edu/article_21272_d62b5ca4bed7f031fb3f427ccd543fd0.pdf} } @article { author = {Halvaei Niasar, A. and Nik Khah, H. and Eshrat Abadi, F.}, title = {Technical and economic considerations for the application of permanent magnet brushless motors in evaporative water coolers}, journal = {Scientia Iranica}, volume = {27}, number = {6}, pages = {3204-3217}, year = {2020}, publisher = {Sharif University of Technology}, issn = {1026-3098}, eissn = {2345-3605}, doi = {10.24200/sci.2018.51729.2334}, abstract = {Evaporative coolers due to their low cost are used in hot and dry regions of many countries especially in Iran. Conventional evaporative coolers use single-phase induction motors (SPIMs). But the benefits of these motors are very low, and their substitution with high efficient electrical motors is considered by industrial parties. In this paper, the details of using the brushless motor in the application of evaporative cooler are presented. A 1/2 hp brushless motor and drive are designed and built. This motor- drive is tested by a dynamometer and standard testing equipment. Also, for the approval of this motor-drive, a 5000 m3/h direct evaporative water cooler equipped with this motor is examined under the airflow rate test in the reference laboratory. The results obtained in both tests are compared with the test results of a typical SPIM. The results verify an increase of at least 60% for energy efficiency compared to evaporative coolers equipped with SPIM. Moreover, a new control scheme based on power control instead of speed control is proposed to stabilize the outlet airflow rate. The results indicate that use of brushless motors in this application can offer considerable energy saving, and helps to protect environment.}, keywords = {energy efficiency,electric drive,energy saving,evaporative cooler,Power quality,permanent magnet brushless motor}, url = {https://scientiairanica.sharif.edu/article_21131.html}, eprint = {https://scientiairanica.sharif.edu/article_21131_d6843896ffa2b38755ae77d07794e656.pdf} }