Hassan Moradi CheshmehBeigi

In this thesis, a novel artificial intelligence-based method is proposed for fast and accurate fault detection in three-phase three-level inverters. This approach analyzes current and voltage signals, extracts key features, and employs machine learning algorithms such as Random Forest and SVM to learn the system’s behavior under both normal and faulty conditions, enabling effective fault identification. To evaluate performance, simulations were carried out in the MATLAB/Simulink environment, and the resulting data were used for training and testing the model. The results indicate that the SVM model outperforms the other models used in this study in terms of speed. It is noteworthy that, in addition to achieving high accuracy, the proposed method also demonstrates good generalization capability, which enhances system reliability and reduces maintenance costs in power systems. Furthermore, the method can be further improved in the future through the integration of deep learning and reinforcement learning algorithms.   

Direct current (DC) microgrids have recently attracted more attention from researchers due to their advantages over alternating current (AC) microgrids, such as the absence of transmission losses related to reactive power flow, the absence of harmonic currents, and the simple integration of resources with DC loads. However, the constant exchange of information in the secondary control layer in the cyber environment for voltage recovery and optimal resource management has presented these microgrids with challenges such as high communication costs, the need for high communication bandwidth, and cyber threats. Denial of service (DoS) attacks and false data injection (FDI) attacks are dangerous examples of these threats that can lead the system to instability and even collapse. DoS attacks have extremely destructive effects on the system by temporarily or permanently disrupting access to critical system information. On the other hand, FDI attacks can secretly and noticeably cause harmful disturbances in the system by injecting false data into the transmitted information. In this study, an edge-based event-triggered control structure is proposed as a suitable and optimal alternative for permanent information exchange in second-layer distributed control, which is able to ignore DoS attacks. Based on this structure, information exchange between units occurs only when the sending conditions are met. Also, a decentralized approach based on a multilayer perceptron (MLP) neural network is introduced to detect FDI attacks. The advantages of this approach include high flexibility, reduced information transmission in the cyber environment, reduced complex calculations, and increased information security. Also, a threshold for an FDI attack is determined so that mitigation operations are performed only when the attack occurs. A microgrid consisting of three generating units and a DC voltage bus is simulated under different scenarios to investigate the effectiveness of this study. The results obtained show that the event-triggered (ET) structure is resistant to DoS attacks and the proposed approach is able to detect FDI attacks with high accuracy in the presence of DoS attacks and in the ET communication structure and mitigate its effects. Keywords: Direct Current Microgrids, Denial of Service Attacks, False Data Injection Attacks, Edge-based Event-triggered, Distributed Control, Multilayer Perceptron Neural network

  Modern power systems rely on advanced technologies and communication networks that enable efficient monitoring, control, and operation of physical equipment. These tools offer diverse services in terms of functionality and enhanced reliability; however, their increasing use has led to a rise in vulnerabilities and cyberattacks. Such vulnerabilities have serious consequences, including blackouts and detrimental effects on electrical infrastructure. Therefore, developing effective models for identifying and classifying adverse events in power systems for the prompt issuance of control commands is of great importance. In this context, cyberattacks on SCADA systems, which are widely used for monitoring large production systems and modern power networks, have become a significant challenge. These systems are particularly vulnerable to various cyberattacks due to their unique features, including remote communications and management of critical infrastructure. Detecting these attacks using traditional Intrusion Detection Systems (IDS) is challenging due to the complexity and diversity of threats, highlighting the need for innovative and effective methods for accurate identification of these attacks. In this regard, a two-stage feature selection method utilizing Principal Component Analysis (PCA) and the War Strategy Optimization (WSO) algorithm, along with a Feedforward Neural Network (FFNN), has been proposed. In this method, the number of layers and the number of neurons in each layer of the FFNN are optimally determined by the WSO algorithm. This approach is designed for the precise identification of malicious attacks. The performance of the proposed method has been evaluated using laboratory SCADA system data, and the results demonstrate satisfactory effectiveness in detecting cyberattacks. This research can significantly enhance the resilience and safety of SCADA systems against cyber threats and serve as an effective solution for managing and mitigating risks arising from cyberattacks on critical infrastructure.

Abstract The islanding of interconnected power systems, which is also known as the isolation and breaking of power systems, is the last defense method to deal with the collapse of the system and prevent the occurrence of catastrophic events in the power network, which as a widespread control method is a comprehensive decision problem with There are many details and it is presented as an important part of corrective control strategies. After the occurrence of a major disturbance in a power system, if there is no suitable solution plan and model in time, this disturbance may lead to the total collapse of the system. Islandization of power systems means determining the correct points of isolation of the integrated system into a number of smaller islands if maintaining the integrity of the system is not possible. The aim of this thesis is to provide a method to predict the appropriate time for applying controlled islanding in the network by means of indicators based on the relationships between the generator harmonic groups. The defined indicators can predict the weakening of security and fragility of the network in the context of the dynamic behavior of the system and as a result the islanding of the network with high speed and accuracy and in a timely manner. The IEEE 39 bus network has been used to obtain the critical limit of the introduced indicators in a timely manner and to predict the appropriate time for islanding in a timely manner. The results obtained from the dynamic simulation indicate that the controlled islanding at the right time can prevent the occurrence of consecutive incidents, global blackouts and crises in the network.   

In independent microgrids located in remote areas, the development of reliable and self-sufficient renewable energy systems is one of the major challenges of operating power systems due to the lack of connection with the national power grid. One of the best future options for increasing the use of renewable energies in grid-independent systems is the use of energy storage systems. In this thesis, an optimization model is proposed to determine the most cost-effective combination of renewable energy capacity using the war strategy optimization algorithm in a grid-independent microgrid supported by battery energy storage technology. The problem of energy management has been formulated using linear programming and the proposed algorithm has taken into account the limitations of exploitation, technical and land use. Also, the hourly effects of the region's weather and load demand, along with the installation price, have been evaluated. The simulation results for the diesel-based microgrid, which is a benchmark, and the renewable microgrid based on LCOE (levelized cost of electricity), have been compared and analyzed. In addition, sensitivity analysis is also presented to investigate the effect of variables on LCOE and PC (present cost) of the system. According to the tests and the obtained results, the lowest amount of PC is related to the scenario that has both a reduction in storage costs and a reduction in demand for consumption, which is 2113200 (€). Also, the results in this section show that the renewable microgrid has a higher LCOE (from 0.39 to 0.48 (€/kWh)) than the diesel-based approach (from 0.21 to 0.48 (€/kWh) is watt hours.   

   As we know, the structure of electricity networks around the world is changing and evolving. So that distributed production in the form of micro-grid (MG) is expanding. Normally, an MG consists of several scattered production sources, and energy storage systems (batteries) are used for continuity of energy production in new MGs. In such networks, determining the charging and discharging time of the batteries requires having sufficient information about the state of energy production and consumption or the size of the MG bus voltage. Normally, sensors are used in MGs to get information about the above-mentioned things. Using a sensor in any system reduces its reliability. Because there is a possibility of failure in the sensors. For this purpose, the use of sensorless methods to estimate the MG bus voltage creates better conditions in creating more confidence in the MG's reliable performance. Therefore, in this research, an artificial neural network (ANN) model is proposed for MG modeling. Because A   have shown to be capable of modeling non-linear systems. It should be noted that the MG under study in this work consists of a distributed production unit (solar energy) and an energy storage system unit (batteries). In this way, three ANN models have been created to estimate MG bus voltage. So that the first model estimates the output voltage of the photovoltaic array, the second model estimates the current of the storage system, and the third model estimates the MG bus voltage. To evaluate the performance of the created models, the mean square error (MSE) of each model has been calculated. The test results show that the error of the proposed models is very low and close to zero, which means that the models can predict the output with high accuracy. Finally, it should be said that the accuracy of the first model that estimates the voltage of the photovoltaic array is higher than the other two models.

   ريز شبكه يك شبكه محلي كوچك است كه   از چندين منابع توليد پراكنده و بار تشكيل شده است . از قابليت هاي ريز شبكه قابل كنترل بودن و تامين كننده توان الكتريكي مي باشد و به صورت اتصال به شبكه يا جدا از شبكه مورد استفاده قرار مي گيرد كه از مزايا ي اصلي آن افزايش كيفيت برق و قابليت اطمينان براي مصرف كنندگان مي باشد.يكي از مسائل مهمي كه در ريز شبكه ها از اهميت بالايي برخوردار است كيفيت ولتاژ به دليل افزايش بارهاي تكفاز كه از بارهاي نامتعادل هستند ميباشد.از عواملي كه در كيفيت ولتاژ متاثر است نامتعادلي ولتاژ مي باشد كه عوامل مختلف و متعددي دارد. دربخش اول اين پايان نامه عوامل ايجاد نامتعادلي ولتاژ و اثرات آن بر تجهيزات ريزشبكه شناسايي شده سپس به منظور بررسي ميزان نامتعادلي ولتاژ،استاندارد هاي پركاربرد وتعاريف متعددي از شاخص هاي نامتعادلي ولتاژ مورد توجه قرار مي گيرد.طرح پيشنهادي دراين پايان نامه به متعادل سازي ولتاژ وتحليل ريزشبكه هاي مبتني بر اينورتر مي پردازد.طرح كنترلي استفاده شده به منظور جبران سازي نامتعادلي ولتاژ ناشي از بارنامتعادل ،كنترل افتي مبتني بر فيلتر چند متغيره بهينه شده بوده كه مولفه ي مثبت ومنفي جريان را براي منابع ولتاژ مبتني بر اينورتر به هنگام بروز نامتعادلي در ريزشبكه استخراج مي كند. هدف اين طرح در واقع بهبود عملكرد سيستم كنترل افتي به عنوان قلب سيستم كنترل ريزشبكه جزيره اي تحت شرايط نامتعادلي ولتاژ مي باشد. بدين منظور فيلتر چند متغيره بهينه شده توسط الگوريتم هاي فراابتكاري بر روي سيستم كنترل افتي پياده سازي مي شود تا بتواند مولفه هاي مثبت و منفي حاصل از وجود نامتعادلي را به خوبي شناسايي و جدا سازي كند . با پياده سازي اين سيستم مي توان نوسانات ناشي از نامتعادلي ولتاژ را تا حد زيادي كاهش داد و پايداري سيستم را بهبود بخشيد. اين شبكه به منظور بررسي عملكرد سيستم كنترلي ارائه شده آن با وجود بار نامتعادل در فضاي سيمولينك نرم افزار متلب شبيه سازي شده است. در بخش دوم اين پايان نامه هارمونيك به عنوان مسئله اصلي كه بر كيفيت توان تأثير مي گذارد،مورد توجه قرار مي گيرد و طرح پيشنهادي به آشكارسازي هارمونيك مي پردازد.اين طرح كنترلي كوپل هاي نوساني ايجاد شده بين اجزاي هارمونيك را حذف ميكند.هدف اين طرح بهبودعملكرد كنترل كننده جريان و در نهايت بهبود عملكرد سيستم مي باشد.براي نشان دادن عملكرد موثر طرح پيشنهادي، در فضاي سيمولينك نرم افزار متلب شبيه سازي شده است. وازه هاي كليدي:ريزشبكه جزيره اي ، واحد هاي توليد پراكنده ، نامتعادلي ولتاژ، كنترل افتي ( دروپ) ، فيلتر چند متغيره ، آشكارسازي هارمونيك

In order to increase the reliability in supplying the energy needed by consumers, plans have been proposed regarding the behavior of resources connected to the power grid in recent years, which are called microgrids. Microgrid systems are formed by the combination of several energy production and storage systems and local consumers. These structures have recently attracted attention all over the world, because these networks can work both connected to the national network and independently or in islands, and they can also cover rural consumers or consumers far from the main network. put A large part of the production of these networks is made up of renewable energy sources such as wind turbines and solar panels. Due to the environmental problems and global warming as well as the energy crisis of the last few decades and the movement of governments towards not depending on fossil fuels, the distribution systems have faced an increase in the penetration of scattered productions based on renewable sources such as wind and solar sources. One of the important factors that affects the performance of the microgrid is the uncertainties in its various parts and components. Various uncertainties such as load uncertainty, DG availability, etc., make the management of this network a serious challenge. With the high penetration of DGs based on renewable energies in the microgrid and the dependence of the production power of these sources on weather conditions, the operation of the microgrid has faced serious uncertainty. The presence of these uncertainties has jeopardized the security of system operation. Providing an effective and efficient solution for the safe operation of future distribution systems in conditions of uncertainty is a necessary and necessary thing. One of the main solutions for this purpose is to use an energy storage system, especially batteries, as a supplement for distributed production, especially production based on renewable energy. In addition to maintaining stability, batteries can make the microgrid a more economical option with ESS when the price of electricity is cheap or there is excess production of local resources. In addition to all these advantages, the investment cost of batteries is high and its technologies are improving and introducing new types every year. Due to the relatively low life span of these equipments, along with the cost factor, the life span is also considered as one of the most important factors for choosing batteries. Therefore, choosing the optimal number and place to install batteries, along with the type of technology chosen, is one of the most important challenges for power grid planners. In the proposed plan, a comprehensive and uncertainty-based model is presented to determine the capacity and optimal location of ESS installation in the microgrid with the penetration of renewable energy-based productions. The proposed model also evaluates the type of battery storage source technology. In other words, the proposed structure is proposed based on conventional and widely used battery models, and the effect of these technologies on the location and total cost of the microgrid is evaluated.  

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   به دليل توسعه ذخيره­سازهاي انرژي الكتريكي و منابع توليد پراكنده با خروجي DC و همچنين وجود طيف وسيعي از بارهاي DC ، استفاده از ريزشبكه­هاي DC در حال افزايش است.   تلفات كمتر، عدم نياز به سنكرون­سازي و كنترل فركانس و كنترل اوليه ساده­تر ولتاژ از جمله مزاياي ريزشبكه­هاي DC نسبت به ريزشبكه­هاي AC است. با اين وجود، يك ريزشبكه DC نيز داراي برخي معايب و همچنين پيچيدگي­هاي فني مربوط به بهره­برداري، كنترل و حفاظت مي­باشد. ريزشبكه‌هاي DC   نسبت به ريزشبكه­هاي AC عموماً منطقه جغرافيايي كوچك‌تري را تغذيه مي­كنند و طول خط توزيع كوتاه‌تري دارند و به عنوان شبكه‌هاي مقاومتي در نظر گرفته مي‌شوند؛ همچنين ريزشبكه‌هاي   DC اينرسي كمتري دارند و در نتيجه مستعد ناپايداري در هنگام بروز خطا يا اغتشاش مي­باشند. يكي از مهمترين چالش­ها در ريزشبكه­هاي DC، طراحي يك سيستم حفاظتي مؤثر براي آنهاست. در ريزشبكه­هاي DC، وجود خازن در فيلتر خروجي مبدل­هاي الكترونيك قدرت و خازن نصب شده در مدار ورودي بارها باعث افزايش سريع جريان خطا مي­شوند و در نتيجه، هماهنگي رله­هاي حفاظتي به طور جدي تحت تأثير قرار مي­گيرد. در اين پايان­نامه، يك رله حفاظتي تطبيقي براي تشخيص سريع بروز اتصال كوتاه در ريزشبكه­هاي DC پيشنهاد شده است. طرح حفاظتي پيشنهادي از دو قسمت حفاظت اوليه و حفاظت ثانويه تشكيل شده است. در حفاظت اوليه پيشنهادي، اتصال كوتاه­هاي با مقاومت اتصالي كم (تا حدود يك اهم) را بر اساس نرخ افزايش جريان، شناسايي مي­كند. حفاظت ثانويه پيشنهادي نيز با توجه به جهت جريان در دو سر كابل اتصال كوتاه شده، وظيفه شناسايي اتصالي­هاي با مقاومت اتصالي زياد را به عهده دارد. نتايج شبيه­سازي يك ريزشبكه DC شامل منبع توان فتوولتائيك، كه به شبكه AC متصل است؛ نشان مي­دهد؛ طرح حفاظتي پيشنهادي در كمتر از يك ميلي­ثانيه قادر به شناسايي انواع اتصال كوتاه مي­باشد. همچنين طرح حفاظتي پيشنهادي در برابر تغيير شرايط بهره­برداري از جمله تغيير بار و توان توليدي منبع توليد پراكنده، مقاوم بوده و سيگنال تريپ كاذب صادر نمي­كند.   

   Today, with increasing in the demand for electric energy consumption in the world and the limitation of the use of fossil fuels, the increasing attention of energy producers to the use of clean and renewable sources such as solar energy and wind energy has been attracted, and producers have introduced these resources as alternatives with higher reliability and quality, and better environmental and economic considerations. The use of renewable energy sources to generate electricity requires distributed generation systems in the form of microgrids. Microgrids are composed of distributed generation sources, local loads and energy storage system, and they are able to supply the required load of the system in the mode of direct connection to the national grid or island connection. AC microgrids, DC microgrids and AC/DC hybrid microgrids, are three main structures of microgrids. DC microgrids have received special attention due to their simpler control compared to AC microgrids and AC/DC hybrid microgrids. However, the lack of inertia in the microgrids, especially the DC microgrid in island mode, has caused them to have less resistance and stability margin against disturbances and fluctuations. One of the main issues in DC microgrids is voltage swing control of these microgrids. In this thesis, the design and simulation of an island mode DC microgrid which includes solar energy source, energy storage system and constant power loads is discussed. In this system, a virtual DC machine is used to improve damping and generate inertia. In order to have a stable and optimal performance of DC microgrid against oscillations and also to improve and increase the inertia and damping of the microgrid, a control method based on robust control H?   has been presented, which is able to withstand disturbances and oscillations and finally maintain the stable performance of the system. In order to investigate and analyze the proposed control method, the system studied in this research is simulated with different scenarios such as disturbances and oscillations in Simulink environment of MATLAB software. Evaluation of the simulation results proves the accuracy of the performance and the efficiency of the proposed controller. The proposed strategy by applying inertia and virtual damping, acceptably reduces the voltage oscillations of the DC microgrid and finally improves the stability of DC microgrid.

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AbstractWith the increase in the number ofdistributed generation (DG) and renewable energy resource units (DG/RES) andtheir penetration in distribution networks, microgrids (MG) have become veryimportant. Future of the network stabilityis endangered by increasing the number of Distributed Generation (DG) andRenewable Energy Source (RES) units. The idea of the Virtual SynchronousMachine (VSM) has been raised to control the power electronic-based DG/RESconverters in order to have better integration with the grid. This thesisintroduces a new stabilizer design for VSM-based converters to guarantee thestability of the micro-grid (MG). In this regard, the Sliding Mode Control(SMC) theory, which is robust against the disturbances and uncertainties, isemployed to cope with the intermittent and nonlinear nature of DGs. The mutualoperation of the proposed inverter and MG stabilizer has the followingadvantages: (1) It provides a seamless and robust transition from thegrid-connected to the islanded mode. (2) It is universal, sharing the real andreactive power during islanded mode and acting as a grid-supporting inverter inthe grid-connected mode. (3) It mimics the behavior of the conventionalsynchronous generator resulting in better integration of DGs into the grid. (4)It can be used both in the voltage-controlled and the current-controlledVoltage Source Converters (VSC). (5) It obviates the need for the communicationlinks, Phase Locked Loop (PLL) and islanding detection process. Themathematical model of the whole system has been investigated. The simulationresults, conducted in the SIMULINK/MATLAB environment, confirm theeffectiveness of the proposed controller.Keywords: Microgrid; Sliding modecontrol; Virtual synchronous machine  

   The quality of power and lack of use of the network are considered as two important factors in power networks, and one of the factors of ferroresonance is known as these network disturbances, which with the occurrence of this phenomenon, power quality and network security are endangered. Ferroresonance is one of the rare phenomena in power networks. In this project, first by introducing the phenomenon of ferroresonance, its different random states in the power system are explained, and also the effects in different fields are presented to start sales. Investigating and simulating the ferroresonance phenomenon is dependent on the ferroresonance circuit model and finding its state equations. In this project, by solving these equations, we investigate and simulate the random ferroresonance in the power transformer. Finally, we examine the effect of the initial conditions on this phenomenon in the power transformer. Usually, in the ferroresonance equivalent circuit, the self-impedance of the network and its resistance value are ignored, and in this project, we study the effect of ignoring these parameters.

  در سال­هاي اخير با ظهور ادوات الكترونيك قدرت، منابع مبتني

  One of the major challenges for microgrids that use renewableenergy, such as photovoltaic systems, is the lack of inertia, which endangersthe microgrid stability. In recent years, the virtual synchronous generatormethod has attracted a lot of attention to meet this challenge. In fact, thismethod mimics the transient properties of a synchronous generator using therotational equation of a synchronous generator and helps to improve gridstability by creating virtual inertia. On the other hand, most photovoltaic-virtualsynchronous generator systems have energy storage systems that have issues suchas increased system costs, maintenance costs, and space occupation. Therefore,in this research, a photovoltaic-improved virtual synchronous generator systemis used, which does not require energy storage. Another challenge of microgridsis the voltage imbalance and the proper operation of the control system underunbalanced conditions. So far, various methods have been proposed to compensatethe unbalanced voltage, many of which impose additional costs on the system. Inthis research, using the double decoupled reference frame method, the positiveand negative components of voltage and current are seperated and the PCCvoltage is balanced. In summary, this research presents an island PV-improved VSGsystem that is able to compensate voltage imbalance at the PCC. This system issimulated in the MATLAB / Simulink, and the simulation results show thatsimultaneously the dynamic stability in the transient state is improved usingvirtual inertia, and it is also possible to compensate the unbalanced voltageat the PCC.

  According toforecasts, the world will face an energy crisis and issues related togreenhouse effects and environmental pollution in the near future. Therefore,the use of environmentally friendly vehicles, such as electric vehicles, aswell as the trend towards renewable energy in the future, will be inevitable.According to statistics, 83% of electric vehicles use permanent magnetsynchronous motors. Also in wind turbine applications, the approach of largecompanies in the world such as Siemens and General Electric, is to use largegenerators with high power density and reliability. The share of permanentmagnet synchronous machines (PMSM) is higher than other electric machines. Thereason is the significant improvement in the properties of permanent magnetsand significant reduction in their price in recent years. Due to the popularityof PMSM in the new energy industry, research has started on the design andconstruction of well-functioning drives for these machines. In thisdissertation, the torque control of this machine has been done using the modelpredictive control (MPC) method. The aim of this dissertation is to provide amethod for simultaneously reducing torque ripple and switching frequency with asmaller computational burden than the previous methods. By reducing the torqueripple, the performance of the drive and motor is improved and by reducing thecomputational burden, it is possible to implement this method on a variety ofmicrocontrollers.Keywords: Model PredictionTorque Control, Discrete Space Vector Modulation, Switching Frequency,Permanent Magnet Synchronous Motor

  Today, access to energy is very important for developed and developing countries, and because these resources are in crisis, they cannot be trusted and a solution must be found. Therefore, the use of electric vehicles is a very good option to replace combustion vehicles in order to reduce fuel consumption and provide power in the form of distributed generation. But the point is that the community of electric vehicles at charging stations can have a huge impact on the network, and charging stations can also play a role. On the other hand, the location of charging stations in the network plays an important role in network parameters such as losses and voltage deviations. Also, the probabilistic behavior of load in the network and its changes during 24 hours a day can have a significant impact. Have power on network lines during playback. Therefore, in this dissertation, we first model and review electric car charging stations affected by the behavior of electric car owners by including load uncertainty in the Monte Carlo distribution method, which has been omitted in previous studies. Then, to determine the optimal location and capacity of electric vehicle charging stations in the 33-bus distribution network in order to reduce the negative effects on the network, including increasing network losses (active and reactive) and voltage deviations in the network bus using the algorithm. Gravitational atmosphere is addressed. The results of simulation in MATLAB software environment show an increase in losses and deviation of network voltage by placing electric car charging stations in place and with optimal capacity due to increased current and power passing through the lines. The instrumentation shows that if the charging stations of the electric vehicle are not in the optimal location, the losses and voltage deviations will be much higher than the nominal values ??of the network.

Abstract In a world where the evolution of advanced technology is changing moment by moment, electricity is not only an energy source but also has become an impartible part of human life. Therefore, nowadays with the progress increasing use of renewable energy sources (RESs), as well as creating a balance between production and load demand can be achieved nearly 100 percent efficiency to supply energy from the environment. On the other hand, due to the evolution of power electronic and the introduction of real-time controllers, the implementation of DC systems indicates better performance in power supply. Therefore, the introduction of DC microgrids (DCMGs) can be a suitable alternative solution for AC microgrids. But as we know, RESs, due to their alternative nature as well as their inherent low inertia property, will definitely disturbance with the stability of the microgrid. Therefore, for system stability, which means stabilizing the DC bus voltage in DCMG when an error or malfunction occurs, we have used virtual inertia emulation in the microgrid. The idea of virtual inertia is derived from the implementation of equations based on a real DC machine. This means that we have reached a virtual DC machine (VDCM) unit by using the battery bank with a bidirectional DC/DC converter and applying the desired control method. These equations are applied in the concept of VDCM and by applying to the control system of the converter the interface of the energy storage source with the network. However, it should be noted that the type of converter selected can greatly affect the performance of the VDCM unit. According to studies, the cascaded buck-boost converter (CBBC) is a suitable option for required power transmission. The proposed converter can be considered due to its power density capability, 98 efficiency and higher working temperature, as well as the ability to reverse the working direction when needed for different operating modes. The proposed scheme is implemented in the DCMG islanded. Also, according to the small signal model of the CBBC along with its controller unit, the stability of the microgrid has been analyzed. In order to confirm and be effective, the proposed design in Matlab/Simulink software has been studied under different test scenarios such as sudden change in consumer demand, change in RESs production capacity, and finally simultaneous changes in demand and production. It is evident from the results obtained that the DC bus voltage drop and the mode of operation of the DCMG are completely improved compared to the conventional design and confirm the above claim. Keywords: renewable energy source (RES), DC microgrid (DCMG), virtual DC machine (VDCM), cascaded buck-boost converter (CBBC), DC bus, virtual inertia   

منابع انرژي تجديد­‌­پذير و استفاده از آن­ها در شبكه­هاي توزيع انرژي الكتريكي به ايجاد رويكرد­­­ها و ساختار­هاي جديدي منجر شده­است. قابليت مهم اين ساختارهاي جديد امكان بهره­برداري به صورت سيستم كنترل­پذير مستقل و مجزا از شبكه اصلي است كه با توسعه استفاده از مبدل­هاي الكترونيك­­قدرت امكان­پذير شده­است. از جمله اين ساختارها ريز شبكه مي­باشد كه يك شبكه­ي كوچك ولتاژ پايين يا ولتاژ متوسط است. ريزشبكه براي تغذيه يك مجموعه بار حساس محلي طراحي مي­شود. اجزاي ريزشبكه شامل منابع توليد پراكنده، بارهاي حساس و واحدهاي ذخيره­انرژي مي­باشد كه داراي دو حالت كاري متصل به شبكه و مستقل از شبكه (جزيره­ايي) است. در اين پايان­نامه ابتدا با شبيه­سازي ريزشبكه در حالت مستقل و با بكارگيري روش كنترل افتي از طريق اندازه­گيري ولتاژ و فركانس خروجي مبدل منبع ولتاژ (VSC) و اعمال حلقه كنترل توان اكتيو- ­فركانس، به مسأله تنظيم فركانسي مي­پردازد. براي كنترل فركانسي مهم­ترين بحث، كنترل توان اكتيو مي­باشد. پس از وقوع اغتشاشات عدم توانايي سيستم در حفظ فركانس در يك حد قابل قبولي منجر به عدم تعادل بين توليد و مصرف و در نهايت ناپايداري مي­شود. در حالت ناپايداري امكان دارد به صورت نوسانات ماندگار فركانس ظاهرگردد كه منجر به از مدار خارج شدن منابع توليدي و يا بارها مي­گردد. پايداري ديناميكي سيستم معمولا از طريق اينرسي انرژي جنبشي روتور در ماشين­هاي سنكرون تأمين مي­شود. سپس مبدل منبع ولتاژ با روش­هاي كنترلي ژنراتور سنكرون مجازي ( (VSG مجهز مي­شود، ويژگي­هاي ديناميكي هردو روش كنترلي افتي و ژنراتور سنكرون مجازي بررسي و براي نشان دادن تفاوت آنها در شرايط يكسان،­ هر دو روش كنترلي در حالت مستقل بررسي شده­اند. مدل­سازي سيگنال­كوچك براي مقايسه تغييرات فركانسي اين دو روش كنترلي انجام شده­است. يك روش كنترل افتي اينرسي مشابه ژنراتورسنكرون مجازي مطرح شده­است. تفاوت بين آنها اين است كه با شبيه­سازي معادله نوسان، روش كنترلي ژنراتور سنكرون مجازي داراي اينرسي مجازي است، در حالي كه روش كنترل افتي هيچ اينرسي ندارد. هدف اين طرح تنظيم فركانس و بهبود تقسيم توان با استفاده از اينرسي مجازي سيستم مي­باشد. بنابراين مي­توان بدون تغيير در سخت­افزار سيستم، اينرسي سيستم توان را با انرژي ذخيره شده در خازن­هاي لينك DC مبدل منبع ولتاژ افزايش داد و همچنين با تنظيم ولتاژ دوسر خازن پشيباني فركانس سيستم را فراهم و پايداري را بهبود نمود. به منظور دستيابي به اهداف پايان­نامه، دو اينورتر منبع ولتاژ به صورت موازي با يكديگر در نقطه اتصال مشترك به يك بار اهمي­سلفي متصل مي­شوند. از استراتژي كنترل ژنراتور سنكرون مجازي و تنظيم فركانس با   اينرسي مجازي خازن لينك DC در نرم­افزار متلب شبيه­سازي مي­شود.          واژه هاي كليدي­: ريزشبكه، منابع توليد پراكنده، كنترل افتي، مبدل منبع ولتاژ، ژنراتور سنكرون مجازي، اينرسي مجازي خازن لينك DC   

   امروزه استفاده از خودروها و وسايل نقليه عمومي كه به صورت تركيبي يا كامل از سيستم فتوولتائيك جهت تأمين انرژي استفاده مي‌نمايند بسيار رايج و متداول شده است. از سويي ديگر با توجه به پايين بودن راندمان و گران بودن سيستم‌هاي فتوولتائيك، بهره‌برداري بهينه از اين سيستم‌ها امري ضروري و لاينفك مي‌باشد. در نتيجه، مي‌بايست راهكاري اتخاذ نمود كه در هر شرايطي ماكزيم توان و راندمان را از سيستم‌هاي فتوولتائيك اتخاذ نمود. هزينه بالاي راه‌اندازي اوليه و نيز راندمان پايين تبديل انرژي از جمله معايب استفاده از سيستم‌هاي فتوولتائيك مي‌باشد. براي كاهش معايب فوق تلاش‌هاي بسياري انجام شده و در حال انجام است تا راندمان تبديل انرژي را با افزايش كيفيت سلول‌هاي خورشيدي و نيز دريافت حداكثر توان از سلول‌هاي خورشيدي افزايش دهند. مشخصه‌هاي سيستم‌هاي فتوولتائيك ذاتاً غيرخطي بوده و تابع پارامترهاي محيطي از جمله ميزان تابش، دماي محيط و بار متصل به آن است. لذا با انتخاب مناسب نقطه‌كار آرايه فتوولتائيك مي‌توان در شرايطي كه ميزان تابش و دما ثابت يا متغير است حداكثر توان را از آرايه فتوولتائيك دريافت نمود. تاكنون روش‌هاي بسياري جهت دريافت حداكثر توان از پنل‌هاي خورشيدي پيشنهاد شده است كه يكي از پركاربردترين روش‌هاي اخير در رديابي نقطه ماكزيمم توان سلول‌هاي فتوولتائيك استفاده از روش‌هاي فرا ابتكاري در تخمين نقاط اكسترمم تابع توان خروجي سيستم فتوولتائيك است. با اين وجود، در تمام اين روش‌ها به چالش اساسي متحرك بودن سلول فتوولتائيك و تغييرات سريع شرايط جوي پرداخته نشده است. در اين پروژه، پس از مطالعه مدل ديناميكي دقيق سلول‌هاي خورشيدي وسيستم فتوولتائيك در شرايط جوي متفاوت، يك روش   مبتني بر دريافت ماكزيمم توان به كمك يك الگوريتم هوشمند پيشنهاد مي‌شود كه توانايي دارد به طور پيوسته، سريع و پويا نقطه دريافت ماكزيمم توان خورشيدي در پنل‌هاي فتوولتائيك نصب شده بر روي خودروي در حال حركت با تغيير سريع تشعشع و دما در حالت جزئي سايه‌دار كه يكي از عواملي است كه ميزان دسترسي خورشيد را براي پنل‌هاي فتوولتائيك محدود مي‌سازد و باعث مي‌شود به همه سطوح پنل‌هاي فتوولتائيك تابش و دماي يكسان و يكنواخت نرسد را دنبال نمايد.

The stability of the power system refers to the ability to maintain or return to the working point of the persistent state of the power system when it is disturbed. Turbulence may have a serious effect on the stability of the power system due to the stability of the small signal and the large signal. Increasing the consumption and diversity of consumers of electrical energy in power systems has led to an increase in the amount of energy transmitted in power systems. This increase has led to the interconnectedness of power systems to provide the required energy. In these interconnected systems, low frequency fluctuations can increase. These fluctuations affect the security and stability of large power systems and limit the current of power in the communication lines between the power sub-systems. Normally, synchronous generators maintain a constant vetting and a constant relative angle between stator and rotor coils, which is called synchronous generators in power systems. As soon as disturbances occur, the ability of the synchronum generator to balance the mechanical power of the turbine generator and the electrical power of the load to maintain stability is controlled. Traditionally, in the control of synchronous generators, a power system stabilizer (  ) produces an additional drive signal for the AVR excitation system to drive low frequency fluctuations. The goal is to create more mirant torque. On the other hand, installing    on all production units may lead to unwanted dynamic interactions. Matlab programming to combine probable load spreading analyses, linear modeling of multi-machine power system, small signal analysis and    optimization with pso metaheuristic algorithm for critical generator based on single-way stabilizers that have performance capability To have the best, it will be done.  

   در سالهاي اخير اهميت استفاده از مبدل­هاي الكترونيك قدرت به نحوي زياد شده است كه مقالات متعددي در اين زمينه به چاپ رسيده است. روشهاي متنوعي در كنترل مبدل­هاي قدرت ارائه شده است كه از رايج­ترين روش­ها مي­توان به مدلاسيون بردار فضايي، مدلاسيون پهناي پالس و ... اشاره نمود. در اين پايان نامه از روش كنترل پيش­بين مبتني بر مدل براي كنترل كننده يك اينورتر منبع ولتاژ سه­فاز چهارساق استفاده شده است. روش پيشنهادي در اين پايان­نامه با اعمال قيد كليدزني در طراحي كنترل­كننده باعث كاهش فركانس كليدزني مي­گردد كه تلفات ناشي از كليدزني را كاهش مي­دهد در عين حال باعث بهبود عملكرد سيستم در توان­هاي بالا و كاهش هزينه نهايي ساخت مبدل مي­گردد همچنين با استفاده از روش پيشنهادي در حالت كنترل پيش­بين دو مرحله­اي مي­توان زمان نمونه برداري سيستم را افزايش داد. علاوه­بر­اين مي­توان به مقاوم بودن كنترل­كننده پيشنهادي در تغييرات امپدانس خط اشاره نمود كه اعوجاج هارمونيكي كل سيستم در محدوده قابل قبولي قرار مي­گيرد. كه به‌منظور بررسي عملكرد صحيح روش پيشنهادي حالت‌هاي متعادلي و نامتعادلي سيستم موردمطالعه، در محيط سيمولينك نرم‌افزار متلب شبيه‌سازي گرديده است. واژه‌هاي كليدي: كنترل پيش‌بين ، اينورتر، ، كاهش فركانس كليدزني، قيد كليدزني، امپدانس خط

  Abstract: Today, due to the limited fossil fuels, environmental pollution, the transition from this fuels to renewable energy is inevitable. Among the renewable energies, solar and wind energy have received more attention due to better accessibility and higher capacity. Wind turbines with vertical and horizontal axis are used to exploit the wind power, which are more commonly used with horizontal axis wind turbines due to higher power extraction. The generators used in these turbines are also divided into two categories: constant speed and variable speed. Variable speed generators are more commonly used due to lower mechanical stress and higher efficiency. Among variable speed generators, DFIG is particularly important because of its unique advantages. These features include four-zone Active and Reactive Power Control, optimum performance at variable wind speeds, lower converter costs and reduced power losses and more. Today, due to the special structure of wind generators and the way they are controlled and connected to the grid, as well as issues such as variable wind speeds and uncertainties, the use of these generators faces particular problems. These include power generation control, maximum power point tracking, optimum performance at voltage and current unbalanced conditions. The wind turbine studied in this study is a doubly feed induction generator (DFIG) in which the stator is directly connected to the grid and the rotor coil is powered by a frequency converter consisting of two AC-DC converters based on a two-way IGBT controller and a DC link. Rotor-side converter with variable frequency injector plays the role of compensator for mechanical frequency difference with grid frequency. The grid side converter function is control of DC link voltage and in some cases provide reactive power. In this study, the performance and control design of a doubly fed induction generator is first evaluated in balance and then the DFIG generator is analyzed while the grid voltage is in unbalanced state. In a doubly fed induction generator, the unbalanced grid voltage causes the stator current, the rotor current to the converter, the current to the converter, torque and flux to be unbalanced. In this study, the stator and rotor currents are balanced by separating the positive and negative components in the unbalanced state of the grid voltage and negative sequence compensation. In the next step, the voltage of point of common coupling will be unbalanced because of the interruption of one of the three-phase load phases, using the static synchronous compensator (STATCOM) with the Decoupled Double Synchronous Reference Frame method (DDSRF) will be balanced and stabilized. In this study, MATLAB simulator software, which is a powerful software in this field, was used to analyze the system and model under study. By comparing the waveforms of the stator current, rotor, grid side converter and PCC point voltage obtained from the proposed control scheme and comparing it with the absence of control on the system, it can be concluded that the proposed design can guarantee the performance of doubly fed induction generator in different conditions. key words: doubly fed induction generator – unbalance voltage - negative sequence – current of stator - static synchronous compensator -   decoupled double synchronous reference frame

در اين پايان نامه يك مدل جهت تامين انرژي مورد نياز يك خانه هوشمند، شامل انرژي الكتريكي و انرژي حرارتي ارائه شده است. خانه مورد نظر متشكل از واحدهاي توليدكننده انرژي ميكروتوربين، بويلر و توربين بادي مي باشد. ميكروتوربين مورد استفاده در اين خانه داراي قابليت توليد هم زمان برق و حرارت (CHP) است. هم چنين ذخيره كننده هاي الكتريكي و حرارتي جهت مديريت بهتر انرژي در نظر گرفته شده است. لازم به ذكر است خانه هوشمند مورد نظر داراي تبادل دو طرفه با شبكه توزيع انرژي الكتريكي مي­باشد. سوخت مصرفي ميكروتوربين و بويلر گاز طبيعي و وظيفه بويلر تامين كردن كمبود انرژي حرارتي لازم جهت تامين بار حرارتي خانه مي باشد. مدل ارائه شده به برنامه­ريزي انرژي الكتريكي و حرارتي خروجي واحدها و مقدار انرژي مبادله با شبكه بالادستي با هدف كاهش هزينه هاي تامين انرژي خانه و با ارضاي قيود مورد نظر از جمله قيد ميزان آلودگي مي­باشد. خانه مورد نظر با قابليت اجراي برنامه پاسخگويي بار با هدف مسطح نمودن پروفيل انرژي الكتريكي مصرفي خانه و كاهش هزينه هاي تامين انرژي در نظر گرفته شده است. نتايج شبيه سازي نشان داد كه مدل ارائه شده جهت تامين انرژي الكتريكي و حرارتي مورد نياز خانه، توانايي كمينه نمودن هزينه تامين انرژي الكتريكي و حرارتي خانه با در نظر قيد ميزان آلودگي و برنامه پاسخگويي بار را دارد. در اين پايان نامه، جهت كمينه نمودن مقيد هزينه تامين انرژي خانه، از الگوريتم بهينه سازي ازدحام ذرات (PSO) استفاده شده است.

  SRM motors have attracted considerable attention due to its low cost and robust structure, high efficiency, and the ability to track at variable and high speed and high ambient temperature. SRM engines are one of the oldest types of electric motors that were left out of the lack because of proper control systems, but today with modern semiconductor technology, SRM engines can be made cheap and even easier than induction motors, and will Compete with all other electric motors soon. One of the problems with this machine is the speed control complexity that is influenced by the effect of the voltage thresholds of each phase and the detection pulses which applied on phases but nowadays engineers are working to overcome the obstacles that cause these problems over time.

SRM motors have attracted considerable attention due to its low cost and robust structure, high efficiency, and the ability to track at variable and high speed and high ambient temperature. SRM engines are one of the oldest types of electric motors that were left out of the lack because of proper control systems, but today with modern semiconductor technology, SRM engines can be made cheap and even easier than induction motors, and will Compete with all other electric motors soon. using the sensor to detect the position of the rotor increases the price and complexity of the engine structure, and in addition, in the event of burning or dusting and the mass of each sensor and also noise on sensor cables which given the fact that it is used in industrial environments or electrical appliances, It is likely that this engine will not be welcomed, but in a sensorless method that uses feedback from different parts of the engine and using a microprocessor and writing complex codes to detect the position of the rotor and start the engine and take a long time It takes itself and needs much more science, but all of these happen just one time, and the engine's surroundings make it easier to control other engine parameters.

  Fossil fuels are declining as sources of human consumption over the years, and in addition to the greenhouse gas emissions that result from these fuels, they are damaging our planet. Renewable energies as a solution to reduce the adverse effects of reducing fosil energy reserves, resulting in an intensification of the global energy crisis as well as an increase in greenhouse gas emissions resulting in harm to the environment. In addition to using these resources, network planning should be done in such a way as to minimize the economic cost to the network. In this case, power plants with a higher fuel cost with less power and low fuel-efficient power plants enter the service with more power. This operation is performed according to load balancing equations and pseudo-security assertions, which is known as the optimal load distribution name. If the problem of optimal load transfer includes random input variables such as the power output of the wind power plant, the output of the problem will also be random, so this type of problem-solving optimal load transfer problem is called optimal load probability. In this paper, for the first time, the Cultural Algorithm (CA) is applied to solve the probable optimal power flow problem in the presence of wind power plants uncertainties and taking into account the power network constraints. The Cultural Algorithm is used as a general optimization method for nonlinear and non-convex functions and can substantially shift the target functions with respect to the problem constraints towards the optimal solutions. In this paper, various methods regarding to generation changes in the structure of the algorithm are also compared and investigated. In addition, the improvement methods of the proposed algorithm applied to limited input problems has been discussed and detailed, especially on optimal power flow problem concluding the uncertainties. The ability of the presented algorithm in optimizing the described problem for IEEE standard 30 and 57 buses test cases has been addressed and challenged using MATLAB software among the other well-known algorithms in this field.

بررسي قابليت اطمينان شبكه هوشمند با لحاظ نمودن خودترميمي شبكه در حضور منابع توليد پراكنده

  The photocatalytic CO2 reduction has attracted more attention owing to the increasing global energy crisis and environmental contamination. In this work, BaTiO3 nanoparticles decorated with Fe2O3 nanoparticles were successfully prepared by hydrothermal method for efficient visible-light photocatalytic CO2 reduction, and successfully characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), FT-IR spectroscopy, UV-visible and photoluminescence spectroscopy (PL) techniques. UV-visible and PL analyses showed the higher response of composites, in visible region and higher efficiency of charge separation, respectively. The FESEM illustrated the well crystalline particles of BaTiO3 and Fe2O3, and the BF31 (BaTiO3:Fe2O3 with 3:1 molar ratio) image shows a good dispersal of BaTiO3 and Fe2O3. Compared to bare BaTiO3, Fe2O3 and other different molar ratio composites, the BF31 composite photocatalysts exhibited strongest enhanced photocatalytic CO2 reduction activity under visible light irradiation. The photodegradation percentage of CO2 for BF31 composite could reach 22%, which was much higher than those of bare BaTiO3, Fe2O3 and other different molar ratio composite samples. The enhanced photocatalytic CO2 reduction activity could be attributed to the formation of heterojunction at the interface between BaTiO3 and Fe2O3 in the composite, which would facilitate the photo-generated electron-hole separation and thus improve the photocatalytic activity.

راه‌ها به منظور دسترسي يا حمل ونقل احداث مي‌گردند. نظر به اين كه شرايط محيطي همچون كوه، تپه، دره، تقاطع، تغيير مسير به نقاط موردنظر و ... در راه اعمال مي‌شود، بنابراين راه ديگر نمي‌تواند فقط يك مسير مستقيم باشد، بلكه به شكل‌هاي هندسي متفاوتي درمي‌آيد. به همين دليل است كه نياز به يك طرح هندسي مطلوب احساس مي‌شود. امروزه افزايش ايمني راه ها به يكي از معضلات مهم كشورهاي در حال توسعه در بخش حمل و نقل و اقتصاد تبديل شده است و از اين رو در سال هاي اخير تحقيقات قابل توجهي در سراسر دنيا براي درك ارتباط بين تعداد تصادفات، حجم ترافيك عبوري، مشخصات هندسي مسير و عوامل محيطي در قالب مدل هاي پيش بيني تعداد تصادفات انجام پذيرفته است. اين مدل ها ابزاري قوي در تحليل تصادفات محسوب مي‌گردند كه در شناسايي و تحليل نقاط حادثه خيز در جاده هاي برون شهري به كار گرفته مي شوند. استفاده از مدل هاي پيش بيني كه بر اساس روش هاي دقيق آماري و اطلاعات راه ها و تصادفات بدست مي‌آيند، نه تنها در ارزيابي اصلاحات هندسي و مديريتي راه موثر واقع مي شوند بلكه شناسايي نقاط حادثه خيز را آسان و قابل بررسي مي نمايد. كمربندي شهرستان ايلام همه ساله مسيري اصلي براي تردد زائران حسيني به سمت مرز مهران واقع شده كه بر اهميت مطالعات بر روي مسير كمربندي شرقي مي افزايد. در اين تحقيق تلاش شده است با استفاده از بانك اطلاعاتي شهرستان ايلام، داده‌ها جمع آوري و مدلي ارائه شود، تا ميزان تاثير پارامتر هاي موثر طرح هندسي و همچنين كاربري هاي اطراف مسير بر ايمني جاده هاي برون شهري بررسي شود. در كنار جاده ها زمين‌هايي كه وجود دارند با كاربري‌هاي متفاوت مي‌باشند كه تأثير آن بر ايمني بررسي خواهد شد. در اطراف جاده ها مي‌تواند مكان هاي متفاوت با كاربري‌هاي مختلف وجود داشته باشد كه باعث تعامل و رفت و آمد مراجعان مي شود. اين رفت و آمد مراجعين سبب بروز عواملي چون ترافيك شده كه با توجه به راه طراحي شده و ويژگي هاي طرح هندسي راه مي‌تواند سبب ايمن بودن طرح يا بروز تصادفات رانندگي شود كه بايد براي مسيرهاي خطرناك يا پرتردد تعابير مهندسي لازم را در نظر داشت. بدين منظور متغيرهاي تاثير گذار و وابسته كه ايمني جاده مي باشد جهت پردازش آناليزهاي لازم انتخاب خواهد شد و بررسي هاي لازم و شرح ارتباط ميان ايمني جاده يا متغير وابست? تحقيق حاضر با ويژگي هاي طرح هندسي راه و كاربري هاي زمين هاي اطراف جاده صورت مي‌پذيرد سپس در ادام? بررسي حاضر به ارائه مدلي با بسط موارد ايمني راه، كاربري اطراف جاده و طرح هندسي پرداخته خواهد شد بطوريكه بصورت موازن? سه پارامتر را دربرگيرد. سپس بر اساس آمارگيري و برداشت‌هاي ميداني در محورهاي كمربندي شرقي ايلام و تكميل اطلاعات لازم، مدل كاليبره و ارائه خواهد شد.  

تحليل تكيه گاه بتن آرمه اي ميراگرهاي ويسكوالاستيك متصل به ديافراگم طبقات

  The issue of   unit commitment is to determine the situation of switching on or off the available power generation units in a power grid. By solving this problem, the quantities of productive powers are determined economically, according to the existing constraints. One of the important criteria in solving the problem of orbiting unit commitment is to minimize the cost of electric power supply for the power system over a given time period. In recent years, the use of renewable energy for electrical energy has been given particular attention due to rising fossil fuel costs and also environmental problems caused by these fuels. On the other hand, , there are also some problems of the participation of these units in supplying demand for the network with the increased penetration of renewable energy sources in power systems. One of these problems is the uncertainty in the electrical energy produced by these units, and also the unavailability of these units in the hours of the day. The uncertain nature of the energy produced by renewable energy sources has led to a difference in the actual and projected output power of renewable unit commitment. Therefore, the combination of active units in planning in the circuit of the unit commitment in real time may be subject to changes that will remove the system from the performance at the optimal point. To overcome this problem, it is necessary to determine how the renewable energy sources participate in supplying the demanded load of network through the planning of unit commitment. Therefore, by reducing the uncertainty of the capacity of the production of renewable energy sources, the system can be brought closer to the optimal work point. Therefore, in order to compensate for the nature of periodic and incidence of renewable energy sources, electrical energy storage devices have been used in power systems. In fact, the purpose of using energy storage systems in power systems is to maximize the use of renewable energy sources. In this paper, the problem of the installation of unit commitment has been investigated, due to the many problems associated with the use of fossil fuels, with regard to the cost of pollution in the presence of renewable energy sources and energy storages. The MATLAB software, the Combination of the Genetic Algorithm and the Priority List Procedure with new use have been used to solve the problem in unit commitment. In this method, the initial population is produced in such a way that the supply and demand equivalence requirements and the minimum time down, the minimum time up of the units the constraints of the ramp rate, and the reduction of electrical power of units and the reserve of the spinining reserve erformed on the standard 10 units and 38 units. The results indicate that this process can help reduce the cost of the problem in the circuit of the unit commitment.

New modern world intensively needs high quality and reliable electricity energy. Distributed Generation (DG) resources are one of the best choices for electricity energy provision. Whereas use of distributed generation resources provides feasibility of implementation of hierarchical control on small grids alike big grids, electrical energy distribution grids that comprising distributed generation resources are known as Microgrids. Microgrids usually are used in grid connected mode but if fault occurs in grid or when improvement of load power’s quality is need, they can work in islanded mode. Because of presence of 1 phase loads and 1 phase resources such as solar cells, microgrids’s voltage aren’t balanced. Voltage unbalancing causes decrease of electrical energy’s quality, increase of losses and decrease of microgrids’s stability. So proposition of suitable control solution for unbalancing voltage compensation is very important. In this thesis we want to compensate voltage unbalancing in Point of Common Coupling (PCC) in presence of 1 phase unbalanced load for both grid connected and islanded modes because voltage unbalancing might causes diturbtion and makes problems for sensitive loads. For voltage unbalancing compensation usually two decoupled control loop are used for positive and negative sequences. This structure is known as Double Synchronous Reference Frame (DSRF). In this thesis for improvement of current and voltage DSRF controller’s performance and elimination of oscillations in unbalanced voltage condition, Decoupled Double Synchronous Reference Frame (DDSRF) has used. The method is in such a way that oscillation’s amplitude and phase is estimated and implemented to DSRF. So oscillating couple between positive and negative current control loops and between positive and negative voltage control loops are eliminated and it causes of unbalancing voltage of PCC in both grid connected and islanded modes.

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Power transformers are one of the most valuable equipment in power systems in which fault occurrence may cause severe damages and significant decrease of network reliability. Moreover, winding and terminal faults include more than 70% of occurred faults in power transformers. One of the various type of winding fault is inter-turn fault. As a rule, most of the protection systems do not detect the inter-turn fault at the beginning of occurrence. Therefore, this fault spreads to more turns and finally leads to main damages. There are different methods and algorithms to determine this kind of fault and each of them has particular advantages, disadvantages and uncertainties. In this thesis, the behavior of a Y-Y connection transformer during inter-turn fault has been investigated through simulation in Maxwell software and an online, fast, simple and also sensitive method is introduced based on the results and transformer equations. This method which is based on primary and secondary earth-fault current differential is capable to determine inter-turn fault (1% of entire winding) in various conditions such as full load, no load or even load unbalance. Two more common methods (Park Vector and negative sequence current) have also been simulated in order to compare to this method and the results are compared together. The introduced method in this thesis can be used to protect transformer in time of inter-turn fault.   

  A challenge of power transformers is mechanical faults occurred in windings, which may leave catastrophic effects in case of non-detection. Frequency response analysis, or transfer function method, is a powerful technique for monitoring power transformers, which can greatly help to increase the lifetime of the transformer and reliability in the power grid. A transformer may pass during severe short-circuit currents operation due to various power grid faults. One of the most serious problems with an in-service transformer is movement of its windings due to electromagnetic forces generated during short-circuit faults. Reduction of clamping pressure due to insulation aging can also cause winding movement and may result in an explosion. One of the methods for detecting the mechanical defects of the transformer is the frequency response analysis. Recent studies concentrated on the effects of various errors on the frequency response of the transformer. In order to study the effect of different deformation scenarios, transformer models have been developed. An accurate enough transformer model is required to study the various parameters on Frequency response analysis. Unfortunatly some of the parameters of the detailed model are frequency dependent. A detailed model is used to simulate transformer behavior especially in high frequency transients. This model was seen to be accurate enough to simulate frequency response of the transformer. Unfortunately some parameters of the transformer model are frequency dependent due to skin effect or proximity. Among this parameters the coil series resistance was seen to be more frequency dependent and in this thesis it has been shown that this factor affects different indices of the different transfer functions differently. Four transfer function used rather more in different papers and standards were derived to investigate the effect of frequency depended series resistance on them. Detailed transformer model parameters are derive from 3 dimentional transformer simulation in Maxwell software.

  The Electromagnetic Aircraft Launch System (EMALS) is being developed, electrical and electronic technologies, to replace the existing steam catapult on naval carriers. Recently, the double-sided linear launcher has attracted more and more attention from researchers. This paper presents utilizing the design and analysis of the Linear Hybrid Reluctance Motor (LHRM). This new motor is characterized by a stator formed by a combination of independent magnetic structures, each one composed of an electromagnet, the magnetic core with one or several coils wound on it, associated with a permanent magnet disposed between their poles. The rotor has the same configuration of a switched reluctance motor (SRM) without any coil, magnets, or squirrel cage. In order to improve the thrust characteristics of LHRM, the structural characteristics and magnetic field are analyzed. The initial design, the finite element analysis (FEA) is presented to obtain the magnetic cogging force and thrust force. Then Using FEA, the effects of the parameters on the thrust and thrust ripple waveforms is analyzed.

  analyzing THE SMART BUILDINGS ON THE LOSS REDUCTION AND IMPROVING THE VOLTAGE PROFILE APPLYING TLBO