Sharif Digital Repository

Concerns like fuel cost, pollution and global warming has made it necessary to look for new energy solutions. Renewable and alternative energies have proven themselves to be helpful in this matter. Renewable energy(RE) is the energy that comes from natural resources such as sunlight, wind, rain, tides, waves and geothermal heat, which are naturally replenished at a constant rate. Renewable energies are environmentally friendly, not cheap at the beginning but naturally available in a constant rate and wide spread, unlike fossil fuels that are localized in the limited places. In this thesis in order to generate environmental friendly power we consider two renewable energy resources: wind and... 

Advanced control techniques are required to achieve a cost-effective and reliable use of the wind power generation. The wind turbines are generally controlled based on two control objectives: the turbine protection and the generation of acceptable power for the utility grid. These objectives are achieved if the control inputs are applied based on appropriate control logics. In this work, a nonlinear multivariable model of the wind turbine with a DFIG generator is considered. The rotor speed and the d-axis rotor current (as the control outputs) are controlled via manipulation of the two generator voltages (as the control inputs) in low wind velocity condition. For high wind velocity, the... 

Nowadays, modern life needs energy resources. In the last few centuries, countries have focused on the use of fossil fuels. However, excessive use of fossil fuels, such as oil and coal, has resulted in enormous environmental hazards. Global warming and air pollution are the most visible manifestations of these hazards. In recent years, energy researchers have been looking for alternative sources. The result of this approach is to pay attention to clean and renewable resources such as wind energy.Wind turbines are used to generate electrical energy out of wind. Among the different types, floating offshore wind turbines have been mostly considered because of various benefits. However, they... 

Vibrations in HAWT reduce their efficiency and increase maintenance costs. In this paper, the blade edgewise vibrations are reduced by using several actuators in different parts of the wind turbine blade and optimization of the number and locations of actuators. The wind turbine blade dynamic behavior is investigated by using dynamic modeling. The actuators are trusses that are located inside each blade and apply control force to different parts of the blade. Active control force is applied to reduce edgewise vibrations. The designed controller is applied and simulated on NREL 5MW wind turbine. By applying the controller, the edgewise vibrations of wind turbine blades are significantly... 

Energy production from fossil fuels such as oil and gas is one of the non-renewable energies, which causes many environmental problems such as global warming and environmental pollution. The existence of these problems has led to agreements such as the Glasgow Environmental Agreement, which obligates governments to apply methods to reduce the production of greenhouse gases, which include reducing the consumption of fossil fuels and increasing the use of renewable energy. Sea wave energy is one of the renewable energies that can be used to generate electricity. In the seas of Iran, including the Caspian Sea, Persian Gulf and Oman, there are sources of wave energy that can be used and are... 

In recent years, and with the development of information technology in various aspects of life, the growth of energy consumption in this sector has accelerated. With the advent of cloud computing and the development of its users, data centers have become one of the largest consumers of energy in the world. Adverse effects of fossil fuel consumption on the one hand and the global energy crisis as a limiting factor for development, on the other hand, have doubled the importance of managing the issue and reducing energy consumption in this sector. The two main energy-related concerns in data center construction are clean energy and energy management. The use of new energy and natural facilities... 

Currently, cryptocurrencies have attained a significant role in the financial transactions of the world, especially due to their peer-to-peer and decentralized characteristics, resulting in the elimination of intermediary oversight entities. In the cryptocurrency network, transaction security is ensured through devices known as cryptocurrency miners. People place their cryptocurrency mining devices at the disposal of the cryptocurrency network and, depending on their device’s processing power and capacity, receive rewards in the form of cryptocurrencies. Given the complexity of cryptocurrency networks, regular devices lack the ability to mine cryptocurrencies, necessitating high processing... 

Power distribution systems are experiencing restructuring owning to the increasing trend of integrating renewable energy sources as well as privatization in the network. In this regard, the dependence of power generation by renewable energy sources on meteorological characteristics would challenge the conventional procedures of operating the system. Respectively, while the expansion of renewable energy sources would facilitate supplying the demand loads locally; the issues associated with the uncertainty and variability of power generation by these units should be addressed in future operational schemes of distribution systems. This condition has resulted in the development of the... 

In recent years, the penetration of renewable energy sources (RESs) in the distribution networks has faced their operation with new problems. Therefore, many studies have been conducted in this field to effectively operate distribution networks by introducing multi-microgrid (MG) structures, decentralized management methods, and the concept of transactive energy. In this regard, in this thesis, a decentralized structure based on the transactive energy is presented for optimal management of the distribution network using the alternating direction method of multipliers (ADMM) with taking the technical limitations into account. As a result, MGs will be able to exchange energy directly with... 

The most important challenge in microgrids is the coordination of distributed energy resources (DERs), due to the existence of several DERs with fugacious characteristics. Also, energy management in the microgrid is very important because there may be conflicting needs or poor communication between different elements of the microgrid. In this work, a robust frame associated with a quantum version of the Teaching-Learning-Based Optimization (quantum TLBO) algorithm is proposed for the first time to the microgrid optimal energy management problem. Uncertainties in the load and in the output power of renewable energy sources are modeled using robust optimization (RO). The operation cost of the... 

In recent years, the high energy consumption of blockchain technology has led to the creation of major problems such as more greenhouse gas emissions and additional pressure on the power grid. In this regard, the emerging technology of flow batteries for large-scale electricity storage might be a suitable choice to overcome both problems. In this research, a novel interdisciplinary methodology has been developed to optimize the flow battery design in different scenarios of energy systems with blockchain mining electricity demand. In this methodology, a new electrochemical model was developed for the vanadium redox flow battery with a no-mixing design, and its results were validated on... 

Providing fresh water for domestic and agricultural purposes has become one of the most pressing issues of the present century. Due to the dependency of conventional desalination on fossil fuels, these methods are associated with carbon dioxide and other greenhouse gas emissions. Therefore, renewable energy-based desalination systems have come to the fore. This study scrutinizes the performance of the solar Humidification-Dehumidification (HDH) desalination systems with subsurface condensers. In this system, solar energy evaporates water, and subsurface condensers condense water vapor into fresh water. Therefore, this system uses two renewable solar and geothermal energy. Due to the lack of... 

According to the Government policy in order to make targeted subsidies and apply it on various sectors in the industrial, commercial, agricultural, household and etc. changes in the energy supply needed resources in this section are required to appear. The agriculture sector is one of the most important parts of the food production is the production of security and health product. In this regard, the production of greenhouse products in terms of the use of high yielding varieties, production of the off-season, better control factors in production and reduce water consumption has increased drastically. The main source of supply in the internal energy of the greenhouse heating is mainly fossil... 

Considering the continuous growth of renewable energy sources in electric grids, the importance of utilizing simple, generic, and upgradable models for different network stability studies is increasing. In recent years, generic and standard wind turbine models for transient and short-term frequency and voltage stability studies have been developed. In this regard, researchers are still working on promotion of the generic models, especially to expand them for unbalanced transient studies, improve the transient response, and include inertia response. In this thesis, different methods for generic modeling of wind turbines are surveyed and the development procedure of WECC and IEC generic model... 

In recent years, energy storage systems have received widespread attention from researchers to increase the reliability of the power grid. These systems have different types that compressed air system is of special importance due to its high stored energy and long life. In this system, the surplus of electricity generated from renewable energy sources or grid electricity at low power consumption is compressed and stored in a tank. When there is a need for power consumption or peak power consumption, compressed air will generate electricity by passing through the turbine and will help the network. Large-scale type of the system requires special geographical location for air storage; for this... 

Wind energy is one of the fastest-growing renewable energy sources around the world. Nowadays, the use of offshore wind turbines has increased due to the high and uniform wind at sea, as well as resolving environmental issues such as making noise and sound pollution. Advances in wind energy technology has been effective in wind turbine control systems. Because the offshore wind turbines are affected by the turbulent wind and wave profiles, the control system should be designed to increase the output power quality, as well as alleviating the mechanical loads on different parts of the turbine. In this research, multiple model predictive control method is used to control offshore wind turbines,... 

Through the last decades, due to environmental issues and to confine CO2 emission and also dependency to the fossil fuels, renewable energy resources has been developed. It’s been expected up to 2035, the renewable energy resources will be scaled three times and among those resources, the wind energy will stand prominently. Out of this king of renewable resource, the horizontal wind turbine has been subjected in this research. The focus of is to design the controller in third of a 2 MW turbine operation by which stable rotor speed and nominal output power to be attained. Besides, to enhance the accuracy of the wind turbine profiles, the TURBSIM software (At the National Renewable Energy... 

By entering the concepts of transactive energy systems, microgrids and peer-to-peer networks into the local energy market, it has made it possible to implement local energy market in the microgrids more than ever. In transactive energy systems, with the elimination of the intermediate entity, exchanges take place directly between the different parts of the system, which results in increased system flexibility and reduced system costs. In this study, by applying blockchains in local energy market and in micro-grids and transactive energy systems, a framework is proposed to implement local energy market in an energy micro-grid based on blockchain. By using blockchain features and structure,... 

The penetration of renewable energies in generation section of power systems caused many issues and challenges for planners, operators and decision makers. One significant challenge is the uncertainty and variability of this type of generation, which must be properly covered; otherwise it would lead to wide load and supply curtailments. In this regard, some system operators introduced a new product, named Flexible Ramping Product (FRP) to their markets. FRP is the ramp capability of market participants which is reserved to cover the uncertainty and variability of net load (load minus intermittent supply) at next market time-interval of real-time market. With this in mind, the energy storage... 

Solar panels are still rather expensive equipments. At current electricity prices, it takes several years to return the investment made to install them in a household. Smarter use of their produced energy can help reduce this break-even time, and hence, would motivate more households to be willing to install and use them which would finally result in a more sustainable society with less reliance on fossil fuels. Electricity prices usually differ at different times of day with the common, but unfortunate, property that the price is maximized at evenings when the solar energy production is minimal or non-existent while at the peak production of the solar panels, i.e., around noon, the price is...