Sharif Digital Repository

CHP (Combined Heat and Power) generates electricity and thermal energy simultaneously from input fuel. Since it has high energy efficiency and low installation time, it is an appropriate approach in energy management of residential complexes. In this project, stochastic programming based on Monte Carlo approach is used to handle uncertainties in the optimal sizing of CHP for residential complexes. Availability of CHP, boiler and AC bus as well as the electrical and thermal load forecast errors are considered as stochastic variables. Minimizing system total cost considering the probability of each scenario obtained from the scenario reduction algorithm is the objective function. The system... 

Using a combination of groundwater and surface water, is defined as each project planned by combining these two sources which, in most cases, will achieve greater benefits than the non-integrated. The benefit is a set of privileges that technically, economically and environmentally justify the project. One of the prevalent and effective problems of fertile and flat plains of Khuzestan province, especially the Evan plain, is lack of proper drainage of agricultural land downstream of dams and irrigation networks which are covered by. In this plain also, according to statistics from Piezometers, the groundwater level is rising. At the first, the aim of this study is to study the current... 

Nowadays, due to the increasing importance and penetration of microgrids, solving the microgrid optimal sizing problem has become more important. The current utility grid and conventional energy sources are mainly ac, however, increasing rate of the replacement of the ac load with dc load lead to a more efficient dc system. So choosing the optimal type of microgrid as a way to increase efficiency of these systems would be a serious issue. This thesis establishes a planning model which finds the optimal size and type of a microgrid to minimize total cost. Total cost includes investment, operation and reliability cost of the microgrid. Sizes of DGs, converters and transformer linking the... 

With increasing demand levels in recent years, transmission congestion is considered as one of the most important power system constraints. This limitation can result in higher operational costs and load curtailment. Furthermore, in power systems with high penetration of wind power, a significant amount of wind curtailment may occur due to congestion of transmission lines. Thus, in order to guarantee a reliable and economic operation of the power system, new transmission lines should be constructed with a rational plan. Very high investment costs are required for building new transmission lines to meet the growing demand. This fact as well as the other associated difficulties emphasize the... 

Fuel cell is a very attractive technology for clean electricity production and has a wide range of applications from industry to transportation and power generation. There are several issues that prevent the development of this technology widely. Rapid degradation of fuel cells during operation is one of them. Online monitoring of operational parameters in order to control and optimize the effective variables of power generation and life of the fuel cell considered as an important way to mitigate fuel cell’s degradation. In this research, a set of models were developed to calculate the voltage, current, corrosion, as well as the fuel cell system state variables instantaneously. Two robust... 

In this dissertation, the value of distribution network reconfiguration in presence of distributed generation is investigated. In the first step, a mathematical optimization model is devised to minimize daily network losses via applying hourly reconfigurations. The results show that the hourly reconfiguration reduces the losses. Then, sensitivity analyses on the renewable penetration, wind and load correlation, switching cost and wind power prediction are conducted and discussed. The switching cost analysis revealed that a great amount of loss reduction could be attained with a small number of switching operations. The worthiness of reconfiguration becomes more in systems with high... 

Microgrids will be key components of future smart grids that integrate distributed generation energy with local loads and units for greater efficiency. However, the uncertainty and intermittent nature of renewable energy products prevent the reliable operation of the micro-grids. On the other hand, the introduction of electric vehicles into the transportation industry can be both a challenge and an opportunity for the power grid. Using electric vehicle batteries as an energy storage system is a new work in the smart grid environment. Using an electric vehicle battery as a storage system makes it possible to create a grid with a lower operating cost because of the development of renewable... 

Risk management is the systematic application of management policies, procedures and processes related to risk analysis, assessment and control activities. Risk management is the process of documenting the final decisions made and identifying and applying criteria that can be used to bring risk to an acceptable level. Costs have been studied separately as less attention has been paid to the combination of these two factors. In this study, the combined effect of these two factors on projects in the first place and then on construction, operation and transfer projects has been investigated. The statistical population of the present study consists of 250 contractors and employers of... 

Sustainable energy supply and preservation of the environment have become the main motivations to integrate more renewable energy sources in electrical networks. However, with an increasing penetration of renewable energy sources in the modern electrical grids, new challenging issues arise regarding the power system planning, operation, control and protection. An important technical issue is the difficulty in achieving the frequency stability of these systems, as the renewables are often operated at the maximum power point, resulting in less generation units that provide reserve power. Moreover, the rotational inertia of the system is reduced due to the decoupling of the renewable energy...