Sharif Digital Repository

This chapter proposes a methodology for optimal dispatch of bilateral electricity contracts, which may endanger the system voltage stability in light of short-term operational planning of a deregulated power system. In this framework the value that each owner of a transaction is willing to pay reflects how much the electricity contract is important to be implemented physically. The proposed model dispatches optimally the bilateral transactions regarding the prices offered by owners of bilateral contracts for reactive power and transmission capacity utilization in one hand and, the total operational costs of reactive power resources in the other hand. The model also includes the limits... 

This paper proposes a methodology for optimal dispatch of bilateral electricity contracts, which may endanger the system voltage stability in light of short-term operational planning of a deregulated power system. In this framework the value that each owner of a transaction is willing to pay will reflect how much the electricity contract is important to be implemented physically. The proposed model dispatches optimally the bilateral transactions regarding the prices offered by owners of bilateral contracts for reactive power and transmission capacity utilization in one hand and, the total operational costs of reactive power resources in the other hand. The model also includes the limits... 

A new method has been employed in this research that optimizes a power generation system by maximizing the first and second law efficiencies and minimizing the entropy generation. Mass flow rates of pollutants and related external social cost of air pollution have been considered in estimating the electricity production cost. The effects of regenerative and CHP heat exchangers on power production, efficiencies, and production cost have been evaluated. The results show that a single regenerative heat exchanger lowers NOx, CO, and CO 2 emissions by 15%, 40%, and 0.4%, respectively, and decreases the electricity production cost by nearly 18%. A single CHP heat exchanger has little influence on... 

Human detection is one of the hard problems in object detection field. There are many challenges like variation in human pose, different clothes, non-uniform illumination, cluttered background and occlusion which make this problem much harder than other object detection problems. Defining good features, which can be robust to this wide range of variations, is still an open issue in this field. To overcome this challenge, in this paper we proposed a new set of hybrid features. We combined the Histogram of Oriented Gradient (HOG) with the new features called Histogram of Small Edges (HOSE) which is introduced in this paper. These two kinds of features have two different approaches for... 

Machine learning algorithms often suffer from good generalization in testing domains especially when the training (source) and test (target) domains do not have similar distributions. To address this problem, several domain adaptation techniques have been proposed to improve the performance of the learning algorithms when they face accuracy degradation caused by the domain shift problem. In this paper, we focus on the non-homogeneous distributed target domains and propose a new latent subdomain discovery model to divide the target domain into subdomains while adapting them. It is expected that applying adaptation on subdomains increase the rate of detection in comparing with the situation... 

This paper presents an Artificial Neural Network (ANN)-based modeling technique for prediction of outlet temperature, pressure and mass flow rate of gas turbine combustor. Results obtained by present modeling were compared with those obtained by experiment. The results showed the effectiveness and capability of the proposed modeling technique with reasonable accuracies of about 95 percent. This paper describes a nonlinear SVFAC (State Vector Feedback Adaptive Control) controller scheme for gas turbine combustor. In order to achieve the satisfied control performance, we have to consider the effect of nonlinear factors contained in controller. The controller is adaptively trained to force the... 

In this paper, the impact of demand response programs (DRPs) on reliability improvement of the restructured power systems is quantified. In this regard, the demand response (DR) model which treats consistently the main characteristics of the demand curve is developed for modeling. In proposed model, some penalties for customers in case of no responding to load reduction and incentives for customers who respond to reducing their loads are considered. In order to make analytical evaluation of the reliability, a mixed integer DCOPF is proposed by which load curtailments and generation re-dispatches for each contingency state are determined. Both transmission and generation failures are... 

Passive islanding detection schemes are more used in utilities due to their low costs and less harmonic problems although having larger Non Detection Zones (NDZ) relative to other schemes. Passive system measurements at the point of common coupling (PCC) are the basis of this scheme. A new approach in passive techniques is the use of intelligent based methods in data-mining to classify the system parameters which affect the islanding detection. As a result, by finding an efficient and robust data-mining algorithm, the passive schemes problem, which is their relatively large NDZ, will be minimized. In this paper, massive measurements are collected by simulation of IEEE standard distribution... 

Islanding detection methods are divided into three main groups as remote, active and passive. Although passive schemes have larger Non Detection Zones (NDZ) relative to other schemes, they are more used in utilities due to their low costs and less PQ problems than other schemes. Passive Schemes are based on the measurements of passive system parameters. These parameters are measured at the point of common coupling (PCC). A new approach in passive techniques is the use of data-mining to classify the system parameters. In this paper, massive indices are collected by simulation of a practical distribution system in PSCAD/EMTP environment. These indices include voltage, frequency, current,... 

In this paper a new algorithm for allocating energy and determining the optimum amount of network active power reserve capacity and the share of generating units and demand side contribution in providing reserve capacity requirements for day-ahead market is presented. In the proposed method, the optimum amount of reserve requirement is determined based on network security set by operator. In this regard, Expected Load Not Supplied (ELNS) is used to evaluate system security in each hour. The proposed method has been implemented over the IEEE 24-bus test system and the results are compared with a deterministic security approach, which considers certain and fixed amount of reserve capacity in... 

This paper presents and utilizes an Improved Particle Swarm Optimization algorithm (IPSO) for reactive power management in restructured power systems. Reactive power procurement is modeled as a Security Constraint Optimal Power Flow (SCOPF), which incorporates a voltage stability problem. This is a major concern in power system control and operation. The model attempts to minimize the cost of reactive power procurement and energy losses as a main objective, while the technical criteria and voltage stability margin, especially, are treated as soft constraints. From a mathematical point of view, the reactive power market can be expressed as a nonlinear non-convex optimization problem with... 

The composition and topology of metal-organic frameworks (MOFs) are exceptionally tailorable; moreover, they are extremely porous and represent an excellent Brunauer–Emmett–Teller (BET) surface area (≈3000–6000 m2·g−1). Nanoscale MOFs (NMOFs), as cargo nanocarriers, have increasingly attracted the attention of scientists and biotechnologists during the past decade, in parallel with the evolution in the use of porous nanomaterials in biomedicine. Compared to other nanoparticle-based delivery systems, such as porous nanosilica, nanomicelles, and dendrimer-encapsulated nanoparticles, NMOFs are more flexible, have a higher biodegradability potential, and can be more easily functionalized to meet... 

This research proposes a new method for optimisation of a power generation system based on exergy fuel cost and external social cost of air pollution. A thermodynamic model is provided to estimate the outlet mass flow rates of CO2, CO, NO and NO2 for a gas turbine based on maximising the first and second law efficiencies and minimising the objective function. Results show that inclusion of the external social cost of air pollution increases the optimum excess air ratio if temperature constraint due to metallurgical consideration is disregarded. Otherwise external social cost of air pollution is independent of optimised conditions  

In this paper, a novel reinforcement learning method inspired by the way humans learn from others is presented. This method is developed based on cellular learning automata featuring a modular design and cooperation techniques. The modular design brings flexibility, reusability and applicability in a wide range of problems to the method. This paper focuses on analyzing sensitivity of the method's parameters and the applicability in optimization problems. Results of the experiments justify that the new method outperforms similar ones because of employing knowledge sharing technique, reasonable exploration logic, and learning rules based on the action trajectory  

Doubly-fed induction generator (DFIG) is the most commonly used technology for wind power generation due to the variable speed performance, decoupled control of active and reactive powers, and high efficiency. However, the DFIG originally cannot participate in damping of power system oscillations since it is not synchronously connected to the power system. This paper proposes an optimal and robust additional damping controller for the DFIG wind turbine to contribute it to damp power system oscillations. It is a fuzzy logic controller that its parameters are optimally tuned using the genetic algorithm (GA). The proposed controller modifies the DFIG active power output by using feedback from... 

Exploring efficient chemotherapy would benefit from a deeper understanding of the tumor microenvironment (TME) and its role in tumor progression. As in vivo experimental methods are unable to isolate or control individual factors of the TME, and in vitro models often cannot include all the contributing factors, some questions are best addressed with mathematical models of systems biology. In this study, we establish a multi-scale mathematical model of the TME to simulate three-dimensional tumor growth and angiogenesis and then implement the model for an array of chemotherapy approaches to elucidate the effect of TME conditions and drug scheduling on controlling tumor progression. The... 

Under voltage load shedding (UVLS) is one of the most powerful countermeasure and somehow an economical solution to sustain voltage stability especially for double or severe contingencies in power systems. In this paper the concept of dynamic security-constrained OPF is employed to develop a model for optimal UVLS. Considering dynamic voltage security, the presented model attempts to provide sufficient voltage stability margin for post contingency condition. This is done by means of interruption some portion of loads at minimum cost. The voltage stability margin, which is measured as a MW distance to the collapse point, is incorporated into the power flow equations. Although some powerful... 

Suspension flow has an important role in various applications such as paint, material and pharmaceutical industries. Settling is considered as a resisting phenomenon in the processes dealing with suspensions. Using nanoparticles as an additive to micro-particulates has been studied in limited studies. This work presents an experimental investigation to assess the effectiveness of nanoparticles in reduction of suspension settling. Microscopic imaging and transmission measurement were used to analyze the stability factors in a container. Transmission analysis revealed that presence of nanoparticles in the suspension, decreased the sedimentation rate. Microscopy showed that the settling rate... 

Due to the wide usage of rotary equipment and the necessity of their testing for maintenance and repair, test rigs have become necessary. The mechanical closed-loop test rig developed in Sharif University of Technology branch of ACECR (Academic Centre of Education, Culture and Research) is a test rig with low energy losses that is suitable for testing high power gearboxes such as aerospace or wind turbine gearboxes. It can be loaded up to 489Hp at a maximum speed of 3000 rpm, and the test components can be tested in different testing conditions including a variety of torques and speeds. This paper describes the preliminary, conceptual, and detailed design, steps including frame work design,...