Sharif Digital Repository

Fast charging stations are vital components for public acceptance of electric vehicle (EV). The stations are connected to the electric grid and can recharge an electric vehicle in less than 20. min. Charging station development is highly influenced by the government policy in allocating station development costs. This paper presents a Mixed-Integer Non-Linear (MINLP) optimization approach for optimal placing and sizing of the fast charging stations. The station development cost, EV energy loss, electric gird loss as well as the location of electric substations and urban roads are among the factors included in the proposed approach. Geographic information has been used to determine EV energy... 

Distributed generation (DG) corresponds to the application of small generating units which are the set up in distribution systems or near load centers. Utilization of DG influences various operational indices of the distribution feeders such as feeder loading, electrical losses and voltage profile. In addition, use of DG in its appropriate size is an essential tool to attain the DG maximum potential advantages. In this paper, an optimization method is proposed to determine the optimal size of DG in the distribution system. This method considers the system technical factors such as losses, voltage profile and loading of the primary distribution system feeders. The optimization process is... 

Although permanent magnet synchronous motors (PMSMs) are inherently of high efficiency, their efficiency is enormously dependent on their control strategy. The purpose of this paper is to improve the efficiency of PMSMs under a direct torque control (DTC) method. The main idea behind the proposed method is to predict a required small change of the statorflux amplitude at each sampling period to reduce the machine electrical loss before the change is applied. Accordingly, at every sampling time, a voltage vector is predicted and applied to the machine to change the flux amplitude in a xvay that the electrical loss decreases. The results of simulation show significant improvement in the... 

Two main sources for power dissipation in parallel buses are data transitions on each wire and coupling between adjacent wires. So far, many techniques have been proposed for reducing the self and coupling powers. Most of these methods utilize one (or more) control bit(s) to manage the behavior of data transitions on the parallel bus. In this paper, we propose a new coding scheme, referred to as GPH, to reduce power dissipation of these control bits. GPH coding scheme employs partitioned Bus Invert and Odd Even Bus-Invert coding techniques. This method benefits from Particle Swarm Optimization (PSO) algorithm to efficiently partition the bus. In order to reduce self and coupling powers of... 

Importance of power dissipation in NoCs, along with power reduction capability of on-chip optical interconnects, offers optical network-on-chip as a new technology solution for on-chip interconnects. In this paper, we extract analytical models for data transmission delay, power consumption, and energy dissipation of optical and traditional NoCs. Utilizing extracted models, we compare optical NoC with electrical one and calculate lower bound limit on the optical link length below which optical on-chip network loses its efficiency. Based on this constraint, we propose a novel hierarchical on-chip network architecture, named as H2NoC, which benefits from optical transmissions in large scale... 

In this paper, n-tier methodology is developed to design multilevel interconnect architecture of macrocells using single-wall carbon nanotube (SWCNT) bundles. Upper limit of low-bias voltage of SWCNT bundle interconnects is derived and its dependence on temperature, SWCNTs' diameter, and interconnect length is studied. Possibility of using SWCNT bundles as local interconnects at 7.5-nm technology node is discussed, and it is shown that SWCNT bundles with 1 nm diameter cannot be used at the first interconnect metal level. Using Cu and SWCNT bundles, multilevel interconnect architecture of a 7.5-nm ASIC macrocell is designed which reduces the number of metal levels by 27% and power dissipation... 

This paper presents an improved stochastic simulation method for calculating current dependent energy losses in distribution networks. The method is based on power load curves and integrates the stochastic nature of the load curves with power and voltage covariance matrices. The method reduces calculation effort using the factor analysis of covariance matrices and provides a few quantities needed to calculate energy losses. The method has no limitation for network configuration and gives accurate results several times faster than other existing methods. Therefore, it is appropriate for considering losses in optimization and decision making purposes in operating and planning of distribution... 

High-quality guided wave devices are key components in integrated millimeter-wave circuits. In this paper, we propose mm-wave planar dielectric waveguides based on thin, anisotropic artificial dielectric layers with very high in-plane permittivity. Waves propagating on such films are surface waves whose field exponentially decays outside the film in the vertical direction, similar to waveguides commonly used in integrated optics. The very high in-plane permittivity of the artificial dielectric layers leads to strong field confinement, and allows the implementation of relatively thin waveguides. This fact, together with the planar structure of these devices, make them highly suitable for... 

This paper presents a new framework for planning studies of modern distribution networks. Presence of electric vehicles (EVs) and various technologies of distributed generation (DG) technologies are considered in the studies as two upcoming events of the future systems. In this regard, place and capacity of DG units along with the reinforcement of distribution lines are determined running a multi-objective (MO) optimization algorithm. Total losses of the distribution network along with annualized cost of expansion plans including investment, operation and maintenance costs are introduced as the main criteria which should be optimized in the proposed framework. An effective Posteriori... 

In this paper, design and prototyping of two-speed capacitor-run single-phase axial-flux induction motor (AFIM) for direct-drive applications is presented. The proposed structure has single stator-single rotor configuration with high magnetic pull between the stator and rotor, which may compel rotor to lock. Although the most efficient method to overcome this problem is using a second rotor or stator in the mirror with the first one, it is not applicable in low-cost applications. So, in this paper, two new and fast construction techniques are proposed to fabricate an AFIM with extra low air-gap length and minimum cost. Beside design and optimization process, a thermal equivalent circuit... 

Aerosol measurement is used in a variety of fields such as nanotechnology, materials science, pollution monitoring, air quality measurements, combustion and engine exhaust analysis, inhalation toxicology, and medical studies. One of the most prevalent methods for aerosol measurement is to use electrical mobility. An electrical mobility spectrometer (EMS) is used to measure aerosol particles size distribution ranging from 10-1000 nanometers, under the influence of an electric field. The accuracy of this distribution is influenced by flow conditions, the geometry of the EMS, the electric field, and the number of electrode rings. In this work, a multi-channel EMS is studied using computational... 

Network on chip (NoC) has been proposed as an appropriate solution for today’s on-chip communication challenges. Power dissipation has become a key factor in the NoCs because of their shrinking sizes. In this paper, we propose a new encoding approach aimed at power reduction by decreasing the number of switching activities on the buses. This approach assigns the symbols to data word in such a way that the more frequent words are sent by less power consumption. This algorithm dedicates the symbols with less ones to high probability data and uses transition signaling to transmit data. The proposed method, unlike the existing low power encoding, does not rely on spatial redundancy and keeps the... 

In a deregulated environment of power distribution industry, a comprehensive economic evaluation for the implementation of distribution automation (DA) systems is inevitable. Using the presented methodology in this paper and system dynamics approach, it is efficiently possible to deal with variation of the economic parameters such as the interest rate, inflation rate, energy supply cost, load growth, etc. In this paper, economic short-run and long-run impacts of DA systems are evaluated from utility point of view. Also economic benefits from customers' point of view are analyzed. A practical pricing strategy for maximizing the utility profit is suggested depending on the underlying market... 

An adaptive approach for distribution system reconfiguration and charging management of plug-in electric vehicles (PEV) is presented in this study. A stochastic model predictive control is applied to stochastically, adaptively, and dynamically reconfigure the system, manage the incidental charging pattern of PEVs, and deal with the variable and uncertain power of renewable energy sources. The objective function of problem is minimizing daily operation cost of system. Herein, the geography of area is considered and the behavior of PEVs' drivers (based on their income level) is modeled with respect to the value of incentive and their hourly distance from each charging station. It is shown that... 

To achieve economic stability, distribution Company as an economic institution should be managed by various processes. In this way, knowledge of different processes is the first step. Furthermore, expectations, outputs, requirement data, and sub-processes should be extracted and determined. Accordingly, to assign the performance responsibility of each process, the decision making points must be introduced and, the deviation or change in set-points should be investigated into processes. Also, the performance of processes could be monitored by introducing of the sub-indictors. In this study, a practical method is presented for monitoring of reliability and power loss indices from viewpoint... 

This paper investigates three different strategies for centralized charging/discharging management of electric vehicles, their features and the impacts on technical performance of distribution systems. Three goals of load factor maximization, load variance reduction and energy loss minimization are chosen as the main technical factors need to be optimized in the proposed electric vehicles charging/discharging management strategies. In this regard, at first, the mathematical model of these strategies for both cases of with/without vehicle-to-grid (V2G) programs are extracted. Then, solving procedure of the attained optimization problems with different optimization methods are explained. These... 

This paper investigates three different strategies for centralized charging/discharging management of electric vehicles, their features and the impacts on technical performance of distribution systems. Three goals of load factor maximization, load variance reduction and energy loss minimization are chosen as the main technical factors need to be optimized in the proposed electric vehicles charging/discharging management strategies. In this regard, at first, the mathematical model of these strategies for both cases of with/without vehicleto- grid (V2G) programs are extracted. Then, solving procedure of the attained optimization problems with different optimization methods are explained. These... 

Fast-charging stations are connected to the electric grid and can fully charge an electric vehicle (EV) in less than half an hour. The capacity and location of the charging stations bring the costs to the electric grid operator, as well as to the station owner and EV user. A zonal approach has been proposed in this paper to determine the optimal place and capacity of fast-charging stations. Station development cost and the expected costs incurred by the EV user and the grid operator due to EV charging have also been included in the proposed approach. The geographic characteristics associated with the electric substations, urban roads, and city zones have also been considered in the proposed... 

An adaptive approach for distribution system reconfiguration and charging management of plug-in electric vehicles (PEV) is presented in this study. A stochastic model predictive control is applied to stochastically, adaptively, and dynamically reconfigure the system, manage the incidental charging pattern of PEVs, and deal with the variable and uncertain power of renewable energy sources. The objective function of problem is minimizing daily operation cost of system. Herein, the geography of area is considered and the behavior of PEVs' drivers (based on their income level) is modeled with respect to the value of incentive and their hourly distance from each charging station. It is shown that... 

In this paper, advantages of energy-efficient motors over standard-motors in terms of electrical energy saving and demand reduction in a tire-rubber factory are thoroughly evaluated. Energy-efficient motors reduce losses because of their better design, materials, and manufacturing. These motors are 2 to 8% more efficient than standard ones. Lengthening the core and using lower-electrical-loss steel, thinner stator laminations, and more copper in the windings reduce electrical losses. Because a motor consumes energy worth 4 to 10 times its own cost each year, energy-efficient motors often make economic sense in a wide variety of applications. At the end of this study, the amount of energy...