Sharif Digital Repository

Hardening and operational measures in electrical distribution systems (EDSs) aim at improving the resilience of EDS in case of natural disasters. This paper proposes a novel two-stage framework for establishing optimal restoration paths for supplying critical loads (CLs) in the aftermath of a natural disaster that will improve the resilience of EDSs. To this end, in the first stage, an algorithm is introduced to find all possible candidate paths between available distributed energy resources (DERs) and CLs, the output of which is applied to the second stage, as the inputs. Subsequently, in the second stage, the problem of finding the optimal restoration paths is modeled as a mixed integer... 

This article presents a new method for determination of meshing stiffness of the gear teeth using three dimensional analysis of tooth stiffness. The teeth are treated as explicit capacitive fields and their compliance matrix is determined by considering virtual interconnected springs located at defined nodes on tooth profile. The stiffness of any arbitrary point on the profile can then be determined as a linear function of neighboring nodes stiffness. The results of this analysis help in determination of load distribution for a pair of meshing gears under real operation conditions where deflections and misalignments are inevitable. Copyright © 2005 by ASME  

Despite the economic and environmental advantages of plug-in hybrid electric vehicles (PHEVs), the increased utilization of PHEVs brings up new concerns for power distribution system decision makers. Impacts of PHEVs on distribution networks, although have been proven to be noticeable, have not been thoroughly investigated for future years. In this paper, a comprehensive model is proposed to study the PHEV impacts on residential distribution systems. In so doing, PHEV fundamental characteristics, i.e., PHEV battery capacity, PHEV state of charge (SOC), and PHEV energy consumption in daily trips, are accurately modeled. As some of these effective characteristics depend on vehicle owner's... 

Design and development of fault diagnosis schemes (FDS) for electric power distribution systems are major steps in realizing the self-healing function of a smart distribution grid. The application of the FDS in the electric power distribution systems is mainly aimed at precise detecting and locating of the deteriorated components, thereby enhancing the quality and reliability of the electric power delivered to the customers. The impacts of two types of the FDS on distribution system reliability are compared and presented in this paper. The first type is a representative of the FDS which diagnoses the deteriorated components after their failing. However, the second type is a representative of... 

Due to the important role that distribution systems play in quality of power delivered to the customers, there has always been a great deal of interest in investigating different methods of efficiency enhancement for these networks. Two of these methods are Feeder Reconfiguration (FR) and Capacitor Allocation (CA); both have been widely employed to reduce losses and improve several other operational characteristics in electrical power distribution systems. As in FR process the topology of the network changes, it is necessary to change some previous settings; for instance: the capacity of capacitor banks in service in each bus, after each reconfiguration process. This is due to the fact that... 

With the expansion of electricity networks, increasing operational complexities, improved knowledge of the system operators, all with the subsidies elimination in some countries such as Iran and experiencing the real price of electricity by then, it necessitates a more reliable power to be delivered to the system customers. Power system automation is regarded as an efficient solution and the effective key to this problem. However, the great number of substations in power distribution systems has led to the fact that it is neither feasible nor economic to automate all of them. This calls for a comprehensive scheme on the placement of the distribution substations to be automated. In this... 

Design and development of fault diagnosis schemes (FDS) for electric power distribution systems are major steps in realizing the self-healing function of a smart distribution grid. The application of the FDS in the electric power distribution systems is mainly aimed at precise detecting and locating of the deteriorated components, thereby enhancing the quality and reliability of the electric power delivered to the customers. The impacts of two types of the FDS on distribution system reliability are compared and presented in this paper. The first type is a representative of the FDS which diagnoses the deteriorated components after their failing. However, the second type is a representative of... 

The aim of this two-part paper is to present a comprehensive reliability-centerd maintenance framework tailored to power distribution systems. The first paper discusses the fundamental concepts, presents the developed algorithm, and introduces the required mathematical formulations. This second paper is focused on the application of the proposed methodology on a real distribution system. Considerable effort is devoted to examine the proposed method in a step-by-step manner to clarify the implementation procedure. The required data for the procedure are taken from available references and follow reasonable technical assumptions. Practical aspects are incorporated, and the results obtained are... 

Existing real-time pricing (RTP) schemes charge the whole customer's consumption at one highly volatile time varying price, which, in turn, imposes financial risk to participating customers. This paper presents a two-part RTP scheme aiming at efficient distribution system operation while mitigating customers' risk level imposed by volatile RTP prices. Our proposed RTP scheme offers two different RTP price signals. The first RTP price signal is used to charge customer's consumption up to its customer baseline load (CBL) which presents customer's consumption in the absence of RTP signals. The second RTP price signal is announced a day ahead of the actual operation, and can be updated in real... 

Trying to find the most efficient and cost-effective decisions on the maintenance of different component types in power distribution systems is an increasingly challenging concern largely driven by the current financial constraints in distribution utilities worldwide. In regard to deal with this challenge, the paper presents a practical application of the Delphi method and the Modified Analytical Hierarchical Process (MAHP) that can be used to find the most critical component types of the system in order to assist in accordingly allocating the available maintenance budget. The proposed approach involves the experience and knowledge held by experts and the historical empirical performance... 

This paper describes how Enexis, one of the largest distribution network operators in the Netherlands, has adapted its load forecasting method for HV/MVtransformers to incorporate the influence of distributed generation. This new method involves the making of separate forecasts for demand and generation and determining the resulting transformer loading, based on the known correlation between demand and generation  

This paper presents an effective voltage control strategy for the autonomous operation of a medium voltage (MV) microgrid under nonlinear and unbalanced load conditions. The main objectives of this strategy are to effectively compensate the harmonic and negative-sequence currents of nonlinear and unbalanced loads using distributed generation (DG) units. The proposed control strategy consists of a multi-proportional resonant controller (MPRC) whose parameters are assigned with particle swarm optimization (PSO) algorithm. The optimization function is defined to minimize the tracking error at the specific harmonics considering the stability limitations. In this paper the performance of the... 

Supervisory control and data acquisition (SCADA) infrastructures have so far been brought into the huge amount of focus since the need for a more reliable power system accosting with the catastrophic events of interruptions has been raised. Hence, benefiting from an automation technology which can remotely monitor and coordinate commands to enable immediate response and switching are obviously inevitable. This paper outlines an implementable method in response to the goal of placement of remote terminal units (RTUs) which are in charge for data acquisition and control in a power distribution system. In this light, a new practical methodology based on the robust decision making (DM) method,... 

Routing methods and algorithms in "Wireless Sensor Networks" attract researchers' attention a lot recently. In order to find the optimal path in WSNs depending on their type and application, various algorithms are proposed. In this paper, an optimal path finding algorithm based on "Game Theory" is discussed and improved. This algorithm finds a path witch is optimizing network lifetime, load distribution, and path reliability simultaneously  

In this paper, a "Game Theory" approach for finding an optimal path in a "Wireless Sensor Network" is discussed. WSN is one of the most interesting research fields in the communication networks, and is the center of attention in recent years. In our model, a pricing and payment technique is presented to obtain an optimal path in a WSN by considering reliability, energy and traffic load. The proposed algorithm is able to find a path which improves network lifetime, load distribution and path reliability