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The main motivation of this study is to address the challenges due to high penetration of renewable distributed energy resources (DERs) and efficiently benefit from DERs in distribution system planning (DSP). This paper considers a decentralized enhanced platform for DSP which is coordinated with bulk power system planning (PSP) to keep the optimality and security of the whole power system. In the proposed coordinated approach, distribution system operators (DSOs) plan and operate DERs to upgrade their local distribution areas (LDAs), supply forecasting local load growth, and avoid or defer costly generation and transmission expansion planning at the bulk power system. The proposed DSP model... 

This paper aims at proposing a mixed-integer linear formulation to incorporate reliability-oriented costs into the expansion planning model of electricity distribution networks. In this respect, revenue lost associated with the undelivered energy caused by network interruptions as well as costs incurred by the widely used reward-penalty regulations is considered as the major reliability-related costs from distribution companies point of view. A set of mixed-integer linear equations is proposed to calculate the most common distribution system reliability indices, i.e., expected energy not served, system average interruption frequency index, and system average interruption duration index. It... 

In this paper, an energy management problem of a distribution system is studied. The energy trading among a distribution company and some aggregators controlling flexible loads and electric vehicles is modeled as a large-scale Nash bargaining problem. A distributed approach is proposed using the alternating direction method of multipliers decomposition technique, to keep privacy of traders and reduce calculation complexities. We prove that the proposed method admits a Nash bargaining solution. Since the participants' information is not available beforehand, we design an MPC-based algorithm to overcome system uncertainties. To verify the proposed approach a numerical scenario has been... 

In this paper a new framework for scheduling of available resources in the distribution networks is developed. In this respect attempts are focused on interactions between charging/discharging profiles of electric vehicles (EVs) and output power of distributed generation units. To reach this goal, the proposed framework is designed as a two-stage optimization procedure. In the first stage, the charging/discharging schedules of EVs are extracted running a linear programing optimization problem taking into account the EV users' constraints and requirements. The usage profiles of the DG units, strategy of buying electricity from the market and also the final charging/discharging patterns of the... 

Medium power distributed energy resources (DERs) are commonly connected to medium voltage distribution systems via voltage source converters (VSCs). Several guidelines and standards have been developed to establish the needed criteria and requirements for DERs interconnections. In this respect, it is preferred to reinforce the VSC fault ride through (FRT) capability, which considerably minimizes the DG outage period and reconnection time and results in a resilient system against short circuits. Considering the significant number of asymmetrical faults in distribution systems, the VSC response in such conditions must be investigated, and consequently, its FRT capability must be reinforced. In... 

Increasing rate of renewable energy sources (RESs) integration in the distribution system and development of multi-microgrids (MMG) structures have changed the operational condition of power grids. In this context, the stochastic and intermittent nature of the RESs has increased the need for ramp up power to balance the supply and demand when electricity generation of these resources drops. Moreover, bulk power generation units, which conventionally have the possibility to provide flexibility ramp, would face lack of financial justification for expansion and operation in a system with high rate penetration of RESs. Therefore, distribution system operators (DSOs) should rely on local... 

The two-dimensional thermoelastic tractive rolling contact problem for a half-plane which is coated with a functionally graded material (FGM), under the plane strain deformation, is studied in this paper. A rigid cylinder rolls over the surface of an FGM coating with constant translational velocity, generating frictional heating in the slip zones of the contact area. Thermomechanical properties of the FGM vary exponentially along the thickness direction. It is assumed that the contact area consists of a central stick zone and two slip zones of the same sign. The transfer matrix method and Fourier integral transform technique are used to achieve a system of two Cauchy singular integral... 

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... 

A gossip protocol is a procedure for spreading secrets among a group of agents, using a connection graph. The goal is for all agents to get to know all secrets, in which case we call the execution of the protocol successful. We consider distributed and dynamic gossip protocols. In distributed gossip, the agents themselves instead of a global scheduler determine whom to call. In dynamic gossip, not only secrets are exchanged but also telephone numbers (agent identities). This results in increased graph connectivity. We define six such distributed dynamic gossip protocols, and we characterize them in terms of the topology of the graphs on which they are successful, wherein we distinguish... 

Reliability cost is considered as an inevitable criterion in expansion planning studies of distribution systems. However, nonlinear expressions of reliability indices aggravate complexity of planning studies. To address this issue, this letter proposes a novel method to linearize mathematical model of the reliability-based distribution expansion planning problem. Using this variant of reliability indices, reliability costs can easily be involved in mixed-integer linear programming model of distribution expansion planning. Validity of the derived expressions is tested by simulation results. © 1969-2012 IEEE  

In this paper, a two-stage charging management framework is proposed to exploit the potential flexibility of Electric Vehicles (EVs). The aim is to reduce drastic variations in distribution system net load caused by integration of intermittent renewable distributed generation (DG) units. In the first stage, a home-based charging method is formulated in which the desired charging schedule of EVs is obtained by minimizing the cost of energy taking into account owners' preferences. The attained charging schedules are then announced to EVs Coordinator Agent (ECA) which, as the second stage, applies an LP optimization to reduce the cost of ramp provision. Moreover, an incentive scheme is... 

Numerous operational issues including voltage deviation and instability arise in distribution networks with insufficient reactive support. Static issues have been widely studied for years, and some dynamic ones are recently gaining attention due to the proliferation of distributed generation (DG). In this paper, a two-step reactive compensation planning procedure is proposed to address these challenges. In the first step, passive compensators are optimally sited and sized using a metaheuristic algorithm in order to improve steady-state indices including power efficiency, voltage profile, and static voltage stability. In the second step, a static synchronous compensator (Statcom) is located... 

Employing more flexibility in power systems is one of the main challenges brought about by integrating more renewable energy sources in power systems. A promising way to overcome this challenge is to have local sources of flexibility in distribution level. In this respect, a novel approach is introduced in this paper for multi-stage distribution system expansion planning which jointly considers expansion of the network assets as well as flexibility enhancement. To this end, construction and reinforcement of feeders and substations are considered as various alternatives for network expansion. Moreover, installation of conventional dispatchable distributed generation units is selected as the... 

Technical virtual power plant (TVPP) plays an important role in modern power systems by coordinating distributed energy resources (DERs) to participate in wholesale electricity market. This paper presents a framework for TVPP's energy management in an active distribution system with diverse uncertain DERs. The TVPP participates in wholesale day-ahead (DA) market and schedules DERs in order to maximize its profit, while considers actual locations of DERs in the network and takes network operational constraints into account. Many diverse DERs including DGs, renewable energy sources (RESs), and several load sectors comprising EVs, heating, ventilation, and air conditioning (HVAC) systems and... 

A significant share of losses in power systems occurs in distribution network due to lower voltages and longer lines. On top of that, unbalanced operation causes additional losses in these networks. In recent years with the development of distributed generation connected to the distribution grid, the concern over frequency and intensity of unbalanced operation has risen. Reconfiguration of these distribution networks plays a significant role in power loss minimization and voltage quality enhancement. The uncertainty regarding grid-connected DG resources and net loads are among the critical factors that must be taken into account. To do so, in this paper a novel Fuzzy-based reconfiguration... 

Purpose: Microgrids are inclined to use renewable energy resources within the availability limits. In conventional studies, energy interchange among microgrids was not considered because of one-directional power flows. Hence, this paper aims to study the optimal day-ahead energy scheduling of a centralized networked multi-carrier microgrid (NMCMG). The energy scheduling faces new challenges by inclusion of responsive loads, integration of renewable sources (wind and solar) and interaction of multi-carrier microgrids (MCMGs). Design/methodology/approach: The optimization model is formulated as a mixed integer nonlinear programing and is solved using GAMS software. Numerical simulations are... 

This paper focuses on expansion co-planning studies of natural gas and electricity distribution systems. The aim is to develop a mixed-integer linear programming (MILP) model for such problems to guarantee the finite convergence to optimality. To this end, at first the interconnection of electricity and natural gas networks at demand nodes is modelled by the concept of energy hub (EH). Then, mathematical model of expansion studies associated with the natural gas, electricity and EHs are extracted. The optimization models of these three expansion studies incorporate investment and operation costs. Based on these separate planning problems, which are all in the form of mixed-integer nonlinear... 

Growing widespread outages in power systems caused by natural disasters have highlighted the necessity of applying defensive approaches with the goal of prompt service restoration. In this context, this paper proposes a stochastic model with the goal of optimally using proactive operational actions before the upcoming disturbance hits. The actions considered in this study include network reconfiguration and crew prepositioning. To take the effective actions, the model simulates probable damages caused by the events via a set of scenarios generated by Monte Carlo simulation method. The proposed model aims at minimizing the expected load curtailment caused by the event over the scenarios. To... 

This paper presents a mathematical model for simultaneous deployment of protective devices (PDs) and controlling devices (CDs) in distribution networks. The PDs include fuses and reclosers and the CDs are remote controlled switches (RCSs) and manual switches (MSs). The model is to minimize equipment costs as well as sustained and momentary interruption costs. It considers the coordination of fuses and reclosers during temporary faults involving fuse saving and fuse blowing schemes. The model is in mixed integer programming (MIP) fashion which can be effectively solved with available solvers. The performance of the proposed model is verified through applying it to Bus 4 of Roy Billinton test... 

Cloud computing technology, which is a new model of service provisioning in distributed systems, has been raised as a way to execute workflow applications. To profit from this technology for executing workflow applications, it is necessary to develop workflow scheduling algorithms that consider different QoS parameters such as execution time and cost. Therefore, in this paper, we focus on two criteria: makespan (completion time) and execution cost of workflow application and propose a scheduling algorithm named CB-DT (Constrained Budget-Decreased Time) which aims to create a schedule that decreases the makespan while satisfying the budget constraint of the workflow application. In the...