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Finding minimum number of connecting lines is as important as locating phasor measurement units (PMUs) for full observability of power system. Therefore, a PMU placement method should determine both optimum buses and lines, since utilities can make better decisions for monitoring of power system with this information. Moreover, it is necessary to provide direct observation of critical buses and transmission...
Energy consumption in battery-based nodes and network traffic optimization are two main challenges associated with wireless sensor networks and the traditional digital control architecture is not optimized from these perspectives. Thus, using optimal control theory and event-based control concept, we propose a novel architecture to tackle the regulation and tracking problems in wireless sensor networks...
This study proposes an effective analyticalheuristic approach for solving optimal placement and sizing of multiple distributed generator problem to achieve a high loss reduction in large-scale distribution network. Proposed analytical- heuristic method (AHM) is based on improvement of LSF (loss sensitivity factor) method. AHM utilizes PSO (particle swarm optimization) algorithm to find the optimal...
This paper presents a mathematical formulation for centralized energy management strategy (EMS) of microgrids in both grid connected and isolated modes. The microgrid energy management is formulated as an unit commitment problem with regard to the distribution network and the corresponding constraints leading to a mixed-integer non-linear programming (MINLP) formulation. In order to reduce the computational...
This paper proposes a practical time-phased model to analyze the vulnerability of power systems over a time horizon, in which the scheduled maintenance of network facilities is considered. This model is deemed as an efficient tool that could be used by system operators to assess whether how their systems become vulnerable giving a set of scheduled facility outages. The final model is presented as...
Hierarchical learning as another way to scale up reinforcement learning and enable its applications to very hard learning problems. Hierarchical learning is a divide-and-conquer technique a complex learning problem is decomposed into small pieces so that they can be easily solved. The option framework is one way to using hierarchical learning in reinforcement learning. In this paper we have used the...
In this paper, a new dynamic model for the investment process in the power system, including renewable energy sources is proposed. In this regard, three thermal units including base, intermediate and peak load technologies with wind turbine generators have been considered. In the proposed framework, the uncertainty of the thermal units due to their outages as well as the uncertainty of wind power...
One of the major issues in smart grid monitoring, protection and power quality event identification is accurate phasor estimation. Proper phasor estimation is more important especially during fault, because the signals doesn’t have pure sine wave anymore and include different harmonic components and Decaying DC offset, so Proper phasor estimation in smart grids are very important issue. This paper...
Increasing redundant paths in transmission grids has always been thought to be a tool to enhance service reliability. However, network equations by intertwining power flows through redundant paths impose more limits on systems with more redundancy. Accordingly, autonomous removing of a few lines may relief capacity limit violations in some contingency events thereby enhancing service reliability....
Broadband signal transmission through communication channels in home environments is one of the interesting topics in the field of intelligent buildings. Building designers are interested in transferring multimedia content with minimum cost, energy consumption, and acceptable quality. Limitations and drawbacks of existing transmission systems such as coaxial cable, wireless transmission, etc., have...
This paper presents a control scheme based on fractional proportional-integral controller for improving the load sharing among parallel-connected inverter based distributed generation in microgrid. The control context is based on the current control in which through the use of the proposed strategy dynamically preserves the proportional power sharing properties of the DG units. The results show that...
Recently, the development of Microgrids (MGs) causes challenges that need considerable attention. One of the most challenging problems which occurs when a MG is islanding or disconnecting from the main grid, since during this event frequency and voltage of MG deviate from their nominal values. Energy Storage Systems (ESSs) are used to solve this problem. In this paper, Flywheel Energy Storage System...
Microgrids are defined as power systems, which have small scale and low voltage level. Isolated and remote areas, small loads and places are usually faced with problem of lack of accessibility to main power grid. Microgrids can be an appropriate choice for these areas regarding to environmental and economic aspects. These grids are appropriate to meet various kinds of loads such as domestic, industrial...
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...
In this paper, we investigate the performance of cooperative amplify-and-forward (AF) multi-relay networks with relay selection strategy over independent and identically distributed (i.i.d.) Nakagami-m fading channels. In this system we study multiuser cooperative relaying to have a secure transmission from source to destination, since transmitted information may be wiretapped by multiple eavesdroppers...
Environmental crises and global warming, arising from fossil fuels, and the urgent need for electrical energy generation, have led the international community to make a greater use of renewable energy resources. Among renewable energy resources, wind units, due to their high efficiency, has attracted more attention. However, variable and unpredictable nature of wind speed, causes wind units to be...
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