Integrated planning of electric distribution systems

Orientadores: Ariovaldo Verandio Garcia, Marcos Julio Rider FloresTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de ComputaçãoAbstract: In this work the Distribution System Integrated Planning (DSIP) problem is modeled as a mixed integer (binary) nonlinear program problem. Two techniques were investigated to solve this problem. First, a specialized Constructive Heuristic Algorithm (CHA) was implemented. A sensitivity index is used in each step of the CHA to add a circuit, a substation, a capacitor bank or a voltage regulator to the distribution system. This sensitivity index is obtained by solving the DSIP problem considering the numbers of circuits and substations to be added as continuous variables (the DSIP relaxed problem). The objective of the DSIP is to minimize the operation costs and the construction costs of circuits, substations, capacitors and voltage regulators, which are subjected to constraints of power balance, voltage magnitude, maximum circuit and substation capacities, taps control and radiality constraint. In addition, a local improvement phase to improve the initial solution of the CHA and a branching technique to avoid the infeasibility cases in the distribution system operation were includedDoutoradoEnergia EletricaDoutor em Engenharia Elétric

Capacity Market for Distribution System Operator – with Reliability Transactions – Considering Critical Loads and Microgrids

Conventional distribution system (DS) asset planning methods consider energy only from transmission systems (TS) and not from distributed energy resources (DER), leading to expensive plans. Newer transactive energy DS (TEDS) asset planning models, built on capacity market mechanisms, consider energy from both TS and DERs, leading to lower-cost plans and maximizing social welfare. However, in both methods the cost of higher reliability requirements for some users are socialized across all users, leading to lower social welfare. In this paper, a novel transactive energy capacity market (TECM) model is proposed for DS asset planning. It builds on TEDS incremental capacity auction models by provisioning for critical loads to bid and receive superior reliability as a service. The TECM model considers these reliability transactions, in addition, to selling energy transactions from TS and DERs, buying energy transactions from loads, and asset upgrade transactions from the network operator. The TECM model allows for islanded microgrids and network reconfiguration to maximize social welfare. The TECM model is assessed on several case studies, demonstrating that it achieves higher social welfare and a lower plan cost

Mesenchymal Stem Cell Treatment Perspectives in Peripheral Nerve Regeneration: Systematic Review

Traumatic peripheral nerve lesions affect hundreds of thousands of patients every year; their consequences are life-altering and often devastating and cause alterations in movement and sensitivity. Spontaneous peripheral nerve recovery is often inadequate. In this context, nowadays, cell therapy represents one of the most innovative approaches in the field of nerve repair therapies. The purpose of this systematic review is to discuss the features of different types of mesenchymal stem cells (MSCs) relevant for peripheral nerve regeneration after nerve injury. The published literature was reviewed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A combination of the keywords “nerve regeneration”, “stem cells”, “peripheral nerve injury”, “rat”, and “human” were used. Additionally, a “MeSH” research was performed in PubMed using the terms “stem cells” and “nerve regeneration”. The characteristics of the most widely used MSCs, their paracrine potential, targeted stimulation, and differentiation potentials into Schwann-like and neuronal-like cells are described in this paper. Considering their ability to support and stimulate axonal growth, their remarkable paracrine activity, their presumed differentiation potential, their extremely low immunogenicity, and their high survival rate after transplantation, ADSCs appear to be the most suitable and promising MSCs for the recovery of peripheral nerve lesion. Clinical considerations are finally reported

Consumo de Energia Elétrica e Jitter em redes IEEE 802.11 / Power Consumption and Jitter in IEEE 802.11 Networks

O presente trabalho tem como objetivo verificar a relação entre o consumo de energia elétrica e o jitter em redes de comunicação. Foram realizados estudos sobre as redes de comunicação, QoS, potência ativa, e foi implementada uma bancada de testes para a aferição dessa relação. Todos os ensaios foram realizados nos laboratórios da PUC-Campinas. Como conclusão, foi observado que não existe relação entre o aumento do consumo de energia elétrica e o aumento de valores de jitter

Optimal allocation of energy storage devices in distribution systems considering lifetime characteristics of batteries

The introduction of energy storage devices represents an important element for supporting the operation of distribution networks. Considering the presence of renewable energy sources, the use of these devices provides ancillary services and energy balance flexibility to the network. This work presents a mixed integer second order cone programming model for solving the problem of allocating energy storage devices in radial distribution networks. The model provides the optimal allocation of the devices in the grid as well as their optimal operating cycle in order to minimize system operational costs considering also the preservation and the life of these devices. The use of existing classical optimization tools and the conic model ensures convergence to the optimum operating point. To demonstrate the accuracy of the mathematical model developed and the efficiency of the solution technique, an 11-bus test system with the presence of renewable energy sources is used in the simulationsIEEE International Conference on Power System Technology (POWERCON)sem informaçã

Grasp Algorithm For Charging Coordination Of Plug-in Electric Vehicles In Electrical Distribution Systems

A new methodology, based on the GRASP (Greedy Random Adaptative Search Procedure) metaheuristic is proposed in this paper in order to solve the plug-in electric vehicle (PEV) charging coordination problem in electrical distribution systems (EDSs). The proposed method minimizes the total operational costs of the EDS by determining an optimal schedule for the electric vehicle battery charging. Additionally, priority conditions on the PEV charging are considered. The efficiency of the proposed methodology is verified using a 449-node system. The results shown that the achieved solution provides an economic operation of the EDS, while satisfying operational constraints.IEEE PES Transmission & Distribution Conference and Exposition-Latin America (PES T&D-LA)SEP 20-24, 2016Morelia, MEXIC

An efficient implementation of tabu search in feeder reconfiguration of distribution systems

This paper presents an efficient tabu search algorithm (TSA) to solve the problem of feeder reconfiguration of distribution systems. The main characteristics that make the proposed TSA particularly efficient are a) the way in which the neighborhood of the current solution was defined; b) the way in which the objective function value was estimated; and c) the reduction of the neighborhood using heuristic criteria. Four electrical systems, described in detail in the specialized literature, were used to test the proposed TSA. The result demonstrate that it is computationally very fast and finds the best solutions known in the specialized literature. © 2012 IEEE

Optimal allocation of capacitors in radial distribution systems with distributed generation

This paper presents a mixed-integer linear programming approach to solving the optimal fixed/switched capacitors allocation (OCA) problem in radial distribution systems with distributed generation. The use of a mixed-integer linear formulation guarantees convergence to optimality using existing optimization software. The results of one test system and one real distribution system are presented in order to show the accuracy as well as the efficiency of the proposed solution technique. © 2011 IEEE

An Enhanced Genetic Algorithm to Solve the Static and Multistage Transmission Network Expansion Planning

An enhanced genetic algorithm (EGA) is applied to solve the long-term transmission expansion planning (LTTEP) problem. The following characteristics of the proposed EGA to solve the static and multistage LTTEP problem are presented, (1) generation of an initial population using fast, efficient heuristic algorithms, (2) better implementation of the local improvement phase and (3) efficient solution of linear programming problems (LPs). Critical comparative analysis is made between the proposed genetic algorithm and traditional genetic algorithms. Results using some known systems show that the proposed EGA presented higher efficiency in solving the static and multistage LTTEP problem, solving a smaller number of linear programming problems to find the optimal solutions and thus finding a better solution to the multistage LTTEP problem

A Constructive Heuristic Algorithm for Distribution System Planning

A constructive heuristic algorithm (CHA) to solve distribution system planning (DSP) problem is presented. The DSP is a very complex mixed binary nonlinear programming problem. A CHA is aimed at obtaining an excellent quality solution for the DSP problem. However, a local improvement phase and a branching technique were implemented in the CHA to improve its solution. In each step of the CHA, a sensitivity index is used to add a circuit or a substation to the distribution system. This sensitivity index is obtained by solving the DSP problem considering the numbers of circuits and substations to be added as continuous variables (relaxed problem). The relaxed problem is a large and complex nonlinear programming and was solved through an efficient nonlinear optimization solver. Results of two tests systems and one real distribution system are presented in this paper in order to show the ability of the proposed algorithm