Structural Evaluation for Distribution Networks with Distributed Generation Based on Complex Network

Structural analysis based on complex network theory has been considered promising for security issues of power grids. At the same time, modern power distribution networks with more Distributed Generations (DGs) and Energy Storage Systems (ESS) have taken on more challenges in operation and security issues. This paper proposed a dedicated metric named as Power-Supply-Ability for power distribution networks based on net-ability. Special features of DGs, such as relations of capacities, identification of effective supply area, and limitation in continuous power supply, have been considered in definition. Furthermore, a novel opinion is proposed that the extent of improvement for operation and security by adding DGs also depends on the original structure of the distribution networks. This is an inherent ability of the original networks and could be quantitatively analyzed. Through case studies, this method has been proved to be effective in identifying potential structural vulnerabilities of distribution networks; particularly the impact of DGs on security has been studied. Furthermore, it can help in site selection for DGs by providing different priorities of locations compared with results of other works. This can help to complement other methods to construct a more comprehensive methodology by considering aspects of security, economy, and quality

Integración óptima de sistemas de generación solar fotovoltaica para la minimización de costos totales de operación anual aplicando el algoritmo de la Viuda Negra

Este artículo presenta un análisis de la caracterización físico-mecánica de un concreto geopolimérico fibrorreforzado, cuya matriz HCV está conformada por 90 % ceniza volante (CV) y 10 % cemento portland ordinario (OPC); se utiliza como activador alcalino una solución compuesta por silicato e hidróxido de sodio (NaOH, Na2SiO3) y agua. El refuerzo utilizado fueron fibras de acero SikaFiber Xorex incorporadas a la matriz en proporciones de 50 y 75 kg/m3. La mezcla HCV-50 reportó una resistencia a la compresión de 26,77 MPa a los 28 días de curado, por lo que se clasifica como concreto estructural según la NSR-10; a la misma edad de curado se obtuvo resistencia a la tracción indirecta de 3,49 MPa, módulo de elasticidad de 29,32 GPa, resistencia a la flexión de 5,15 MPa y tenacidad hasta la deflexión de agrietamiento (δf) de 1.971,9 N.mm. Esta mezcla, considerada la óptima, fue empleada en la fabricación de losas de concreto, las cuales presentaron una deflexión de ruptura δf de 4,45 mm, deflexión última de 16,15 mm, carga máxima soportada 15,6 kN, tenacidad de 49.464,8 N.mm hasta δf y 14.5847,3 N.mm hasta 3 veces δf. El material geopolimérico fibrorreforzado se propone además para ser utilizado en la producción de concreto proyectado (shotcrete) y en la construcción de losetas aligeradas.  The problem of the optimal location and sizing of photovoltaic (PV) sources in electrical distribution systems is addressed in this article through the application of the black widow optimization algorithm (BWOA). This problem is of mixed-integer nonlinear nature and is addressed by a master-slave type optimization strategy. In the master stage, the BWOA defines the location and size of the PV generators through discrete-continuous coding, and with this information, the slave stage (power flow for distribution) determines the electrical variables of the system, with which is evaluated the objective function and the constraints of the problem. As an objective function, the minimization of the annual costs of operation and maintenance of the system is considered, added to the total costs of purchasing energy in the electrical network for a planning period of 20 years. The numerical results in the IEEE 34- and IEEE 85-node systems show that with the proposed optimization methodology it is possible to reduce around 27% of the annual operating costs in both systems with the optimal location of three photovoltaic sources. Comparisons with metaheuristics and exact methodologies reported in the specialized literature confirm the efficiency and robustness of the proposed methodology

Structural Evaluation for Distribution Networks with Distributed Generation Based on Complex Network

Structural analysis based on complex network theory has been considered promising for security issues of power grids. At the same time, modern power distribution networks with more Distributed Generations (DGs) and Energy Storage Systems (ESS) have taken on more challenges in operation and security issues. This paper proposed a dedicated metric named as Power-Supply-Ability for power distribution networks based on net-ability. Special features of DGs, such as relations of capacities, identification of effective supply area, and limitation in continuous power supply, have been considered in definition. Furthermore, a novel opinion is proposed that the extent of improvement for operation and security by adding DGs also depends on the original structure of the distribution networks. This is an inherent ability of the original networks and could be quantitatively analyzed. Through case studies, this method has been proved to be effective in identifying potential structural vulnerabilities of distribution networks; particularly the impact of DGs on security has been studied. Furthermore, it can help in site selection for DGs by providing different priorities of locations compared with results of other works. This can help to complement other methods to construct a more comprehensive methodology by considering aspects of security, economy, and quality