Evaluation Of Microgrid Research Articles

Reliability modeling and assessment of a community microgrid with electric vehicle charging station as a critical load

Microgrids are constituted of interconnected loads and dispersed energy resources. They increase the reliability of the power supply, decrease the cost of the per unit energy and support the green environment concept. Microgrids have gained importance due to their ability to deliver reliable energy and operate in both grid-connected and off-grid/island modes. Renewable energy sources such as photovoltaic (PV) and wind can be connected to the microgrid system to generate green energy. An electric vehicle charging station (EVCS) can be deployed in microgrids powered by renewable energy sources. An effective way to handle the rapidly rising load demand of electric vehicles (EVs) is to integrate EV recharge stations into microgrids. Due to the intermittent nature of solar PV and EV load's reliability, an evaluation of microgrids becomes challenging. Assessment of the components’ failure and their impact on the system reliability is proposed using different methods. Reliability Block Diagram (RBD), Markov Reliability Modeling (MRM) and Fault Tree Analysis (FTA) - Monte Carlo simulation are used for the Reliability Modeling of a community microgrid considering EVCS as a critical load. The mean time to failure (MTTF) is computed for the entire microgrid which includes PV, wind and fuel cell systems integrated into the grid with associated power electronic devices, transmission lines, transformers and point of common coupling (PCC). MATLAB software was used to program and study the reliability aspects of the microgrid. Using the FTA MCS technique and grid functions for 45 years with 20 % reliability, significant results were obtained in terms of a MTTF rate of 26.16 years.

Una propuesta metodológica para la concepción técnica de micro-redes

En este trabajo se presenta una metodología para la concepción técnica de micro-redes. Se consideran aspectos como el levantamiento de la topología del sistema eléctrico de media tensión, la preselección de tecnologías de fuentes renovables, la priorización de la demanda eléctrica, la localización, el dimensionamiento y las estrategias de operación de los generadores distribuidos, el modelo de componentes y la evaluación de la micro-red. La metodología propone el uso de una técnica de análisis multicriterio para la priorización de la demanda y el índice de estabilidad de voltaje (SI) para la ubicación de generadores distribuidos en la micro-red. En este trabajo se utilizó la herramienta computacional de análisis de sistemas de potencia Neplan® para el modelado de componentes y evaluación del desempeño de la micro-red por medio del índice de regulación de voltaje IREG y la gestión óptima de potencia de las unidades de generación de la micro-red.

Review on Business Operation Mode and Technical Economy Evaluation of Micro-Grid

To make the advantages of smart micro-grid in economy and environment to the greatest extent, many countries choose to make detailed research on the business operation mode and technical economy of micro-grid. Based on the related research, this paper generalizes several typical user modes, and then provides a reasonable technical route to study the operation mode and technical economy of micro-grid. For its business operation mode, not only the existing proposals are analyzed, but also are its method of calculating the cost and benefits of this program. Finally, specific plans about how to assess the technical economy are also analyzed.

Study of Anti-Nonextension-Entropy Weight Application in Microgrid Evaluation

As a method in the evaluation of smart grid, anti-Shannon-entropy weight can compute index weight which is in even distribution or normal distribution, and a reasonable evaluation result can be obtained, but it is not fit for the weight computation when the index includes a distinctive event in non-unique small probability through the research. For the above problem, a novel index weight algorithmanti-nonextension-entropy weight algorithm is proposed and applied to evaluating microgrid. After constructing the typical microgrid evaluation indexes, some microgrids whose indexes include a distinctive event in non-unique small probability is taken as the research objects to find the difference of two evaluation methods based on the different anti-entropy weight algorithm, and the evaluation testing of microgrid is also performed using two methods. Theoretical analysis and simulation results show that in comparison with the traditional evaluation method the novel evaluation method can not only inherit the merits of the traditional evaluation method but also obtain the reasonable weight of index including a distinctive event in non-unique small probability, which improves the precision of microgrid evaluation.

Survey on Micro-Grid Technology

The micro-grid technologies become one of key spots in the research on distributed energy systems. In this paper, the components, systemic structure and operation modes of micro-grid are presented. From the viewpoint of technical connotation, the present research situation of key technologies for the micro-grid is reviewed. These technologies include new power electronic converter technologies, fault detection and protection, communication technologies, planning and design of micro-grid, as well as issues related to operation control and energy management such as supervisory and control architecture, control strategies and approaches, ancillary services, operation specification, modeling and simulation research in system level and unit level and micro-grid economic evaluation. The authors also point out that the optimal design of micro-grid topology and optimal configuration of distributed energy units are of significance for the implementation of maximum benefit of the whole micro-grid. Besides, the effective economic evaluation of micro-grid is a topic to be researched in detail.

Evaluation of Micro Grid including Power Storage Device

Renewable energies such as wind power or photovoltaic energy are getting attentions for view points of energy conservation and environmental issue. However, fluctuation of output power of renewable energies may cause excess variation of voltage or frequency of the grid. Increase of the amount of renewable energies would violate the quality of the grid. The micro grid in which dispersed energies compensate the variation from the renewable energies can expand the installation limit of the renewable energies by maintaining the quality of the interconnected grid. In this paper, evaluation of ratio of gas turbines, gas turbines and batteries is discussed from the point of power flow stability of the grid, efficiency and economy. Gas turbines have quicker response and lower efficiency, whereas gas engines have slower response and higher efficiency. Best ratio is discussed for higher efficiency while fluctuation of output power of the micro grid is kept in a small amount. Additionally, introducing batteries is discussed to introduce more gas engines he point of power flow stability of the grid, efficiency and economy.