Microgrid Fault Analysis Based on Multiple Distributed Generations

2012 ◽  
Vol 614-615 ◽  
pp. 1820-1826
Author(s):  
Xue Shun Ye ◽  
Long Zhou ◽  
Xi Sheng Tang

A microgrid is composed of multiple distributed generations (DGs).The amplifier and directions of micro-grid power are quite stochastic with the existence of the DGs. It results in great challenges on the adaptability and coordinate issue of protection. The mathematical and simulation models of photovoltaic, AWTG (asynchronous wind turbine generations), DEG (diesel engine generation) and energy storage are established and a typical microgrid containing multiple DGs is also introduced in this paper. It is demonstrated that the transient behavior of microgrid during fault depends mainly on the penetration level of different type of DGs. The simulation results verified that the transient characteristics of fault can provide theoretical basis for the protection of microgrid.

2013 ◽  
Vol 644 ◽  
pp. 317-320
Author(s):  
Chang Xi Ji ◽  
Yu Rong Jiang ◽  
En Zhe Song ◽  
Mei Liang Yin ◽  
Jun Sun

This paper establishes the simulation model of the electronic unit pump diesel engine with Matlab/Simulink and AMESim. Provide a theoretical basis for the study of electronic unit pump diesel. The diesel model is built with Matlab/Simulink simulation software and the electronic unit pump is constructed in AMESim environment. To evaluate the model, a co-simulation method with AMESim/Simulink is used. The simulation results show the model is available. And it is significant in theoretical study of electronic unit pump diesel.


Author(s):  
Saili Li ◽  
Yiping Dai ◽  
Maoqing Li ◽  
Lin Gao

Wind energy has been examined as a clean and economic resource, however, the intermittent and fluctuate feature of which makes it necessary to couple with an energy storage system for compensating the wind energy curtailments. A micro-grid with a compressed air energy storage (CAES) system may help to eliminate the problem resulted from high wind power penetration in the power grid. What is more, it can reduce the network losses. A micro-grid system coupled with small wind turbine presented in this paper. Off-peak power from the wind turbine is used to drive the compressor which serves for the storage vessel. The compressed air supercharges the gas turbine directly when wind energy is not sufficient to guarantee the required load. A dynamic model is built to test the behavior of the system. A statistical model based on stochastic weather data is used to simulate the output of the wind turbine for one day at quarter-hour intervals. An accurate model of CAES includes a compressor, a high pressure vessel and a gas turbine is built in details. A control system is developed to achieve outstanding system’s characteristics like great control performance, stable operation and fast starting. The simulation results show that the CAES can compensate the wind turbine and make the most of wind energy.


2019 ◽  
Vol 8 (2) ◽  
pp. 3972-3978

This article researched controlling and operating a dc micro grid that can be operated in connected grid and island modes. Dc micro grid comprises of a wind turbine, dc loads, grid-connected converter arrangement and a battery energy storage scheme. When the scheme is linked to the grid, the active energy is balanced during standard operation to guarantee a continuous dc voltage. In grid ac failure, automatic power balancing is attained by combining the battery energy storage scheme as well as the grid converter. To demonstrate that the system can function under island circumstances, a synchronized battery scheme approach, wind turbine and load managing, including load shedding, is suggested. MATLAB simulations are provided to demonstrate the powerful operational presentation and confirm the predicted control system under different working situations, such as varying in load, grid ac fault, variable generation and islanding


Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.


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