Study on Protection for Islanded Micro-Grid

2012 ◽  
Vol 614-615 ◽  
pp. 916-920
Author(s):  
Xue Ling Zhu ◽  
Fei Han ◽  
Jia Liu
Keyword(s):  
Distributed Generation ◽  
Power Distribution ◽  
Distribution System ◽  
Short Circuit ◽  
Relay Protection ◽  
Short Circuit Current ◽  
Power Distribution System ◽  
Protection Strategy ◽  
Islanded Operation ◽  
Micro Grid

Technology of Micro-grid emerges, and power distribution system faults, allowing for the distributed generation keeping alive the islanded operation with the important load . But if the interior of Micro-grid happens a fault again, the short-circuit current of Micro-grid is so insufficient that traditional current protection can not play a part in the protection. In order to solve this problem, it introduced a new relay protection strategy, and provided the basis for the relay protection design of Micro-grid in the future.

scholarly journals Active Reduction of Short-Circuit Current in Power Distribution Systems

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 334
Author(s):  
Esteban Pulido ◽  
Luis Morán ◽  
Felipe Villarroel ◽  
José Silva
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Power Converter ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
In Series

In this paper, a new concept of short-circuit current (SCC) reduction for power distribution systems is presented and analyzed. Conventional fault current limiters (FCLs) are connected in series with a circuit breaker (CB) that is required to limit the short-circuit current. Instead, the proposed scheme consisted of the parallel connection of a current-controlled power converter to the same bus intended to reduce the amplitude of the short-circuit current. This power converter was controlled to absorb a percentage of the short-circuit current from the bus to reduce the amplitude of the short-circuit current. The proposed active short-circuit current reduction scheme was implemented with a cascaded H-bridge power converter and tested by simulation in a 13.2 kV industrial power distribution system for three-phase faults, showing the effectiveness of the short-circuit current attenuation in reducing the maximum current requirement in all circuit breakers connected to the same bus. The paper also presents the design characteristics of the power converter and its associated control scheme.

scholarly journals Resonance Propagation and Elimination in Integrated and Islanded Microgrids

2018 ◽  
Vol 9 (3) ◽  
pp. 1445
Author(s):  
K. V. Siva Reddy ◽  
SK. Moulali ◽  
K. Harinadha Reddy ◽  
Ch. Rami Reddy ◽  
B. V. RajannaRajanna ◽  
...  
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Control Method ◽  
Short Circuit ◽  
Open Circuit ◽  
Propagation Model ◽  
Power Distribution System ◽  
Micro Grid ◽  
Virtual Impedance ◽  
Resonance Propagation

In this paper, a micro grid resonance propagation model is investigated. To actively mitigate the resonance using DG units, an enhanced DG unit control scheme that uses the concept of virtual impedance is proposed. It can be seen that a conventional voltage-controlled DG unit with an LC filter has a short-circuit feature at the chosen harmonic frequencies, whereas a current-controlled DG unit presents an open-circuit characteristic. The application of underground cables and shunt capacitor banks may introduce power distribution system resonances. This paper additionally focuses on developing a voltage-controlled DG unit-based active harmonic damping technique for grid-connected and islanding micro grid systems. An improved virtual impedance control method with a virtual damping resistor and a nonlinear virtual capacitor is proposed. The nonlinear virtual capacitor is used to compensate the harmonic dip on the grid-side inductor of a DG unit LCL filter. The virtual resistance is principally answerable for micro grid resonance damping. The effectiveness of the proposed damping method is examined using each a single DG unit and multiple parallel DG units<strong>.</strong>

scholarly journals Design and computational modeling of fault current limiter topologies

2020 ◽  
Author(s):  
Alexandre Bitencourt ◽  
Daniel H. N. Dias ◽  
Bruno W. França ◽  
Felipe Sass ◽  
Guilherme G. Sotelo
Keyword(s):  
Electric Power ◽  
Distributed Generation ◽  
Distribution System ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Economic Feasibility ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Fault Current Limiters ◽  
Current Limiter

The increase in demand for electric power and the insertion of a distributed generation led to the rise of the short-circuit current in substations. Most of these Brazilian substations were designed decades ago, because of that their equipment may not support the new short-circuit current levels. To protect the installed equipment and avoid excessive costs replacing old devices, it is possible to install Fault Current Limiters (FCLs). This document is a report from an R&D project that evaluated FCL topologies considering real parameters in simulation from used equipment, concluding that the selected FCL topologies accomplished their technical objective. However, before implementing these topologies in the distribution system, one should consider the technical and economic feasibility of using semiconductor switching devices.

scholarly journals Flexibility Enhancement in an Islanded Distribution Power System by Online Demand-Side Management

2019 ◽  
Vol 217 ◽  
pp. 01020 ◽  
Author(s):  
Margarita Chulyukova ◽  
Nikolai Voropai
Keyword(s):  
Power System ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Load Shedding ◽  
Load Management ◽  
Daily Maximum ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
Islanded Operation

The paper considers the possibilities of increasing the flexibility of power distribution systems by real-time load management. The principles of the implementation of special automatic systems for this purpose are proposed. These systems enable some loads of specific consumers of the power distribution system switched to islanded operation to “shift” from the daily maximum to the minimum, which makes some generators available to connect certain essential consumers disconnected earlier by under-frequency load shedding system to the power system. The approach under consideration is illustrated by a power system with distributed generation.

Impact of Distributed Generation on the Fault Current in Power Distribution System

2017 ◽  
Vol 6 (2) ◽  
pp. 357
Author(s):  
Zuhaila Mat Yasin ◽  
Izni Nadhirah Sam’ón ◽  
Norziana Aminudin ◽  
Nur Ashida Salim ◽  
Hasmaini Mohamad
Keyword(s):  
Power System ◽  
Distributed Generation ◽  
Power Distribution ◽  
Distribution System ◽  
Test System ◽  
Optimal Location ◽  
Fault Current ◽  
Double Line ◽  
Power Distribution System ◽  
The Impact

<p>Monitoring fault current is very important in power system protection. Therefore, the impact of installing Distributed Generation (DG) on the fault current is investigated in this paper. Three types of fault currents which are single line-to-ground, double line-to-ground and three phase fault are analyzed at various fault locations. The optimal location of DG was identified heuristically using power system simulation program for planning, design and analysis of distribution system (PSS/Adept). The simulation was conducted by observing the power losses of the test system by installing DG at each load buses. Bus with minimum power loss was chosen as the optimal location of DG. In order to study the impact of DG to the fault current, various locations and sizes of DG were also selected. The simulations were conducted on IEEE 33-bus distribution test system and IEEE 69-bus distribution test system. The results showed that the impact of DG to the fault current is significant especially when fault occurs at busses near to DG location.</p>

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