The Study on Configuration and Setting of Relay Protection when Distributed Generation Accesses to Distribution Network

2012 ◽  
Vol 433-440 ◽  
pp. 1950-1956
Author(s):  
Xiao Ming Li ◽  
Sha Li ◽  
Peng Lu ◽  
Shu Qiong Liu

When distributed generation (DG) accesses to non-system bus , and the power capacity increases to a certain extent, it will cause malfunction of protective devices, as a result of which ,protective devices lose selectivity. This paper analyzes influence to relay protection of power system as a result of the access of DG, establishes a model of the access of DG, and proposes principles of reconfiguration of protection devices, and re-setting of relay protection when DG accesses to power system. This method provides a theoretical basis for designing of DG accessing to power system, reconfiguration of protection devices and re-setting of relay protection.

2012 ◽  
Vol 433-440 ◽  
pp. 5924-5929 ◽  
Author(s):  
Jie Dong ◽  
Ya Jun Rong ◽  
Chun Jiang Zhang

With the connection of distributed generation (DG), structure of traditional distribution network changes and original relay protection scheme should be adjusted. On the basis of introducing the concept and advantages of distributed generation, this paper discusses the influence of distributed generation with different position or different capacity on current protection. The paper analyzes magnitude and distribution of fault current under short-circuit condition and change curves of fault current are given, which provides some theoretical basis for new relay protection scheme.


Author(s):  
Arvind Raj ◽  
Nur Fadilah Ab Aziz ◽  
Zuhaila Mat Yasin ◽  
Nur Ashida Salim

Voltage instability in power distribution systems can result in voltage collapse throughout the grid. Today, with the advanced of power generation technology from renewable sources, concerns of utility companies are much being focused on the stability of the grid when there is an integration of distributed generation (DG) in the system.  This paper presents a study on DG units placement and sizing in a radial distribution network by using a pre-developed index called Voltage Stability Condition Index (VSCI). In this paper, VSCI is used to determine DG placement candidates, while the value of power losses is used to identify the best DG placement. The proposed method is tested on a standard 33-bus radial distribution network and compared with existing Ettehadi and Aman methods. The effectiveness of the method is presented in terms of reduction in power system losses, maximization of system loadability and voltage quality improvement. Results show that VSCI can be utilized as the voltage stability indicator for DG placement in radial distribution power system. The integration of DG is found to improve voltage stability by increasing the system loadability and reducing the power losses of the network.


2021 ◽  
Vol 71 (1&2) ◽  
pp. 5
Author(s):  
Genghuang Yang ◽  
Wenbin Sun ◽  
Xiayi Hao ◽  
Yingmei Zhang ◽  
Li Yang ◽  
...  

Small hydropower station, when producing power energy to power system through the distribution network, may lead to the change of the detected current in relay protection and the protection coverage. In this paper, IEEE7 based network is formed in the platform of PSCAD/EMTDC to analyze the effects of distribution network in current protection when a small hydropower station is linked in. The running of relay protection in Section I and II is simulated to obtain the difference of current variation of network with or without small hydropower station. Also the key parameters are calculated to point out the maximum generation capacity of the small hydropower station in case of reliable and sensitive current protection.


Author(s):  
Su Hlaing Win ◽  
Pyone Lai Swe

A Radial Distribution network is important in power system area because of its simple design and reduced cost. Reduction of system losses and improvement of voltage profile is one of the key aspects in power system operation. Distributed generators are beneficial in reducing losses effectively in distribution systems as compared to other methods of loss reduction. Sizing and location of DG sources places an important role in reducing losses in distribution network. Four types of DG are considered in this paper with one DG installed for minimize the total real and reactive power losses. The objective of this methodology is to calculate size and to identify the corresponding optimum location for DG placement for minimizing the total real and reactive power losses and to improve voltage profile   in primary distribution system. It can obtain maximum loss reduction for each of four types of optimally placed DGs. Optimal sizing of Distributed Generation can be calculated using exact loss formula and an efficient approach is used to determine the optimum location for Distributed Generation Placement.  To demonstrate the performance of the proposed approach 36-bus radial distribution system in Belin Substation in Myanmar was tested and validated with different sizes and the result was discussed.


2021 ◽  
Author(s):  
Haymanot Takele Mekonnen

Abstract BackgroundOne of the new technologies in generating power near the distribution system is called distributed generation which has supportive and destructive characteristics to the power system protection. One of the destructive characteristics of distributed generation is increasing the level of fault current to the protective equipment of the power system. In addition to increment of fault, it also alters the radial nature of the power distribution system and cause the power bidirectional rather than unidirectional. Integration of distributed generation to the distribution network causes increment of fault current effect, reliability drop, and affects security of protection system. The level of failure of protection be contingent on type, size, location and number of distributed generation. This fault current can cause a great damage to the electrical equipment with the miss operations of protective devices. The main aim of this paper is analysis of the fault current level to the protection of distribution network due to the integration of distributed generation which concerns on solar distributed generation, wind distributed generation and combination of solar and wind distributed generations at a time. This paper conducts the analysis for the increment of fault current by the integration of distributed generation and its impact on distribution network protection. ResultsThe analysis and the modeling are conducted on the 15KV distribution network of the radial feeder in Debre Markos town. This paper has covered the ling to ground, line to line and three phase fault analysis and their impact on the protection of distribution system for the wind and solar distributed generation types. After the integration of the distributed generation the fault current is increased by 0.529KA for three phase, 0.74KA for line to ground, 0.467KA for line to line and 0.523KA for line to line to ground. ConclusionsThis paper confirms designing distribution network without forecasting the future demand of electric power users give the protection equipment additional requirement. As the result, the fault current after the integration of distributed generation to the distribution network have great value in terms of power system protection.


2014 ◽  
Vol 1070-1072 ◽  
pp. 923-928
Author(s):  
Peng Sun ◽  
Ming Wu Luo ◽  
Zhao Xia Sun ◽  
Tian Ci Liu ◽  
Chang Hong Deng ◽  
...  

In light of the rapid development of the electric power grid, the integrated application of distributed generation (DG) units can be considered as a key driver. Nevertheless, along with large number of DG units are connected into a distribution network, maybe different kinds of effects are accordingly induced. In particular, regarding the configured relay protection, its selectivity and sensitivity may be affected. In this paper, the penetration capacity analysis of DG considering overcurrent relay protection and flux-coupling type FCL is conducted. Under different fault conditions, the theoretical impacts of introducing DG on the fault current are investigated, and a flux-coupling type FCL is suggested to limit the fault current and potentially enhance the DG’s access capacity. Furthermore, the detailed simulation model of a typical distribution network integrated with the DG and FCL is created. From the simulation results, the employment of the FCL can effectively reduce the fault current’s negative influence on the DG, and improve the DG’s access capacity to a certain extent.


2021 ◽  
pp. 12-15
Author(s):  
Elena Zenina ◽  

In the modern conditions of the development of the electric power complex, relay protection and automation devices play a special role related to protection against possible damage resulting from violations of normal operating modes, both of individual elements and the entire power system as a whole. This, in turn, directly affects the reliable and stable functioning of the main power elements and electrical equipment. Damage to the power part of the equipment of an electric grid complex can be caused by changes in the main parameters of the normal mode: a change (increase) in currents leads to overloads and, in the limit, to short circuits, a decrease in voltage leads to an avalanche of voltage and disruption of the operation of electric motors connected to the damaged section, and an increase in voltage leads to overvoltages in certain sections. In addition, violations associated with a decrease in the transmitted active power lead to a change in frequency, and a violation of the reactive power balance leads to a change in voltage in certain sections, which generally leads to noncompliance with the power balance and loss of stable operation of the power system. The main reasons for failures in operation, false and excessive triggering of microprocessor relay protection devices are considered. The main ways of solving the problem of electromagnetic compatibility in the electric power industry are identified. A solution is proposed to improve the reliability of the operation of microprocessor relay protection devices and the way of development of the problem of electromagnetic compatibility in the electric power industry is shown.


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