scholarly journals Fault Location Scheme for Abnormal Grounding Point in Isolated Ground Wire of Large-Scale Clean Energy Transmission

2021 ◽  
Vol 9 ◽  
Author(s):  
Yunlong Wang ◽  
Nuo Chen ◽  
Xiangnan Ma ◽  
Zongzhang Yang
Keyword(s):  
Output Power ◽  
Large Scale ◽  
Wind Farm ◽  
Fault Location ◽  
Clean Energy ◽  
Output Current ◽  
Location Method ◽  
Protective Relay ◽  
Time To Build ◽  
Long Time

There is a large number of grounding switches along the isolated ground wire for the de-icing in the large-scale wind farm. If any of these grounding switches are left open by accident, this can create an unexpected abnormal grounding point in the isolated ground wire. Based on the analysis of the output power of de-icing devices, the output power of different poles can be applied for the abnormal grounding point fault location. Since the rise of output current to the rated current of de-icing devices requires a long time to build up, the protective relay may lock the de-icing device before the output current reaches the rated current. Thus, the ratio of output energy of two poles can be selected to locate the abnormal grounding point. This study verified this location method by conducting a large number of simulations.

Numerical Analysis of a Large-Scale Hydraulic Wind Farm With Integrated Hydraulic Energy Storage

2016 ◽  
Author(s):  
Daniel Buhagiar ◽  
Tonio Sant
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Large Scale ◽  
Wind Farm ◽  
Wind Farms ◽  
Strong Relationship ◽  
Pressure Control ◽  
Open Loop ◽  
Offshore Wind ◽  
Pipeline Network

Offshore wind farms are presently facing numerous technical challenges that are affecting their viability. High failure rates of expensive nacelle-based electronics and gearboxes are particularly problematic. On-going research is investigating the possibility of shifting to a seawater-based hydraulic power transmission, whereby wind turbines pressurise seawater that is transmitted across a high-pressure pipeline network. A 9-turbine hydraulic wind farm with three different configurations is simulated in the present work and a previously developed method for open-loop pressure control of a single turbine has been adapted for this multiple-turbine scenario. A conceptual quasi-constant-pressure accumulator is also included in the model. This system is directly integrated within each hydraulic wind turbine and it allows the output power from the wind farm to be scheduled on an hourly basis. The shift in control methodology when integrating storage is illustrated in the present work. Simulation results indicate a strong relationship between hydraulic performance attributes and the specific wind turbine array layout. The beneficial effects of storage can also be observed, particularly in smoothing the output power and rendering it more useable. Finally, the energy yields from 24-hour simulations of the 9-turbine wind farms are calculated. Integrated storage leads to a slight increase in yield since it eliminates bursts of high flow, which induce higher frictional losses in the pipeline network.

A Fault Detection Model for Large-Scale Circuit Communication Systems

2014 ◽  
Vol 651-653 ◽  
pp. 383-386
Author(s):  
Wen Qun Duan ◽  
Yang Yun
Keyword(s):  
Fault Detection ◽  
Traditional Method ◽  
Communication Systems ◽  
Wavelet Transformation ◽  
Large Scale ◽  
Fault Location ◽  
Detection Method ◽  
Wavelet Function ◽  
Detection Model ◽  
Long Time

In the fault detection process for large-scale circuit communication systems, the traditional method needs to exam each node to determine whether a failure exists. It is complex and needs long time which causes a certain lagging. To avoid the defects mentioned above, this paper proposes a fault detection method based on wavelet transformation that calculates the changes of coefficients of the wavelet transform and the similarity between wavelet function and the signal. This kind of fault detection can pre-process the failure might occur and effectively improve the efficiency. The experimental results approve that the proposed method can predicate the fault location and reach satisfied effects.

scholarly journals Fault location method of active distribution network based on graph theory and matrix algorithm

2021 ◽  
Vol 2121 (1) ◽  
pp. 012035
Author(s):  
Yalei Li ◽  
Xiaohong Zhang
Keyword(s):  
Graph Theory ◽  
Power Supply ◽  
Power Distribution ◽  
Network Flow ◽  
Large Scale ◽  
Fault Location ◽  
Distribution Network ◽  
Location Method ◽  
Active Distribution Network ◽  
Network Fault

Abstract In view of the large scale distributed power distribution network, distribution network from the traditional single main transformer power supply system becomes more complex broken power supply network, the trend of the distribution network flow and network frame produced change, failure fault feature information of great change, the traditional distribution network fault location method can not accurately obtain the location of the fault zone, the low accuracy of fault location, the error bigger problem a new fault location method of active distribution network combining graph theory and matrix was proposed. According to the knowledge of graph theory, the distribution network is simplified to topology diagram and described in the form of matrix, and then the fault judgment matrix is obtained through a series of matrix addition operation, and the type of fault interval can be identified accurately and quickly by combining the fault criterion table. The simulation results show that this method is simple in principle, fast and effective in criterion, suitable for the flexible operation mode of active distribution network structure, can accurately and quickly determine the fault segment, and can meet the requirements of complex distribution network fault location.

Simulation Research on Improving Low Voltage Ride through of a Wind Farm by SVC

2013 ◽  
Vol 339 ◽  
pp. 608-613 ◽  
Author(s):  
Yan Shi ◽  
Chun Xu Zhang ◽  
Guang Lei Li ◽  
Yan Cheng ◽  
Shu Min Sun
Keyword(s):  
Large Scale ◽  
Wind Farm ◽  
Fault Location ◽  
Reactive Power ◽  
Low Voltage ◽  
Negative Impact ◽  
Simulation Models ◽  
Simulation Research ◽  
Low Voltage Ride Through ◽  
The Stability

Large-scale wind farm connecting to the grid will affect the stability of the grid, therefore dynamic reactive power compensation devices need to be installed at the wind farm in order to reduce the negative impact after connecting to the grid, andimprove the low voltageridethrough capability of the grid system wind turbine. Simulation models of a wind farm and SVCare built in PSCAD. In different fault location, simulations are carried out respectively to analyze the effect of SVC on LVRT. The results show that SVC can effectively improve the LVRT capability.

scholarly journals Fault Location Method for Two-Terminal Untransposed Overhead Lines in Distribution Networks Measured by μMPMU

2021 ◽  
Vol 256 ◽  
pp. 01023
Author(s):  
Tao Wen ◽  
Fangxu Zhang ◽  
Chengbin Wang
Keyword(s):  
Large Scale ◽  
Fault Location ◽  
Rapid Development ◽  
Distribution Networks ◽  
Location Method ◽  
Overhead Lines ◽  
Average Value ◽  
Frequency Components ◽  
Location Methods ◽  
Data Windows

With the rapid development of distribution networks, two-terminal overhead lines have been used on a large scale for higher power supply reliability, thus the fault location has attracted much attention. Accurate fault location is helpful to shorten the outage time and improve the economy of operation greatly. However, since insufficient standardization of equipment selection and poor management, line parameters are usually inaccurate or even unknown, mature fault location methods based on impedance can’t be applied anymore. Also, the asymmetry caused by non-transposition in distribution networks affects the accuracy of fault location. This paper proposes a fault location method for two-terminal untransposed overhead lines without requiring line parameters. Firstly, this paper considers parameter asymmetry, and the mutual impedances between the three phases are set as different values. Secondly, the location equations rely on three-phase networks, then the self-impedance and mutual impedances are regarded as unknowns and solved directly. Finally, this method takes the average value of fundamental frequency components from different data windows, which reduces error and improves accuracy. The simulation results show that the fault location method has high accuracy, and can effectively overcome the influence of unknown line parameters and non-transposition.

scholarly journals Identification of Permanent Faults and Disturbance Induced by Deicing Based on Permutation Entropy for the Large-Scale Clean Energy Transmission in Winter

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Yunlong Wang ◽  
Tiejun Tang ◽  
Xiang Ju ◽  
Dingding Hong
Keyword(s):  
Large Scale ◽  
Clean Energy ◽  
Permutation Entropy ◽  
Multiple Time ◽  
Arc Plasma ◽  
Grounding Resistance ◽  
Protective Relay ◽  
Permanent Faults ◽  
Ice Shedding ◽  
Short Time

Ice shedding may induce isolated ground wires’ temporary grounding, which can cause electric quantities of direct current (DC) deicing devices to fluctuate. Hence, the disturbance of ice shedding is able to trigger the protective relay frequently and unnecessarily, which adversely affects the deicing process. Due to the randomness of ice shedding, the grounding resistance varies quickly; thus, the disturbance in poles of deicing devices can be detected multiple times in a short time. Moreover, the permanent fault requires steady arc plasma because of the low output voltage and current of deicing devices, which cannot bring out multiple-time disturbances in the poles. This paper proposes the identification of permanent faults and disturbance induced by deicing based on the permutation entropy, which is verified by a large number of simulations.

Study on Transient Stability Simulation of District Grid Containing High Proportion of Wind Power

2014 ◽  
Vol 1070-1072 ◽  
pp. 275-278
Author(s):  
Li Lin ◽  
Shuang Zhao ◽  
Meng Ze Yu ◽  
Bo Jian Ding
Keyword(s):  
Wind Power ◽  
Power Plants ◽  
Large Scale ◽  
Wind Farm ◽  
Fault Location ◽  
Transient Stability ◽  
Thermal Power ◽  
Wind Farms ◽  
Operating Modes ◽  
The Impact

As wind is random, intermittent and instability, with continual installation of wind farms, the impact of large scale wind farm on power system has become an important issue for integration and operation of wind farm. Aiming at studying the transient stability of district grid containing high proportion of wind power, numerical simulations with BPA for an actual district grid of China Southern Power Grid are presented. In these simulations, the interaction between the large-scale wind farm and traditional thermal power plants (TPPs) is investigated taking the different operating modes and fault location into account. The critical clearing time (CCT) is adopted as the measurable indicator to assess the interaction.

TO THE QUESTION OF RESPONSIBILITY FOR TORTURE IN THE RUSSIAN FEDERATION

2020 ◽  
Vol 10 (2) ◽  
pp. 103-106
Author(s):  
ASTEMIR ZHURTOV ◽  
Keyword(s):  
Human Rights ◽  
Russian Federation ◽  
Large Scale ◽  
Human Life ◽  
International Standards ◽  
World Community ◽  
The World ◽  
Long Time ◽  
Protection Of Human Rights ◽  
The Russian Federation

Cruel and inhumane acts that harm human life and health, as well as humiliate the dignity, are prohibited in most countries of the world, and Russia is no exception in this issue. The article presents an analysis of the institution of responsibility for torture in the Russian Federation. The author comes to the conclusion that the current criminal law of Russia superficially and fragmentally regulates liability for torture, in connection with which the author formulated the proposals to define such act as an independent crime. In the frame of modern globalization, the world community pays special attention to the protection of human rights, in connection with which large-scale international standards have been created a long time ago. The Universal Declaration of Human Rights and other international acts enshrine prohibitions of cruel and inhumane acts that harm human life and health, as well as degrade the dignity.Considering the historical experience of the past, these standards focus on the prohibition of any kind of torture, regardless of the purpose of their implementation.

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