The Solution for Malfunction of the Leakage Protection System Caused by Mine-Used Converter

2014 ◽  
Vol 912-914 ◽  
pp. 1481-1484
Author(s):  
Yan Wen Wang ◽  
Hai Hong Li ◽  
Da Wei Wang ◽  
Zheng Fan
Keyword(s):  
Power System ◽  
Coal Mine ◽  
Protection System ◽  
Normal Operation ◽  
Coal Production ◽  
Actual Situation ◽  
Matlab Simulation ◽  
Zero Sequence ◽  
Working Principle ◽  
Isolation Transformer

The leakage protection system usually trends to make a misjudgment and tripping in normal operation after applying the converter in the coal mine power system. This seriously affects the safety in coal production. Based on the research of the structure and working principle of the converter, it has obtained the definite reason for the converter interfere the leakage protection system. It is the higher harmonics and pulses that generate the zero sequence current through the ground capacitance. Combined with the actual situation in coal mine, it has proposed two corresponding solutions: one is adding the isolation transformer in the output lines of the converter; another is modifying criterion of the leakage protection system. Both methods have their own characteristics, and have verified the feasibility of the methods through the MATLAB simulation.

Design of Ultracapacitor-Battery Composite Power System for Coal Mine Trackless Rubber Tyre Electric Vehicle

2014 ◽  
Vol 490-491 ◽  
pp. 1116-1119
Author(s):  
Chuan Wei Zhang ◽  
Ming Yu Wang ◽  
Ying Ying Wan
Keyword(s):  
Power System ◽  
Electric Vehicle ◽  
Coal Mine ◽  
Scientific Basis ◽  
Working Principle ◽  
Driving Range ◽  
Technical Basis ◽  
Composite Power System

This paper introduces the characteristics of ultracapacitor, designs the ultracapacitor-battery composite power system of coal mine trackless rubber tyre electric vehicle. Then the composite power system’s structure and working principle are discussed. Moreover, the driving range of coal mine trackless rubber tyre electric vehicle is improved, and this provides the scientific basis and technical basis for coal mine trackless rubber tyre electric vehicle’s application has a certain value.

The Research of New Selective Leakage Protection Device Based on Additional DC and Zero-Sequence Power

2013 ◽  
Vol 457-458 ◽  
pp. 1185-1188
Author(s):  
Yan Wen Wang ◽  
Yin Sheng Wang
Keyword(s):  
Computer Simulation ◽  
Theoretical Analysis ◽  
Coal Mine ◽  
Protection System ◽  
Protection Device ◽  
Zero Sequence ◽  
Power Direction

By theoretical analysis and computer simulation,this paper has successfully solved the compatibility problembetween the Leakage protection with additional DCand zero-sequence power direction Leakage protection, and realized the goal of the two different ways of leakage protection sharingone set of electrical leakage protection system.This paper focuses on the basic components of "EDS-336/660 centralized-distributed selective leakage protection system"and its practical usage in Lvjiatuo Coal Mine.

Research of Integrated Distribution Scheme of Reactive Power Compensation Based on SVG for Coal Mine Power System

2013 ◽  
Vol 457-458 ◽  
pp. 1585-1588
Author(s):  
Yan Wen Wang ◽  
Dan Lu
Keyword(s):  
Power System ◽  
Power Factor ◽  
Coal Mine ◽  
Power Distribution ◽  
Reactive Power ◽  
Low Voltage ◽  
Reactive Power Compensation ◽  
Matlab Simulation ◽  
Long Distance ◽  
Distribution Scheme

Aiming at the situation of the low power factor of coal mine power system, this paper puts forward an integrated distribution scheme of reactive power compensation based on SVG. In this paper, not only the disadvantageous influences of reactive power of coal mine power network are analyzed, but also the working principle and advantages of SVG are introduced. This paper proposes a distribution scheme of three-level reactive power compensation, which is to compensate in the sides of high voltage, high-low voltage power distribution and the long-distance high-power loads. According to the results of theoretical calculation and MATLAB simulation, the scheme can reduce the power loss and increase the power factor, so the power quality of coal mine can be improved.

scholarly journals Adaptive Differential Protection System for Microgrid

2021 ◽  
Vol 9 (VII) ◽  
pp. 2364-2371
Author(s):  
Rahul Kumar Bhardwaj
Keyword(s):  
Power System ◽  
Transmission Loss ◽  
Green Energy ◽  
Protection System ◽  
Differential Protection ◽  
Renewable Energy Resources ◽  
Matlab Simulation ◽  
Protection Scheme ◽  
Simulation Based ◽  
Electric Loads

Microgrids are the small version of power system which grants us the integration of distributed generation resources to insure the facilities to the remotely located electric loads as well as have so many advantages over traditional power system like reduced transmission loss, green energy solution and proper use of renewable energy resources. However the resilience offered by microgrid is inconvenient if it is not be able to protect properly in case of any disturbance occurs which is very common in microgrid due to load dynamics. Protective devices used in traditional power grid cannot actually protect microgrid due to variable loads and different fault levels at grid connected modes and islanded modes. The available research about this concern has not been very successful, therefore options like distance, directional over current and differential relay remains effective protection scheme from present standard. Even though these relays are very useful in power system but their effectiveness for microgrid is yet to be analyzed. This paper is presenting the MATLAB simulation based analysis for differential relay type adaptive protection system by taking a complex microgrid model and generating various fault and generation capacities and analyzing it. In this paper different scenarios has been discussed where differential relay seems to be better than distance and directional over current relay protection scheme.

Chances and Threats of Hard Coal Mining Development in Poland – The Results of Experts Research/Szanse I Zagrożenia Dla Rozwoju Górnictwa Węgla Kamiennego W Polsce – Wyniki Badań Eksperckich

2014 ◽  
Vol 59 (2) ◽  
pp. 395-411 ◽  
Author(s):  
Józef Dubiński ◽  
Marian Turek
Keyword(s):  
Coal Mining ◽  
Present Situation ◽  
Hard Coal ◽  
Coal Production ◽  
Actual Situation ◽  
Mining Sector ◽  
Energy Carriers ◽  
Hard Coal Mining ◽  
Adverse Influence ◽  
Other World

Abstract The actual situation of hard coal mining in Poland has been presented. In particular, these factors, which have impact on the competiveness of mining sector were highlighted and need of its improving has been stressed. Outlining present situation of hard coal mining an attention was paid to its specific threats. The primary analytical material is based on the results of questionnaire conducted among 92 specialists and experts from the mining sector. The questions were related to chances and threats for development of hard coal mining in Poland. The factors determining them were grouped in such domains as economy, technology, geology, social and law aspects. Moreover, the special attention was paid to the problem of increasing and high costs of coal production which constitute significant threat for the financial and economic situation of the mining enterprises. Also the adverse influence of these high cost on the competitiveness of Polish hard coal with other world producers and with other energy carriers was emphasized. The conclusions summarize the achieved results of analysis.

Sign in / Sign up

Export Citation Format

Share Document