Research of Comprehensive Protection Device in Underground Coal Mine Lighting Power Grid

2013 ◽  
Vol 329 ◽  
pp. 304-307
Author(s):  
Xu Dan
Keyword(s):  
Real Time ◽  
Coal Mine ◽  
Short Circuit ◽  
Power Grid ◽  
Protection System ◽  
Protection Device ◽  
Long Distance ◽  
Cable Insulation ◽  
Underground Coal Mine ◽  
Existing Problems

In view of the present our country underground lighting power grid comprehensive protection device existing problems, this paper introduces a DSP-based long distance lighting comprehensive protection device. Short-circuit protection using adaptive random setting mode. Leakage protection using additional DC measurement theory.The device has the function of cable insulation level, the network current is monitored real-time and grid parameters are displayed in turn, which make the protection system more perfect and reliable.

Design of Underground Gas Concentration and Humidity Monitoring System Based on RS-485

2014 ◽  
Vol 989-994 ◽  
pp. 2962-2964
Author(s):  
Yue Hong Long
Keyword(s):  
Real Time ◽  
Coal Mine ◽  
Humidity Sensor ◽  
Long Distance ◽  
Monitoring Point ◽  
Underground Coal Mine ◽  
Gas Concentration ◽  
Master Station ◽  
Upper Computer ◽  
Humidity Monitoring

In order to achieve long distance monitoring of gas concentration and humidity underground coal mine,a new monitor of gas concentration and humidity,which contains upper computer,master station and a lot of monitoring points,is designed.Every monitoring point is consisted of gas concentration sensor MJC4/3.0L and humidity sensor HS1101,which is used to conveys the data to master station by RS-485,again by RS-485 transmitted to the upper computer and it realizes the real-time monitoring of gas concentration and humidity undereground coal mine.

scholarly journals Optimization Strategy of SVC for Eliminating Electromagnetic Oscillation in Weak Networking Power Systems

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3489
Author(s):  
Huabo Shi ◽  
Xinwei Sun ◽  
Gang Chen ◽  
Hua Zhang ◽  
Yonghong Tang ◽  
...  
Keyword(s):  
Parameter Optimization ◽  
Short Circuit ◽  
Power Grid ◽  
Oscillation Mode ◽  
Voltage Regulation ◽  
Optimization Strategy ◽  
Long Distance ◽  
Large Power ◽  
Electromagnetic Oscillation ◽  
Long Distance Transmission

The central Tibet AC interconnection project (CTAIP), which connects the Tibet power grid and the Sichuan power grid through a long distance transmission line of more than 1400 km, has a significant problem of voltage regulation. In order to improve the voltage regulation performance, six sets of ±60 Mvar static VAR compensators (SVC) were installed in the CTAIP. However, the SVCs may lead to electromagnetic oscillation below 50 Hz while improving voltage regulation capability. In this paper, the electromagnetic oscillation modes and the sensitivity of control parameters of SVC are analyzed. Then, the characteristics and influencing factors of the oscillation are discussed. It was found that there is an inherent electromagnetic oscillation mode below 50 Hz in the ultra-long distance transmission system. The employ of SVCs weaken the damping of this mode. Large proportional gain and integral gain (PI) parameters of SVCs can improve the voltage regulation performance, but weaken the electromagnetic oscillation mode damping. Therefore, a suppression method based on SVC PI parameters optimization is proposed to damp the oscillation. The essential of this method is to use the rising time of voltage response and setting time of SVCs as performance indicators of voltage regulation, and take the damping level of the electromagnetic oscillation mode as the performance index of SVC electromagnetic oscillation suppression ability. Combining the two indicators to form a comprehensive optimization index function, an intelligent optimization algorithm is applied. The process of SVC parameter optimization and the steps of multi-SVC parameter optimization in large power grids is proposed. Finally, PSCAD and real-time digital simulation (RTDS) simulation results verified the correctness of the proposed method. The optimization strategy was applied to CTAIP. The artificial grounding short circuit experimental results proved the effectiveness of the proposed strategy.

Research of Adaptive Line Selection Leakage Protection Based on DSP in Mine

2011 ◽  
Vol 143-144 ◽  
pp. 14-18
Author(s):  
Dan Xu ◽  
Zhan Zhang
Keyword(s):  
High Voltage ◽  
Coal Mine ◽  
Power Supply ◽  
Power Grid ◽  
Protection System ◽  
Direct Power ◽  
Supply Condition ◽  
Line Selection ◽  
Phase Sensitive

In view of the present our country coal mine high-voltage power grid widely used 6kV or 10kV cable direct power supply condition. To describe a DSP-based adaptive line selection leakage protection program of high-voltage power grid. It adopts under-compensation, adaptive random tuning and phase-sensitive comparison to judge the fault branch and achieve selective leakage protection, and make the protection system more perfect and reliable.

Design of a System for Avoiding Over Tripping in Coal Mine Based on CAN Communication

2011 ◽  
Vol 143-144 ◽  
pp. 782-786
Author(s):  
Chang Sen Zhang ◽  
Kun Liu
Keyword(s):  
Coal Mine ◽  
Can Bus ◽  
Short Circuit ◽  
Underground Coal Mine ◽  
Real Application ◽  
Machine Communication

This paper presents a solution and design for avoiding over tripping in cases that short circuit happens underground coal mine. A method of multi-machine communication based on CAN bus is given to obtain selective short-circuit protecting. The design proposed in this paper can be easily realized and reach for demand in real application.

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.

Study on Preventing Override Trip System for High-Voltage Power Grid of Coal Mine Underground Based on the EtherCAT

2013 ◽  
Vol 273 ◽  
pp. 389-393
Author(s):  
Yu Mei Wang ◽  
Xu Yang ◽  
Hao Zhang
Keyword(s):  
High Voltage ◽  
Coal Mine ◽  
Power Supply ◽  
Power Supply System ◽  
Short Circuit ◽  
Power Grid ◽  
Supply System ◽  
Quality Requirements ◽  
Master Station ◽  
Short Circuit Fault

When the power supply system for coal mine underground take place a short circuit fault, multilevel switch often respond at the same time. And the existing comprehensive protector cannot satisfy the real-time and rapid quality requirements of preventing override trip system for high-voltage power grid of coal mine underground. So this paper put forward the research for comprehensive protector of preventing override trip based on the EtherCAT. This paper first analyzes the principle and characteristics of the EtherCAT technology; and then puts forward the overall scheme of preventing override trip system; Finally, study and design the slave station and master station of preventing override trip system based on the EtherCAT.

Protection System Design of Overload, Short Circuit and Three-Phase Imbalance for Electromagnetic Starter in Coal Mine

2014 ◽  
Vol 1049-1050 ◽  
pp. 726-731
Author(s):  
Qing Hua Mao ◽  
Hong Wei Ma ◽  
Wang Xing ◽  
Yu Liu ◽  
Min Zeng
Keyword(s):  
Coal Mine ◽  
Short Circuit ◽  
Protective Action ◽  
Protection System ◽  
Protection Method ◽  
Three Phase ◽  
Circuit Structure ◽  
Phase Sensitive ◽  
Structure Flexibility ◽  
Hardware Circuit

An intelligent protection system of electromagnetic starter in coal mine was designed. Its controller core is PLC LM3108K. The voltage rank of protection system is 660V and the electric current rank is 400A. It has protection functions for overload, short circuit, break phase and three-phase imbalance. The system achieved overload protection by using the method of inversing time overload. Greater the overcurrent is, Shorter the time of protective action is. The system achieved short circuit protection by using phase sensitive protection method, which improves sensitivity and reliability of short circuit protection. The system can display work status parameters and fault types timely by text LCD. It has the advantages of hardware circuit structure flexibility and automatically reset after fault relieved.

scholarly journals Study on Fault Analysis and early warning system of wind-induced disasters on transmission lines

2020 ◽  
Vol 194 ◽  
pp. 03016
Author(s):  
LIN Fanqin ◽  
JIA Ran ◽  
Yang Jingjing ◽  
CAO Huaming ◽  
LIU Hui ◽  
...  
Keyword(s):  
Wind Speed ◽  
Real Time ◽  
Transmission Lines ◽  
Early Warning ◽  
Early Warning System ◽  
Short Circuit ◽  
Power Grid ◽  
Warning System ◽  
Strong Wind ◽  
The Impact

Wind-induced disaster has become one of the most important disasters affecting the safe operation of power grid. In order to improve the effect of prevention and treatment of wind-induced disasters, it is very important to give early warning and real-time warning. Therefore, based on the climate characteristics of Shandong power grid, this paper presents the wind speed statistical law and the distribution characteristics of the number of days with strong wind. By analysing the mechanism of wind-induced disasters and combining the fault data of five years, the characteristics and rules of wind deviation and foreign short-circuit fault are obtained. On this basis, an early warning model of wind deviation based on the calibration of minimum air gap and the determination of maximum wind speed is established. At the same time, there is a short circuit model based on visual image information. Based on GeoServer platform, we will develop an early warning system for wind-induced disasters of transmission lines, which can provide real-time warning and early warning for wind-induced disasters. The application of the system can reduce the impact of wind damage on the transmission line, and effectively improve the operation reliability of the line.

scholarly journals Analisis Gangguan Arus Hubung Singkat Trafo Distribusi 48-PT-33-7 Menggunakan ETAP (Studi Kasus Di Perumahan PT. Badak NGL)

2020 ◽  
Vol 17 (2) ◽  
pp. 99
Author(s):  
Abdul Zain ◽  
Rifki Chairul Afwan
Keyword(s):  
Short Circuit ◽  
System Modeling ◽  
Power Grid ◽  
Short Circuit Current ◽  
Simulation Software ◽  
Protection System ◽  
Two Phase ◽  
Coordination Sequence ◽  
Short Circuit Analysis ◽  
Manual Calculation

The high frequency of short circuit current fault in power grid PT. Badak NGL Bontang in 2017 becomes a serious problem. One of them is the Short Circuit at Distribution Transformer 48-PT-33-7 which resulted in a feeder 48-FDR-33 trip and cut off the power to all connected loads. This research is conducted to know the value of short circuit current fault by manual calculation and compared with the simulation software ETAP 12.6 which made system modeling refers to real network configuration in the field. After that, ETAP conducted simulation and short circuit analysis in transformer 48-PT-33-7. The calculation result is known that the short circuit current value between manual calculation and ETAP simulation is relatively same, ie 553,8 A / 555 A (one phase to ground), 891,47A / 885 A (two phase), 918,16 A / 950 A (two phase to ground), 1029.41 A / 1022 A (three phases). From the simulation also known the coordination sequence of the protection system works properly when the fault occurs. So from these two results indicate that the installed protection system is in accordance with the standard in securing the power grid from short-circuiting current fault.

UHV AC Placement Selection Method Based on the Short Circuit Current Coordination

2015 ◽  
Vol 738-739 ◽  
pp. 1280-1284
Author(s):  
Lin Lin Yu ◽  
Yu Fei Rao
Keyword(s):  
Computational Analysis ◽  
Short Circuit ◽  
Power Grid ◽  
Short Circuit Current ◽  
Selection Method ◽  
Impact Point ◽  
Empirical Methods ◽  
Low Loss ◽  
Long Distance ◽  
Ac Transmission

UHV AC transmission has a high transmission capacity, long distance, low loss, covers save etc. significant advantages, so it’s widely used in our country. But the placement of the UHV which was sent to select still major use projects empirical methods. This method lacks clarity and systematic. Meanwhile, it is difficult to adapt to complex changes in the overall demand for power grid. This paper developed a UHV AC placement selection method based on short-circuit current coordination. According to UHV grid and nearby 500kV grid short-circuit current coordination constraint, unreasonable impact point sent plan was excluded so that greatly unnecessary computational analysis was reduced. This can quickly determine the placement of reasonable UHV AC transmission project plan.

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