Keywords:: Downhole; unattended substation; power automation; Monitoring system.
1. Background
This study is based on the research of the underground unattended substation power monitoring system technology of Malan Mine, which is developed on the basis of surface integrated automation technology, and is also a monitoring and monitoring equipment for the power supply system based on the actual conditions of the mine. The underground unattended substation power monitoring system technology provides protection and monitoring functions for the underground power supply safety, and reflects the underground situation to the underground through reliable signals, so that the underground technicians can clearly and accurately judge the underground power supply situation and ensure the power supply safety of the underground power supply system. Therefore, in May 2017, underground power monitoring substations were installed in the underground substation of Malan Mine, the coal substation of the Nanxia Group, the South Wing Substation, the South No. 5 Substation, the Majiakou Substation, the South No. 7 Substation, the South No. 6 Substation, the North Sanxia Coal Substation, and the North Wing Substation, and achieved good results, effectively ensuring the safety and reliability of the underground power supply system.
2.1. Rated working voltage and input apparent power of the whole machine.
2.2. The transmission port of the switch or monitoring substation.
1) The number of transmission ports is 2.
3) The connection form is SC.
5) Upper limit of transmission distance. 10km (transmit power - 13 3dBm, receive sensitivity - 28dBm, using MGTSV4B mine single-mode fiber optic cable; The total number of optical fiber contacts is 22, including 10 hot fusion contacts, 10 cold fusion contacts, and 2 active connection points).
The transmission port (intrinsic safety) of the high-voltage power distribution device (built-in ZBT-11 high-opening integrated protector) of the PBG type mine flameproof and intrinsically safe permanent magnet mechanism is as follows.
2) Transmission mode: master-slave, half-duplex, RS485.
4) Transmission distance. 1km (using mhyvr cable or mhyvp cable, the wire cross-section is not less than 1.)5mm2）。
2.4. The transmission port of the vacuum feed switch.
1) The number of transmission ports is 2 (P5 and P6 ports).
3) The data transmission rate is 9600bps.
5) Monitor capacity caps. Each transmission port can be connected to 8 KJZ16R mine flameproof and intrinsically safe vacuum feed switches.
1) The number of transmission ports is 1 channel and 2 fibers (P3 port, which can be changed to RS485 electrical transmission).
3) The connection form is single-mode and SC.
5) Upper limit of transmission distance.
2.6. The alarm sound is strong.
2.7**Signal input port.
2.8. Backup battery parameters.
2.9 display range.
2) Single-phase current. 0 630A (overcurrent 120 ); Single-phase voltage shown: 0 1140V (overvoltage 120).
The current and voltage transmission error of the high and low voltage protector is not greater than 05％（f.s.）。Underground power monitoring substations have been installed in the underground substation of Malan Mine, the coal substation of the Nanxia Group, the coal substation of the South Wing Substation, the South No. 5 Substation, the Majiakou Substation, the South No. 7 Substation, the South No. 6 Substation, the North Sanxia Group Coal Substation, and the North Wing Substation. Through practice, it is found that the power monitoring system of the underground unattended substation has the following functional characteristics: It has the function of two-way communication with the host computer; It has the function of two-way communication with high and low voltage protector and working status display; It has the current and voltage values collected by the high-voltage protector and the low-voltage protector; , with the opening and closing status of high-voltage protection and low-voltage protection; It has the functions of warning alarm and accident alarm, and the report type is sound alarm; The power monitoring substation can be used with a special remote control, and through the remote control, the command information can be directly issued to the high and low voltage protector. At present, the above substations can realize remote control, remote adjustment, remote signaling, telemetry and remote vision in the power dispatching center.
3.1. Application and economic benefits.
3.2. Social benefits.
1) Reduced staff and increased efficiency. Realize the unmanned underground substation, and each substation can save more than half of the labor.
3) It is convenient to distract from power statistics and system operation. By reading and printing hourly, daily, monthly and other reports of electricity and operation, the operation of the power supply system is analyzed, so as to provide a basis for improving the level of power supply management.
5) It can realize rapid fault diagnosis and ensure the real-time, certainty and reliability of control.
The system provides a variety of protection monitoring and control functions for the underground power supply system, and extends the monitoring and control to the surface power dispatching center through reliable underground and underground communication, so that the surface duty personnel can clearly understand the power supply status of the underground power grid, and can transform the underground fixed duty mode into a small number of people to inspect the mode. Since the installation of underground power monitoring systems in various substations of Malan Mine, the power supply has become more stable and reliable. Lay the foundation for the realization of unmanned duty in underground substations. At the same time, it has a very broad application prospect in the application of underground power automation in coal mines.
5.1 Overview.
ACREL-2000 power monitoring system adopts hierarchical distributed design, which can be divided into three layers: station control management layer, network communication layer and field equipment layer, and the networking mode can be standard network structure, optical fiber star network structure, optical fiber ring network structure, according to the user's electricity scale, electrical equipment distribution and floor area and other aspects of information comprehensive consideration of networking.
Figure 5: Networking mode of power monitoring system.
5.2.1 Real-time monitoring.
5.2.2 Detailed electrical parameter query.
5.2.3. Run the report.
5.2.4. Real-time alarms.
5.2.5 Historical Event Query.
5.2.6. Electric energy statistics report.
In order to ensure the safe and stable operation of the system, Acrel-2000 power monitoring system has set up a user rights management function. Unauthorized operations (e.g. remote control, database modification, etc.) can be prevented through user rights management. It can define the login name, password and operation authority of different levels of users to provide reliable security guarantee for system operation, maintenance and management.
5.2.8 Power quality monitoring.
The display page displays the number of substations, transformers, monitoring points and other general information, equipment communication status, power consumption analysis and event records. The home page displays the number of transformers, the number of circuits, active power, reactive power, power consumption, event records and other general information of the station, and can switch to the interface that needs to be viewed through real-time monitoring, transformer, communication, and **.
The Device Data page displays the electrical parameter data and curves for each device.
5.3 Related Products.
6 Epilogue
References. 1] Wang Jinhua. Research and application of unattended substation technology in coal mine JJournal of Mine Automation,2015,41(5):100-103
3] Smart Grid User-end Power Monitoring, Power Management, Electrical Safety (Product **Manual).2023.Version 01.
4] Enterprise Microgrid Design and Application Handbook. 2022.05 edition.
About author:Yi Yunheng, male, working in Ankerui Electric Co., Ltd., has been engaged in the power industry for a long time.