In the current daily production of coal mining enterprises, whether the electrical protection technology of power supply system equipment can be implemented smoothly will be directly related to the normal operation of life and business activities of coal mining enterprises and the life safety of operating personnel.This requires related technologies to continuously improve and improve the electrical protection technology of power supply equipment on the original basis, so as to make it gradually intelligent and automatic.In addition, in the electrical protection technology of power supply equipment, Chinese technicians should update their ideas and constantly innovate. Only in this way can we fundamentally guarantee the safe operation of electrical equipment and lay a solid foundation for the development of coal mining enterprises.
Currently coal mine electrical protection powered devices over-current, and earth leakage protection of the three types, various series of electrical protection devices and protective equipment along with the power electronics technology, micro-electronics technology, computer control technology and network communication technology and Constantly improved and improved.
1. Electrical protection of coal mine 6kV high voltage power supply equipment
Ground and mine general-purpose high-voltage switchgears used in ground substations and underground central substations. The general electrical protection is a relay protection device installed in a specially designed relay room or as a separate protective device screen. At present, the protection relays for high-voltage switchgear used in coal mines are mainly electromagnetic induction type. With the popularization and application of microprocessor protectors, the protection methods and protection equipment of coal mine sites have also broken through the traditional form.
The high-voltage explosion-proof power distribution device used in the substation mining substation and the fully mechanized mining face has a simple structure protection tripper and a microcomputer-based integrated protector with powerful functions and different performances. The use of the high-voltage integrated protector controlled by the microcomputer program in the underground has been welcomed by coal mine workers.
2. Electrical protection of low-voltage power supply equipment in coal mines
Most of the electrical protection devices for underground low-voltage equipment in coal mines are installed as plug-ins inside the switchgear, and cooperate with the main circuit electrical appliances to complete the protection function. A large number of low-voltage switches use DT3 electronic trip units, JDB or ABD8 motor integrated protectors, and DZZB integrated protectors.
3. Several new integrated protection devices in substation automation system
The rapid development of electrical control and protection, from thermal electromagnetic to electronic intelligent protection, from PCS, ACS, CCS, DCS systems to FCS fieldbus, has become systematic and intelligent. At present, the microcomputer protection in the power system has been widely used. The typical foreign models are SEL-279 and SEL-321 of the American SEL company, ALPS type of GE company, 7SA531 type microcomputer protection device of Siemens of Germany, etc. automatic protection systems have matured WXB series, NARI-RELAYS series RCS Group, Beijing DeWitt Group DVP-600 series, and the XJ Group, Nanjing Yin Tailai, Shaanxi Milky Way and so on; mine system in use There is also KJ67 of Beijing Shuncheng Electronics Co., Ltd., and KJ36 power monitoring system of Changzhou Automation Institute of Coal Research Institute.
4. Functions of new mine electrical protection devices
According to the requirements of Articles 455 and 457 of the Coal Mine Safety Regulations, the new intelligent integrated protection device can not only detect the conventional power parameters such as voltage, current, power and electricity on-line, but also has the conventional protection functions required by the regulations, and there are standards. The communication interface can realize the "four remotes" of the operation status of the key switchgear in the power grid, and provide support for power dispatching automation.
5. Suggestions for new comprehensive protection devices for mining
Substation integrated automation system will be gradually promoted and applied in coal mines. Due to the complexity of the types of downhole switchgear, the structure is diverse, the space is very narrow and it is necessary to detonate. Therefore, the new integrated protection device must be small in size and have a standard plug-in interface. The protection module should have the characteristics of excellent performance, high reliability, flexibility, convenient debugging and maintenance, good cost performance and multi-functionality. It adopts open software and hardware system, embedded distributed structure and multi-CPU parallel working mode, enriching man-machine dialogue function to ensure the safe operation of coal mine power supply equipment.