A method to prevent over-level tripping of power supply system in coal mine

Abstract

The present invention provides a method for preventing the tripping of a power supply system in a coal mine. The anti-overlapping protection module is embedded in the relay protection device of each power supply line under the coal mine. Each anti-overlapping protection module performs independent anti-overlapping protection discrimination, specifically: When the anti-override protection module F2 at any power supply node detects the fault signal of the power supply line, the anti-override protection module F2 sends a level 1 blocking signal to the upper-level anti-override protection module F3 to prevent the upper-level anti-override protection module F3 from tripping and expanding Fault range; at the same time, the trip delay of the anti-overstepping protection module F2 is dynamically adjusted, that is, it is dynamically adjusted according to whether it receives the blocking signal from the lower level anti-overstepping protection module F1, and according to the level of the received blocking signal Tripping delay, so as to achieve selective tripping and avoid skipping tripping.

Description

technical field [0001] The invention belongs to the technical field of coal mine power supply, and in particular relates to a method for preventing a coal mine power supply system from leapfrog tripping. Background technique [0002] With the development of my country's coal enterprises in the direction of large-scale, safe and automatic, the reliability of coal mine power supply system has become an important indicator of mine safety and production. Due to the particularity of the operating environment and equipment of the underground power supply and distribution network in coal mines, power supply failures such as short circuit, overcurrent, leakage, and power failures caused by voltage fluctuations will occur in the underground power supply and distribution system of coal mines. When the power supply system fails, the power supply system often occurs the phenomenon of over-level tripping. The over-level tripping phenomenon refers to: when the power supply system fails, t...

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Problems solved by technology

[0005] However, when this technology is applied to the coal mine underground power supply system, it still cannot completely solve the problem of power supply leapfrog tripping, and it will also reduce the reliability of underground power supply. The reasons are as follows:

[0006] (1) The system relies too much on the optical fiber communication channel. Once the optical fiber is interrupted, the protection function of the underground feeder lines will be lost, seriously affecting the safety of power supply

Due to the characteristics of underground operations in coal mines, underground optical fiber interruptions occur from time to time, so the power supply anti-overstep monitoring system based on this method cannot play a good role

[0007] (2) The system is based on synchronous sampling technology, which requires that the sampling data must be transmitted to the ground protection host in real time. Since the data transmission channel is a public optical fiber network, the network load is relatively large, and data transmission delays, network congestion or fiber interruptions often occur. Directly affect the timeliness of relay protection host protection judgment, affect the safety of power supply

[0008] (3) Underground power supply in coal mines mostly adopts double-circuit or multi-circuit power supply methods, and the power supply methods of each mine are different, so the relay protection host based on the above technology needs to compile corresponding relay protection according to different mines and different power supply methods Algorithm program, program logic is not universal, it is difficult to guarantee the reliability of relay protection

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