Synthetical leakage-selection module for longitudinal and horizontal timing sequence identification of industrial and mining low-voltage electric network

Abstract

The invention provides a synthetical leakage selection module for the longitudinal and horizontal timing sequence identification of an industrial and mining low-voltage electric network on the basis of three invention patent achievements, i.e. ZL02110276.7, ZL200510042067.2 and ZL200510044820.1, aiming at the special situation and the actual demand of an electricity leakage protection system of the industrial and mining low-voltage electric network. The synthetical leakage-selection module can not only ensure the leakage selection of a feeder to be quick and accurate, but also distinguish three-phase symmetrical electricity leakage and single-phase electricity leakage, and can also separately display the single-phase electricity leakage of a bus and final check back-up protection no matterwhether the low-voltage electric network has zero sequence reactor compensation or not and whether a zero sequence reactor is in an undercompensation state or an overcompensation state or not.

Description

technical field [0001] The invention belongs to the fields of power grid fault detection, relay protection and electrical safety, and in particular relates to a vertical and horizontal time sequence identification comprehensive leakage selection module for industrial and mining enterprises whose neutral points are not directly grounded. Background technique [0002] Low-voltage power grids in industrial and mining enterprises are usually radial, or tree-like. The outgoing line from the low-voltage side of the power transformer first passes through a main switch to the busbar, and then passes through each sub-switch to form multiple branch feeder lines. Before the 1980s, my country's mine low-voltage power grid only installed a non-selective leakage protection device at the main switch, such as the JY-82 leak detection relay. Detect the fault and act on the tripping of the main switch, so that the entire low-voltage power grid will be completely blacked out; in order to avoid...

AI Technical Summary

Problems solved by technology

Before the 1980s, my country's mine low-voltage power grid only installed a non-selective leakage protection device at the main switch, such as the JY-82 leak detection relay. Detect the fault and act on the tripping of the main switch, so that the entire low-voltage power grid will be completely blacked out; in order to avoid gas explosions, the relevant "Regulations" stipulate that power transmission is not allowed until the leakage fault point is found and cut off

According to the above three invention patents, the applicant was able to develop the horizontal "centralized leakage selection module" and "centralized leakage selection device" for each feeder line of the mine low-voltage power grid, but there are also two shortcomings here; one is the feeder line leakage protection action time It only achieves less than 80ms, and has not yet achieved less than 30ms. Another disadvantage is that the total leak detection protector located at the power inlet end can only do simple vertical backup protection, and cannot further detect leakage faults according to fault categories and fault areas. Segmentation

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