Wide-area wireless synchronous centralized multi-stage multi-terminal differential protection system and implementation method

Abstract

The invention relates to a wide-area wireless synchronous centralized multistage multi-terminal differential protection system and an implementation method. According to the invention, sampling synchronization is realized by sending a sampling synchronization instruction to each sensing execution unit through a main control unit in a wireless communication mode, each sensing execution unit is installed on a power supply line in a segmented mode according to a load equalization principle, each sensing execution unit sends electrical quantity calculated by synchronous sampling to the main control unit in a wireless communication mode, the main control unit calculates differential electric quantity, when the differential electric quantity reaches an action value, the main control unit sends adifferential action command to the sensing execution units, the sensing execution units execute action, and the main control unit sends the differential action command to the corresponding sensing execution unit, so that multi-stage multi-end differential protection of the power supply line is realized, and the reliability of differential protection is improved. According to the technical schemeprovided by the invention, unlimited-level multi-terminal differential protection of the same power supply line can be realized, and wide-area differential protection of different power supply lines erected on the same pole can also be realized.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a wide-area wireless synchronous centralized multi-stage multi-terminal differential protection system and its implementation method. Background technique [0002] At present, the differential protection of transmission lines mainly adopts the optical fiber differential protection method. In this method, one optical fiber differential protection is installed at both ends of the substation, and the simultaneous sampling at both ends is realized through optical fiber communication, and the differential current and braking current are calculated. When the action conditions are met, the switches at both ends of the line are tripped to realize the line protection function. For the differential protection of multi-terminal lines, multiple optical fiber communication interfaces need to be configured, which increases the complexity of hardware design and is...

AI Technical Summary

Problems solved by technology

For the differential protection of multi-terminal lines, multiple optical fiber communication interfaces need to be configured, which increases the complexity of hardware design, and is currently not feasible.

At the same time, this method cannot achieve differential protection for short-circuit faults between power supply lines erected on the same pole from different power supply directions

[0003] With the large-scale access of renewable energy to the distribution network, there are more and more grid structures with mixed operation of the AC distribution network and the DC distribution network. The distribution network with multiple power sources has a complex structure and variable operation modes. The multi-connection complex power supply network architecture and the power supply mode of erecting power supply lines with different power directions on the same pole lack effective protection methods. How to realize multi-terminal differential protection with unlimited levels in the AC-DC hybrid distribution network to improve detection and isolation of faults The accuracy of the protection of power supply equipment, shortening the power outage time, and overcoming the limitations of the differential protection at both ends of the transmission line have become the concerns of the power supply department. However, there are no corresponding research results and related reports.

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