Zero-sequence backup protection setting method for ultra-high voltage transmission line

Abstract

The invention provides a zero-sequence backup protection setting method for an ultra-high voltage transmission line. The method comprises the following steps of: (1) configuring zero-sequence backup protection in a four-section form, deleting a zero-sequence backup protection I section and a zero-sequence backup protection section II, and reserving a zero-sequence backup protection section III and a zero-sequence backup protection section IV; (2) dividing the zero-sequence backup protection section III into a reference-side zero-sequence backup protection section III and a non-reference-side zero-sequence backup protection section III and respectively performing setting by utilizing a reference side; and (3) dividing the zero-sequence backup protection section IV into a reference-side zero-sequence backup protection section IV and a non-reference-side zero-sequence backup protection section IV and respectively performing setting by utilizing the reference side, wherein the reference side refers to any station end, of which an opposite station end adopts optical differential protection for all outgoing lines, on the transmission line. On the premise of no increase of the security risk of a power grid, the adaptability of a constant value to power grid change is improved, the protection constant value regulation caused by coordinating with constant value regulation is reduced and the workload of the setting calculation is greatly reduced simultaneously.

Description

technical field [0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to a setting method for zero-sequence backup protection of an ultra-high voltage line. Background technique [0002] Relay protection is one of the most important secondary devices in the power system, and it plays an extremely critical role in the safe and stable operation of the system. Line protection is used to automatically and quickly cut off the faulty line and isolate the fault after a fault occurs in the power grid, so as to ensure the safety of people and equipment and the normal operation of the non-faulty part. The main protection of the line trips the circuit breaker without delay when there is a fault, cuts off the line, and isolates the fault. The back-up protection of the line is used to trip the circuit breaker of this line or other lines to isolate the line fault when the main protection of the line fails or the circuit b...

AI Technical Summary

Problems solved by technology

Second, with the rapid development of the power grid, the structure and operation mode of the power grid are changing extremely rapidly. The complex setting principles make the setting calculation of the backup protection very difficult. Insufficient sensitivity has become a hidden danger to the safety of the power grid

[0004] Therefore, the current zero-sequence backup protection method restricts the flexible adjustment of the power grid operation mode, the mismatch between the protection settings, and the frequent changes of the settings bring unpredictable potential risks to the system, and also greatly increase the adjustment. Calculator Workload

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