Self-adaptive circuit protection fault location method and system

Abstract

The invention discloses a self-adaptive circuit protection fault location method and system. The method comprises the following steps of when a circuit has a fault, obtaining three-phase current magnitude and three-phase switch position information; calculating a positive sequence current component, a negative sequence current component and a zero sequence current component; judging the operationmodes at two sides of the circuit; determining the fault location method; performing fault location calculation according to the determined fault location method; and obtaining the fault location result. When one side is in a no-load charging mode, a single-terminal location method is used; when the two ends are both in normal operation, if both of the two sides meet the positive sequence currentavailable discrimination condition, a double-terminal location method is built by a sequence network diagram based on a positive sequence loop; if any one side does not meet the positive sequence current available discrimination condition, and any one side meets the zero sequence current available discrimination condition, the result shows that one side is a weak power supply side, and at the moment, a double-terminal location method is built by using the sequence network diagram based on a zero sequence loop; and if all of the conditions are not met, the result shows that the double-terminallocation is not available, and the single-terminal location method is used.

Description

technical field [0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to an adaptive line protection fault ranging method and system. Background technique [0002] The fault location module is an important logic in the line protection device, and the accuracy of the fault location directly affects the efficiency of a device troubleshooting. [0003] The fault location algorithm in the existing line protection is mainly based on the simple application of the double-ended ranging method and the single-ended ranging method. Under the various complex operation modes and fault modes existing in the existing power system, the adaptability is slightly Insufficient, mainly reflected in the fact that when an internal fault occurs in the weak feed mode, the positive sequence component of the current at the protection installation on the weak feed side is very small, and the simple use of the sequence network diagram ba...

AI Technical Summary

Problems solved by technology

[0003] The fault location algorithm in the existing line protection is mainly based on the simple application of the double-ended ranging method and the single-ended ranging method. Under the various complex operation modes and fault modes existing in the existing power system, the adaptability is slightly Insufficient, mainly reflected in the fact that when an internal fault occurs in the weak feed mode, the positive sequence component of the current at the protection installation on the weak feed side is very small, and the simple use of the sequence network diagram based on the positive sequence loop to construct a double-terminal ranging method will result in Large calculation errors lead to inaccurate distance measurement results; for non-ground faults in non-weak feed-in areas, the zero-sequence component of the current at the protection installation on both sides is very small, and a double-ended circuit built based on the sequence network diagram of the zero-sequence circuit is simply adopted. The distance measurement method will also produce large calculation errors, resulting in inaccurate distance measurement results

Images