Circuit protection order component phase selectiing method using both end information

Abstract

The present invention relates to a circuit protecting order component phase selecting method adopting two-end information. First, synchronous samplings of the phase current of the own side and the opposite side of the circuit are performed in a preset sampling speed, and the sampling value of the phase current of the opposite side is transmitted to the own side; then, the differential current vectors of each phase of said sampling result is calculated and the positive-sequence vector, the negative-sequence vector and the zero- sequence vector I1d, I2d, I3d are extracted using the A phase as the standard phase; the negative-sequence vector and the zero- sequence vector of the differential current are compared: -90 DEG 1.5*[1d] , it is the single-phase groud fault; or, it is the two-phase ground fualt. The method adopts a differential current to performe judging, and the principle is simple and reliable and is not influenced by the running mode of the system. The device has a high sensitivity and can select phase correctly when a conversion fault occurs.

Description

technical field The invention belongs to the technical field of electric power system automation, and relates to a phase selection method for line protection sequence components using double-terminal information. Background technique When a fault occurs on the high-voltage or extra-high-voltage transmission line of the power system, the method of single-phase reclosing is widely used in the high-voltage system of our country. Due to the need for phase-selection tripping, the phase-selection element becomes an important element in the high-voltage protection device. Traditional phase selection elements can only be judged by single-ended voltage and current. Generally, there are phase selection elements for sudden change in phase current difference, impedance phase selection elements, and sequence component phase selection elements for single-ended quantities. These phase selection elements are only The use of single-ended quantities is often greatly affected by the operatin...

AI Technical Summary

Problems solved by technology

At present, the method of segmenting the sequence current and comparing the measured impedance is used as a phase selection element during the oscillation blocking period. During the oscillation blocking period, the measured impedance (especially the non-fault phase) is greatly affected by the system oscillation, and the measured impedance comparison is an auxiliary element. Single-phase grounding will be misjudged as two-phase short-circuit grounding fault, and two-phase short-circuit grounding will be misjudged as single-phase grounding, and its ability to withstand transition resistance is also very poor, which is a major hidden danger in the current high-voltage transmission line protection