Power transmission line single-ended fault location method based on variable traveling wave recognition time window

Abstract

The invention discloses a power transmission line single-ended fault location method based on a variable traveling wave recognition time window. According to the method, through online estimation of opposite-end system impedance and establishment of an improved distribution parameter method, the irregularity of error distribution of a conventional method is effectively improved, and the feasibility of establishing a combined location algorithm according to power frequency quantity location error is promoted. A variable fault distance window is calculated according to different fault conditions and error rules, the corresponding time area of fault reflected traveling waves is targeted, and thus the variable reflected traveling wave recognition time window is defined. Based on the variable time window, the bus wiring mode of the local end and the opposite end of measurement, influences of adjacent bus reflected waves and other factors are comprehensively considered, and a reflected wave recognition method and a location method in the variable time window are established through the traveling wave method. Simulation verification results show that the reliability level of the combined location method is improved through the method, and the method has high fault location precision and certain engineering application value.

Description

technical field [0001] The invention relates to the field of fault location, in particular to a single-end fault location method of a transmission line based on a variable traveling wave identification time window. Background technique [0002] Compared with double-ended ranging, single-ended ranging is not restricted by factors such as communication conditions, economic conditions, and management authority. Its inherent advantages make single-ended ranging have broad development prospects. However, there are still some problems in single-ended ranging: due to theoretical limitations, the power frequency measurement method cannot fundamentally eliminate the influence of the boosting current at the opposite end, and the actual application error is relatively large; the traveling wave method is theoretically not affected by system operation mode, fault Due to the influence of transition resistance, the distance measurement accuracy is higher than that of the power frequency me...

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Problems solved by technology

However, there are still some problems in single-ended ranging: due to theoretical limitations, the power frequency measurement method cannot fundamentally eliminate the influence of the boosting current at the opposite end, and the actual application error is relatively large; the traveling wave method is theoretically not affected by system operation mode, fault Due to the influence of transition resistance, the distance measurement accuracy is higher than that of the power frequency method, but the key of the traveling wave method is the accurate identification of the traveling wave refraction and reflection wave. However, the traveling wave waveform in the engineering site is complex, and it is difficult to identify the wave head. Invalid wave head identification will lead to errors targeting results for

[0004] 1. Use the polarity relationship to identify the nature of the reflected wave, but the polarity relationship is limited by the type of field bus

[0005] 2. The single-ended traveling wave ranging method using the initial reverse polarity traveling wave for the "three types of" bus structure, the application range of this method is limited

[0007] 4. Use the single-ended impedance method to screen multiple results of the traveling wave method, and correct the fault location results near the midpoint of the line based on the error law of the impedance method. In the case of complex fault conditions on site, it is difficult to follow a certain distance measurement accuracy by the impedance method. law

[0008] 5. Utilize the ranging result of the impedance method and the 10% error of the impedance method to limit the identification range of the reflected wave at the fault point, but it is difficult to detect the reflected wave at the fault point when there are two outgoing lines at the measuring end, and the 10% error range is not conducive to the small error Fault conditions can effectively screen out interference waves

[0009] It can be seen that the combined fault location method has strong theoretical and engineering feasibility, but it is also limited by the bus connection mode and the validity of the limited range of traveling wave reflection

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