A fault location method for HVDC transmission lines

A transmission line and fault distance measurement technology, which is applied in the direction of fault location and fault detection according to the conductor type, can solve the problem that the natural frequency is difficult to extract, and achieve the effect of improving accuracy

CN106019076BActive Publication Date: 2019-03-26XIAN UNIV OF TECH
5 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2019-03-26

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

The invention discloses a fault distance detecting method for a high-voltage DC transmission line. The method comprises a step 1 of acquiring the voltage positive electrode data and negative electrode data of both ends of a faulted line; a step 2 of filtering the acquired voltage positive electrode data and negative electrode data; a step 3 of decoupling the filtered data to obtain line mode voltage data; a step 4 of determining the time t1 and the time t2 when an initial travelling wave reaches both ends respectively; a step 5 of computing a fault distance coarse value d; a step 6 of computing a frequency band dk corresponding to a range from 0.9d to 1.1d; a step 7 of extracting an inherent frequency principal component fk from the frequency band dk; and a step 8 of computing a fault distance accurate value d1 by using the inherent frequency principal component fk extracted in the step 7. The fault distance detecting method solves a problem that it is difficult for a conventional inherent frequency fault distance detecting method to extract the inherent frequency because of mode aliasing, and increase fault distance detecting accuracy.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention belongs to the technical field of high-voltage direct-current transmission relay protection in electric power systems, and in particular relates to a fault distance measurement method for high-voltage direct-current transmission lines. Background technique

[0002] With the construction of a strong smart grid and the continuous development of the power system, high-voltage, long-distance, and large-capacity transmission lines play an extremely important role in the safe and stable operation of the power grid. However, HVDC transmission lines are generally long, and the terrain along the way is complex and the environment is harsh, which makes it extremely difficult to find line faults. Therefore, it is of great significance to study how to quickly and accurately locate faults in DC transmission lines.

[0003] At present, the fault location method of HVDC transmission lines is mainly the traveling wave method. Single-ended traveling wav...

Examples

Embodiment

[0079] The Cigre model of the International Conference on Large Power Grids is selected as the prototype, and a bipolar twelve-pulse HVDC DC transmission model is built on the transient simulation software PSCAD / EMTDC. The simulation model is as follows: Figure 8 shown. Single-pole grounding faults are set at 100, 400, 500, 700, and 900 km away from the rectifier side, and the fault transition resistances are 0Ω and 100Ω, respectively. Set the system to have a single-level ground fault at 1.5s, and the sampling rate is 10kHz.

[0080] 1) Single pole ground fault

[0081] For a single-pole grounding fault on a DC line, collect fault voltage data at both ends of the line, use the algorithm proposed in this application to obtain the time when the fault traveling wave reaches both ends of the line, the rough measurement value of the fault distance, the rough measurement range of the fault distance, and the natural frequency range, wavelet packet frequency band and natural frequ...