Single-end diagnosis method for ultra-high-voltage direct current transmission line breakdown based on transient monitoring

Abstract

The invention relates to the field of power systems, in particular to a single-end diagnosis method for an ultra-high-voltage direct current transmission line breakdown based on transient monitoring.The single-end diagnosis method comprises the following steps that a voltage and a current at the line measurement point are obtained in real time, and a voltage frequency band transient component anda current frequency band transient component are obtained through filtering; a transient impedance change value and the transient power are calculated; when the transient impedance change value is less than a threshold value, a forward breakdown is judged; when the transient impedance change value is greater than the threshold value, a reverse breakdown or no-breakdown is judged; when the forwardbreakdown is diagnosed, if the transient power is greater than a threshold value, the direct current transmission line breakdown is judged; and if the transient power is less than the threshold value, a forward region external breakdown is judged. Through the single-end diagnosis method, the following effects that the transient impedance change value and the transient power are matched, the single-end diagnosis method is high in reliability, simple in criterion and convenient to calculate for diagnosing the direct current transmission line breakdown, and the breakdown type of the ultra-high-voltage direct current transmission line can be distinguished accurately and reliably can be achieved.

Description

technical field [0001] The invention relates to the field of power systems, in particular to a single-end fault diagnosis method for ultra-high voltage direct current transmission lines based on transient quantity monitoring. Background technique [0002] The UHV DC transmission system has the obvious advantages of large transmission capacity and long distance. It has become the link of large-scale regional power grids and the key support system for the future construction of the global energy Internet. The reliability of UHVDC transmission line operation directly affects the safety and stability of DC system and interconnected AC system. However, the spanning area of ​​UHVDC transmission lines is larger than that of traditional HVDC lines, and its operating environment is complex and changeable, and the probability of failure is higher. Due to the huge length of UHVDC transmission lines, for fault diagnosis, the attenuation effect of long DC lines on fault characteristic q...

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This method relies on the simulation system to establish a large number of samples. When the actual system pa

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