Rapid calculation method of high-voltage/extra-high voltage direct current (DC) transmission line fault voltage traveling wave

Abstract

The invention discloses a rapid calculation method of a high-voltage / extra-high voltage direct current (DC) transmission line fault voltage traveling wave. The method comprises the following steps: acquiring phase-frequency domain fault point injection current I<f> and a system node voltage equation; acquiring a plurality of sampling values of mutual impedance between a DC transmission line side and a fault point; dividing the obtained frequency response into N sections along the F (omega) frequency axis, and setting the initial ranges of orders of all frequency bands to be (N<mink>, N<maxk>); calculating the error function E<k>=F(omega<k>)-F<*(k+1)> (omega<k>) generated by a fitting function F<*(k+1)> with the order of N in the section, and taking E<k> as a fitting object of a VF method at the kth section; when k is equal to 1, stopping the calculation, and outputting a final fitting result when the F<*(1)> with the order of N is taken as the frequency to respond F (omega); obtaining a frequency domain equation of a transient voltage traveling wave U of the transmission line side; realizing frequent-time domain conversion by pull inverse transformation, and acquiring the time domain expression u(t). After the method is adopted, scientific calculation basis is provided for analysis, rapid calculation, protection evaluation and the like of DC transmission line faults of a high-voltage / extra-high voltage DC system; the method is very high in practicality during engineering practice.

Description

technical field [0001] The invention relates to the research field of power system fault calculation methods, in particular to a fast traveling wave calculation method for fault voltage of a high-voltage / ultra-high voltage DC line. Background technique [0002] Traveling wave protection is the main protection of DC line. Accurate calculation of electromagnetic transient electrical quantities related to DC line fault traveling wave protection is the basis for correct analysis of the action behavior of traveling wave protection. Due to the complexity of the topology of the DC system itself and the faults of the DC line, the existing fault analysis is often completed by electromagnetic transient simulation software. Although the detailed electromagnetic transient simulation method can simulate the fault traveling wave process of the high-voltage DC line fault in detail, when the traditional numerical simulation is applied to the research of traveling wave protection of the DC s...

AI Technical Summary

Problems solved by technology

Although the detailed electromagnetic transient simulation method can simulate the fault traveling wave process of the high-voltage DC line fault in detail, when the traditional numerical simulation is applied to the research of traveling wave protection of the DC system, there are only data at discrete time nodes, and the calculation efficiency is high when the sampling frequency is high. It is difficult to apply to occasions that have high requirements for computational efficiency, so it is necessary to propose a new method to improve computational efficiency while ensuring computational accuracy

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