Method for determining risk degree of influence on inversion stations of alternating-current junction stations

Abstract

The invention discloses a method for determining the risk degree of influence on inversion stations of alternating-current junction stations. The method comprises the following steps that 1, a model of a multi-infeed alternating current-direct current system is established, including n inversion stations and m alternating-current junction stations; 2, disturbance is exerted on one of the inversion stations i, so that the voltage Ui of a converter bus i of the inversion station i is reduced by 1%; 3, based on voltage variations delta Uj of the inversion stations j in the multi-infeed alternating current-direct current system, three-phase multi-infeed interaction factors MIIFij are calculated; 4, based on the scores of the three-phase multi-infeed interaction factors, the risk degree R of a certain inversion station k is calculated; 5, the risk degree R is compared with a reference value (or a standard value) Rstandard, and when the R is greater than or equal to the reference value Rstandard, it is determined that the risk degree of the inversion station is higher than those of common inversion stations. The method has the guiding effect on finding of potential risks of direct-current station commutation failure and formulation of corresponding prevention measures and can also provide reference indexes for direct-current station address selection.

Description

technical field [0001] The invention relates to the field of power system analysis, in particular to a method for determining the risk degree of an inverter station in a multi-infeed AC / DC system affected by an AC hub station. Background technique [0002] With the full implementation of the strategy of "West-East Power Transmission, North-South Mutual Supply, and National Networking", my country is gradually building a UHV AC-DC hybrid transmission system that is rare in the world for trans-regional and long-distance transmission of huge power. The sexiness and difficulty are also rare internationally. For the multi-infeed AC-DC hybrid power receiving system, due to the strengthening of the grid structure and the increase of the system capacity, the safety and stability characteristics of the grid have changed to a certain extent, and the stability failure accidents of the angle of attack instability are not easy to occur directly in the multi-DC drop point area. However, i...

AI Technical Summary

Problems solved by technology

For the multi-infeed AC-DC hybrid power receiving system, due to the strengthening of the grid structure and the increase of the system capacity, the safety and stability characteristics of the grid have changed to a certain extent, and the stability failure accidents of the angle of attack instability are not easy to occur directly in the multi-DC drop point area. However, in the absence of sufficient dynamic reactive power support and other measures, the occurrence of disturbances may lead to a vicious drop in voltage, causing DC commutation failure, and ultimately leading to system instability in severe cases

[0003] In a large-scale multi-infeed AC / DC power receiving system, due to the close electrical distance between the DC inverter stations and the mutual coupling of the DC systems, the interaction between DC and DC, and DC and AC is stronger, making the response of the DC system deterioration

The commutation failure of one converter station may cause the commutation failure of other converter stations; under the AC system failure, commutation failures may occur simultaneously or successively in each DC converter station, if the DC systems cannot be restored smoothly , causing widespread power outages

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