Method for determining risk degrees of mutual influence of multi-infeed alternating current-direct current system inversion stations

Abstract

The invention discloses a method for determining the risk degrees of mutual influence of multi-infeed alternating current-direct current system inversion stations. The method comprises the following steps that 1, a model corresponding to a multi-infeed alternating current-direct current system is established; 2, disturbance is exerted on a certain inversion station i in the model, 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 other inversion stations j in the multi-infeed alternating current-direct current system, three-phase multi-infeed interaction factors MIIFij of the inversion station i and inversion stations j are calculated; 4, based on the scores of the three-phase multi-infeed interaction factors, the first risk degree Ra and / or the second risk degree Rb of a certain inversion station k are calculated; 5, the first risk degree Ra and / or the second risk degree Rb are compared with reference values (or standard values) so as to determine the risk degrees of one or more inversion stations in the multi-infeed alternating current-direct current system. 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 systems, in particular to a method for determining the risk degree of mutual influence between inverter stations in a multi-infeed AC / DC system. 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, in the absence o...

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Problems solved by technology

[0004] In the prior art, the single-phase multi-infeed interaction factor SMIIF is used to judge the interaction strength between DC converter stations, and the single-phase multi-infeed interaction factor SMIIF is used to find out the cause of commutation failure. However, because the single-phase multi-infeed interaction factor SMIIF only considers the interaction strength of single-phase voltage between different DC drop points, it cannot meet the needs of practical engineering. In addition, according to the "Power Engineering Electrical Design Manual 》, in the calculation of short-circuit current in power system: the dynamic stability and thermal stability of conductors and electrical appliances, and the breaking current of electrical appliances are generally checked and calculated according to three-phase short-circuit

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