Method for evaluating influence on voltage stability of AC receiving-end grid from DC accessing

Abstract

The invention provides a method for evaluating influence on voltage stability of an AC receiving-end grid from DC accessing. According to the technical scheme of the invention, in a standard looped network which performs equivalent simplification on a hybrid AC / DC system into 'DC-power supply-load', the voltage characteristics under the actions of DC accessing, load dynamics, power supply support and network transmission are comprehensively inspected, a critical fault clearing time is selected as the evaluation index at a load bus, and the influences on the transient voltage stability from a receiving-end AC system are equivalent to the load bus for comparison evaluation. The method brings convenience for simply and efficiently evaluating the influence on the voltage stability of the AC receiving-end grid from a DC accessing mode.

Description

technical field [0001] The invention relates to the field of electric power technology, in particular to an evaluation method for the influence of direct current access on the voltage stability of an alternating current power grid at a receiving end. Background technique [0002] The converter device in the HVDC transmission system itself needs to consume a large amount of reactive power, which is about 40%-60% of its transmission power. In addition to a large amount of reactive power compensation in the converter station, it also needs Get part. In the AC-DC hybrid system, due to the relatively dense DC landing points, the electrical coupling between the AC and DC systems is tight, and the interaction between the AC and DC systems and the DC systems is complex. Faults in the AC system at the receiving end may cause simultaneous or successive commutation failures of multiple DC circuits, and in severe cases may further lead to DC blocking, causing large power imbalances and...

AI Technical Summary

Problems solved by technology

In fact, the nature and magnitude of the dynamic reactive power of the DC system after the disturbance will change rapidly, which will obviously aggravate the complexity of the voltage stability problem

However, the existing technical solutions do not examine the role and function of the DC system in the voltage stability problem

[0009] (2) Existing technology cannot quantify the degree of participation and scope of influence of the DC system on voltage stability issues

[0010] The existing technical solutions only focus on the commutation bus, which splits the coupling relationship among many factors in the voltage stability problem, and cannot take into account the changes in the reactive power of the DC system and the reactive power demand of the load, the reactive power support of the power supply and the The reactive power transfer capability of the network is effectively linked, so it is impossible to quantify the degree of participation and the scope of influence of the DC system on voltage stability issues

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