Judging method for first two swaying stability of transient state power angle of wind power integration system

Abstract

The invention relates to a judging method for first two swaying stability of a transient state power angle of a wind power integration system. The judging method comprises steps of structuring an equivalent one machine infinity bus system model applicable to quantitative and qualitative analysis of the transient state power angle stability of a wind-power-containing multi-machine system; calculating the actual grid data by using the OMIB (one machine infinity bus) model; judging a second swaying stability according to sufficient and necessary conditions of the second swaying unstability of the transient sate power angle of the wind power integration system; confirming a relationship between the second swaying stability and the first swaying stability of the power angle in the wind power integration system and judging the stability of first two swaying of the transient state power angle. The judging method expands the transient state power angle stability analysis method which only concerns the unstability of the first swaying after the integration of wind power at present, and provides a theoretical guidance for the transient state stable control of the large scale wind power centralized grid-connected electricity system.

Description

technical field [0001] The invention relates to the technical field of wind power grid connection, in particular to a method for judging the stability of the first two pendulums of the transient power angle of a wind power grid connection system. Background technique [0002] With the commissioning of many large-scale wind power bases in my country, the penetration rate of wind power in the power system, especially in local power systems, is continuously increasing. Doubly-fed induction generator (DFIG) is commonly used in large wind power bases. DFIG has a control capability different from that of synchronous units under fault conditions. As the penetration rate of DFIG-type wind turbines continues to increase, the impact of its transient control behavior on the transient power angle stability of power systems has become an important research topic. When studying the transient power angle stability of a power system, not only the first pendulum stability but also the secon...

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Problems solved by technology

[0004] In the prior art, although some studies have been done on the stability of the second pendulum of transient power angle in conventional power systems without wind turbines, due to the transient characteristics of wind turbines different from synchronous turbines, large-scale wind power connected to the grid not only The stability of the first pendulum of the transient power angle has an impact, and the influence on the stability of the second pendulum is more worthy of attention. However, so far, little attention has been paid to the stability of the second pendulum stability of the transient power angle of the power system containing large-scale wind power.

If we only care about the stability of the first pendulum but not the stability of the second pendulum, there will be the following two problems: 1. The essence of the transient stability of the large-scale wind power centralized grid-connected system cannot be recognized clearly, that is, the instability of the first pendulum and the second pendulum are hidden. The phenomenon of pendulum instability alternately occurs, and people cannot distinguish whether the transient instability belongs to the first pendulum or the second pendulum instability, so effective stability control methods cannot be adopted

2. The instability of the second pendulum is more threatening to the overall stability of the transient power angle than the instability of the first pendulum

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