Method and device for judging static voltage stability of power system

Abstract

The embodiment of the invention provides a method and a device for judging the static voltage stability of a power system. The method comprises the following steps of acquiring the distribution probability of each node voltage between different voltage intervals in a power system; according to the weight between different voltage intervals, weighting the distribution probability to obtain a weighted voltage entropy, and further judging the stability of the static voltage of the power system. According to the embodiment of the invention, the condition that voltage levels between every two intervals are different is considered, and the distribution probability is weighted according to the weight between different voltage intervals to obtain the weighted voltage entropy. Furthermore, the stability of the static voltage of the power system is judged based on the weighted voltage entropy. Therefore, the specific parameters of the power system do not need to be known. The method and the device are small in calculation amount, simple and efficient. Meanwhile, the calculation amount cannot be increased along with the scale increased condition of the power system.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of power systems, and more specifically, to a method and device for judging static voltage stability of a power system. Background technique [0002] In recent years, voltage collapse accidents have occurred many times in power systems at home and abroad, long-term large-scale power outages and huge economic losses have caused the research on voltage stability problems to attract widespread attention worldwide. In order to prevent voltage instability and voltage collapse accidents, it is necessary to formulate an index to determine the degree of voltage stability, so that dispatchers can make correct judgments and take corresponding countermeasures. The voltage stability of the power system refers to the ability of the power system to maintain voltage stability on all buses after a disturbance under a given initial operating condition. The main factor causing voltage instability is tha...

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Problems solved by technology

These methods have their own defects: the sensitivity method judges the stability of the system by calculating the sensitivity of the system variables to the disturbance under a certain disturbance. The physical concept is clear and the solution is convenient. It is worth noting that the analysis of simple systems is also ideal, but with the increase of power system scale, it is no longer the mainstream method of static voltage stability analysis; load margin is the most basic and widely accepted voltage collapse index, However, the load margin requires a lot of power flow calculations, and the load margin requires assuming the way of load growth. The margin obtained by different load growth modes is not the same, and sometimes this information is not easy to obtain; the minimum singular value method uses the power flow The minimum singular value of the comparable matrix is ​​used as the voltage stability index, and its disadvantage is that the calculation amount increases with the increase of the system scale, and the prediction degree of the collapse point is poor

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