Method for analyzing stability of power system by considering change characteristic of load

Abstract

The invention provides a method for analyzing the stability of a power system by considering the change characteristic of a load. System instability can be differentiated to belong to angle instability, voltage instability or induction motor instability by the method when load voltage is greatly reduced after a fault appears. Particular for the voltage instability, because the change characteristic of the load is an important factor which influences the voltage stability after the fault, the method can consider the voltage stability of the system of different load change characteristics. The method can judge the instability essence of the power system under different load change characteristics after the fault appears, can be applied to the stability analysis and the operation control of the power system and is beneficial to system operation and an analyst to analyze the property of the system after the fault, thus the analyst can take an effective safety control measure to improve the stable operation level of the power system.

Description

technical field [0001] The invention relates to a method for power system stability analysis and belongs to the field of power systems. Background technique [0002] Power system stability refers to the ability of the power system to maintain stable operation after being disturbed by accidents. Among them, the research on power angle stability has been relatively mature, and a relatively complete analysis and control system has been formed. However, the research on voltage stability is still in the development stage from the concept to the analysis method, and the corresponding research work is far from being mature. At present, the stability problem of the induction motor has been raised in the academic circles, and the research on the stability problem will continue to be deepened. [0003] At present, there is no unified standard for the criterion of voltage instability. The standard used in engineering in my country is to judge according to the magnitude and duration o...

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Problems solved by technology

In the actual system (especially in the transient process after the system is disturbed), it is difficult to change the load according to the constant power factor. The equivalent impedance of the load node is equal to the Thevenin equivalent impedance of the node network as the critical criterion for voltage stability. There will be a large error

[0005] In the on-line operation analysis and control of the power system, from the existing literature and the actual engineering system, when the system voltage drops sharply after a fault, there is no real-time indicator for judging the nature of the system instability. An effective control measure to maintain system stability has brought confusion, lost the best time to save the system, led to further deterioration of system stability, and even system collapse, resulting in immeasurable social impact and economic losses

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