Determination method and device for critical clearing time

Abstract

The invention discloses a determination method and device for critical clearing time. According to the method, first, a critical clearing time initial value tcr is calculated and determined through a direct method, second, a search range is determined according to the critical clearing time initial value tcr and a time domain simulation system error; and last, a dichotomy method is adopted to search for and determine the critical clearing time CCT within the search range. According to the determination method and device for the critical clearing time, a calculation result of the direct method is used as the initial value, a time domain simulation method is adopted to perform precise search based on the initial value, and therefore the accuracy of a critical clearing time result is guaranteed while calculation speed is increased.

Description

technical field [0001] The present invention relates to the field of power network analysis, and more specifically, relates to a method and device for determining a critical cut-off time. Background technique [0002] In recent years, as the country has vigorously promoted the construction of power grids, the scale of power grids has become larger and larger, and the power grid systems have become more and more complex. The safe and reliable operation of large power grids has become a key research topic for technicians in the field. In the power grid analysis work, the calculation of the transient stability limit is of great significance to the safe operation of the power grid. At present, the main methods for analysis of transient stability parameters are time-domain simulation method and direct method. [0003] The time-domain simulation method uses detailed models and step-by-step integration methods to obtain the precise running trajectory of the system after a fault. ...

AI Technical Summary

Problems solved by technology

Some disadvantages of the time-domain simulation method include: ①When it is used for the transient stability analysis of the whole process of a large system, the calculation workload is large and the computer time is long

②It can only judge whether the system is stable or unstable, and cannot provide a continuously quantified numerical index; ③For the large amount of information obtained in the simulation process, the utilization rate is low

Although the transient energy function method has become mature, there are still many shortcomings and limitations in practical application, mainly as follows: ① The adaptability to the model needs to be further improved; ② The results obtained by the analysis can only provide the system dynamic process The characteristics and some valuable information cannot provide the time response of the system variables; ③ If the system is unstable, the analysis of the transient energy function method cannot indicate how the system is out of step, nor can it indicate whether the part of the system that is decoupled is from damage; ④ cannot reflect the stability of the system with switching operations

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