On-line monitoring method and system for system damping based on traction load impact response

Abstract

The invention provides a system damping on-line monitoring method based on traction load impact response. The method includes the steps: firstly, obtaining actual oscillation modes of main intervals of a power grid and strong correlation set information of the modes; secondly, selecting a set that is close to a traction load electrical distance and is a strong correlation set of a main interval mode and making the set serve as a monitoring node on the basis of geographical distribution of traction loads in the power grid and zone division of the oscillation modes of the power grid intervals; thirdly, on the basis of monitoring node dynamic measurement, for a set that enables a person to observe obvious oscillation response under the traction load impact, adopting a Prony method to identify on-line the system interval oscillation frequency and damping ratio information; fourthly, for a set that enables a person not to observe obvious oscillation response under the traction load impact, adopting an ARMA method to analyze set active power noise like signals and obtain real-time oscillation frequency and damping information; and fifthly, emitting alarming information in a grading manner by responding to a condition that the system real-time mode damping ratio is lower than a given threshold.

Description

technical field [0001] The invention relates to the field of on-line monitoring and pre-warning and pre-control of low-frequency oscillations in electric power systems, in particular to an on-line monitoring method and system for system damping based on traction load impact response. Background technique [0002] With the continuous expansion of the scale of the interconnected grid, the low-frequency oscillation of the power system has greatly restricted the transmission capacity of the grid, and has become a prominent problem affecting the security and stability of the interconnected grid. System damping is a key factor in determining whether low-frequency oscillations occur or not, and how large the oscillations are. Current power system operators often obtain the dynamic characteristics of the system, especially the oscillation frequency and damping ratio information, by performing modal analysis calculations on future off-line or real-time power flow sections. Because t...

AI Technical Summary

Problems solved by technology

For the on-line monitoring of low-frequency oscillation, at present, it is mainly based on the trajectory of large-scale power oscillation caused by actual faults, using methods such as HHT and Prony to identify the oscillation mode online, which is difficult to meet the early warning and pre-control requirements of the system's low-frequency oscillation

Moreover, more and more forced power oscillations are observed now, and it is difficult to accurately reflect the actual damping information of the system through the analysis results of methods such as Prony

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