Adaptive real-time detection method for subsynchronous oscillation mode of power grid

Abstract

The invention relates to a real-time dynamic identification and measurement technology for a power system subsynchronous oscillation (SSO) mode by utilizing information of a power grid, and discloses an infinite-impulse-response(IIR)-filter-set-based oscillation mode adaptive real-time detection method. In the method, the current of interconnecting ties is measured in real time, a conductive component in the current is subjected to point elimination through an IIR filter group, and a current signal is limited in a subsynchronous frequency range. After that the SSO happens is detected, main modal components are identified through Fourier transform (FFT) based on different observation windows, the IIR filter group in which IIR filters are mutually band eliminators is dynamically constructed on the basis of the main modal components, the main modal components are separated out, and the whole process is subjected to wave recording. By the method, the SSO modal components of the power grid canbe identified dynamically in real time, the calculation is simple, and the method is easy to implement.

Description

technical field [0001] The invention relates to a mode self-adaptive real-time detection method for subsynchronous oscillation of a power grid side in a power system, and belongs to the field of power systems. Background technique [0002] The network architecture of my country's power system makes subsynchronous oscillation (SSO) exist for a long time, and SSO has always been a research hotspot in power system. [0003] my country's power system can be divided into two parts: the power plant side and the grid side. Since the mechanical natural frequency of the shafting of the turbogenerator is usually within the range of the subsynchronous oscillation frequency, when SSO occurs, the natural parameter model of the power system and the turbogenerator may have the possibility of resonance. Once SSO occurs in the power system, it may cause serious mechanical energy and electrical energy resonance in the shafting of the turbogenerator at the power plant, which will have a destr...

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Problems solved by technology

However, it is very difficult to monitor SSO on the grid side: first, the modal frequency on the grid side changes dynamically, and cannot be monitored for a specific modal frequency, but can only be monitored dynamically; The modal component is extracted from the current. The modal component is not a fault quantity, and its proportion is relatively small. At the same time, it is affected by the power frequency signal, and it is difficult to achieve accurate measurement.

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