On-line detection and filtering methods for sub-synchronous oscillation part of power system

Abstract

The invention provides on-line detection and filtering methods for a sub-synchronous oscillation part of a power system. The on-line detection method comprises: a power signal of a power grid is obtained and a power frequency component in the power signal of the power grid is filtered to extract a sub-synchronous oscillation component; and a detection analysis is carried out on sub-synchronous oscillation component by Fourier transform to generate a frequency, an amplitude, and a phase of the sub-synchronous oscillation component. According to the on-line detection and filtering methods provided by the embodiment of the invention, the sub-synchronous oscillation part in the power signal can be detected and filtered rapid and accurately.

Description

Technical field [0001] The invention relates to the field of electric power, in particular to an online detection and filtering method of subsynchronous oscillation components of a power system. Background technique [0002] In the prior art, the monitoring method of the sub-synchronous oscillation is mainly aimed at the sub-synchronous resonance (Sub-Synchronous Resonance, SSR) caused by series compensation. Monitoring can only be carried out on-site in the power plant. The monitoring signals are mainly taken from the generator set. The monitoring methods can be divided into two measurement methods: mechanical measurement and electrical measurement according to the difference of measurement signals. [0003] The subsynchronous oscillation monitoring method based on the measurement of mechanical quantities uses the dynamic process of the rotor movement of the generator set under the excitation of environmental disturbance to identify the subsynchronous oscillation mode. The large ...

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Problems solved by technology

[0004] Although the mechanical quantity measurement method can judge whether a generator shaft system has resonance in real time and on the spot, it cannot provide early warning, nor can it provide effective information for locating the source of the vibration

The monitoring of the speed signal makes the application of this method only limited to the generator set, which cannot adapt to the current situation of large-scale application of power electronic devices, and cannot realize the monitoring in the whole network; mainly only for accurate detection of the oscillation mode, it is impossible to give Accurate oscillation amplitude and phase information, so that it cannot provide a basis for the location of the subsynchronous oscillation source; the calculation is complicated, and online fast monitoring cannot be realized

[0005] The existing subsynchronous oscillation monitoring method based on electrical quantity measurement can theoretically extract the mode of electrical oscillation, and realize the early warning of subsynchronous oscillation for a single unit, but the existing subsynchronous oscillation monitoring method based on electrical quantity measurement, For example, methods such as Prony, wavelet analysis, TLS-ESPRIT, neural network, etc., all have complex calculations, a large amount of calculation, and are sensitive to noise and transient processes, so it is difficult to truly realize online rapid detection and real-time early warning of subsynchronous oscillations

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