A Realization Method of Synchronized Phasor Measurement with Filtering Out Decaying DC Component

Abstract

The invention relates to the technical field of synchronous phasor measurement of an electric system, in particular to a synchronous phasor measurement method with filtered-out attenuation direct current components. The synchronous phasor measurement method includes the steps of based on a traditional DFT algorithm, respectively calculating real parts and imaginary parts of three continuous data window fundamental components with a composite trapezoidal rule and a linear interpolation method, then calculating error estimation values of the real parts and the imaginary parts, correcting the original real parts and the original imaginary parts through the obtained error estimation values, and filtering out influences of the attenuation direct current components in the electric system on the synchronous phasor measurement method. The method has the high synchronous phasor measuring accuracy and the high noise resistance under the electric system static condition and the electric system dynamic condition, the influences caused by the attenuation direct current components in the electric system are filtered out, and the measuring accuracy of the synchronous phasor measurement method when the electric system fails is improved.

Description

technical field [0001] The invention relates to the technical field of synchronized phasor measurement in electric power systems, in particular to a synchronized phasor measurement method for filtering attenuated DC components. Background technique [0002] With the development of the global power market and regional power grid projects, the operating environment of the power grid has become increasingly complex, and new security risks have also emerged. It is particularly important to monitor the power grid in real time under the dynamic conditions of the power system. At present, Wide Area Measuring System (WAMS), as a new type of high-efficiency power grid dynamic monitoring system, provides a new technical guarantee for power grid dynamic security monitoring. The data collected by WAMS is synchronous, and at the same time, the processing results of the collected data require that the phasor data have precise time scales, so the synchrophasor measurement technology is the...

AI Technical Summary

Problems solved by technology

The zero-crossing detection method is easily affected by random noise and harmonics at the zero-crossing point of the signal, and the real-time performance is not good. It is easily affected by the dynamic conditions of the system, and the measurement error is not easy to control.

The instantaneous value method requires the waveform of the signal to be a standard power frequency sine wave, which has high requirements on the input waveform, is not universal, and has a large amount of calculation

The Prony method cannot reflect the non-stationarity of the system under dynamic conditions, and the noise has a great influence on its fitting results. When the noise signal-to-noise ratio is less than 40dB, incorrect results will be obtained

The wavelet transform method cannot be well reflected in the synchrophasor measurement of the narrowband signal with the rated frequency as the center frequency, and the speed of the synchrophasor measurement will be affected due to the complexity of the wavelet analysis operation and the addition of a digital signal processor (DSP) burden

The Kalman filter method has a large error in the phase angle measurement of the synchronized phasor, which cannot meet the requirements of the phase angle measurement of the synchronized phasor.

Under the dynamic conditions of the power system, for example, when the signal frequency shifts, the DFT method will produce a large error due to frequency leakage.

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