Estimation method for dynamic frequency response function of voltage transformer and realizing device thereof

Abstract

The invention discloses an estimation method for a dynamic frequency response function of a voltage transformer and a realizing device thereof. The estimation method comprises the steps of using a triangular-rectangular mutual-convolution window to carry out time-domain weighting on discrete stimulation and response; carrying out discrete fourier transformation on the weighted stimulation and response; and correcting a peak spectral frequency of the stimulation and response through a discrete peak spectral frequency weighted average algorithm to acquire an estimated result of the frequency response function of the voltage transformer as a ratio of the corrected response frequency spectrum to the stimulation peak spectral frequency. According to the estimation method for the dynamic frequency response function of the voltage transformer and the realizing device thereof, mutual interference of spectrum leakage and harmonic wave in the estimation on the frequency response function of the voltage transformer can be restrained, the estimation stability for the dynamic frequency response function of the voltage transformer is improved, and the real-time accurate estimation on the dynamic frequency response function of the voltage transformer is achieved.

Description

technical field [0001] The invention relates to the field of dynamic system testing, in particular to a method for estimating a dynamic frequency response function of a voltage transformer and a device for realizing it. Background technique [0002] Potential transformers realize the conversion and transmission of grid voltage signals, and are widely used in measuring instruments, meters, and relay protection or control devices. They are the "bridge" between the primary side and the secondary side of the power system. The dynamic performance of the voltage transformer directly determines the overall operation level of the electric energy metering device and the relay protection device. In order to improve the working ability and stability of voltage transformers in dynamic environments, the research on the estimation method of dynamic frequency response function of voltage transformers is a key problem that needs to be solved urgently. [0003] The frequency response functi...

AI Technical Summary

Problems solved by technology

Since in the actual test, the sampling frequency and the fundamental frequency of the grid voltage cannot maintain a strict integer multiple relationship, when the Fourier transform is performed on the input and output signals of the voltage transformer, there is often serious spectrum leakage, which affects the estimation of the frequency response function the accuracy of

In addition, in the power system, due to the existence of a large number of nonlinear loads, the grid voltage signal often contains abundant harmonics, and the mutual leakage interference between harmonics also reduces the accuracy of frequency response function estimation

[0004] At present, in order to realize the accurate estimation of the frequency response function of the voltage transformer in a dynamic environment, technologies such as sine sweep test, low frequency method test, virtual instrument, and self-spectrum calculation have been introduced into the frequency response function estimation, but they still lack high accuracy and resistance. A solution with strong spectrum leakage capability

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