Resonant frequency identification method and device for grid-connected converter equipment, equipment and medium

Abstract

The invention discloses a resonant frequency identification method and device for grid-connected converter equipment, an electronic device and a computer readable storage medium. The method comprisesthe following steps: acquiring a capacitor voltage signal of an LCL filter; extracting a fluctuation component signal of the capacitor voltage signal; sending the fluctuation component signals to twopreset identification controllers with the same structure and different center frequencies to obtain two output identification variable values; performing PI control based on the difference value of the two identification variable values so as to adjust the center frequency of the two preset identification controllers in real time until a closed-loop steady state is entered; and determining the average value of the center frequencies of the two preset identification controllers in the closed-loop steady state as the resonant frequency of the grid-connected converter equipment. By utilizing thefrequency characteristics of the identification results of the two preset identification controllers with different center frequencies relative to the resonant frequency and combining PI closed-loopcontrol, the resonant frequency of the grid-connected converter equipment can be effectively tracked and identified, and the identification rate, accuracy and real-time performance are effectively improved.

Description

technical field [0001] The present application relates to the field of electrical technology, and in particular to a method, device, electronic equipment, and computer-readable storage medium for identifying a resonance frequency of grid-connected converter equipment. Background technique [0002] Grid-connected converter equipment such as grid-connected inverters and reactive power compensators are generally equipped with LCL filters. However, the LCL filter has an inherent resonance point, which is very easy to cause resonance under harmonic excitation conditions, which may lead to system instability. Therefore, the resonance suppression of the LCL filter can be further carried out by identifying the resonance frequency. [0003] In related technologies, when methods such as Fourier analysis are used to identify the resonant frequency, because the Fourier transform needs enough data to ensure the frequency accuracy, it not only takes a long time, but also cannot adapt to ...

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Problems solved by technology

[0003] In related technologies, when methods such as Fourier analysis are used to identify the resonant frequency, because the Fourier transform needs enough data to ensure the frequency accuracy, it not only takes a long time, but also cannot adapt to the frequent changes of the resonant frequency in real time. situation, and it has higher requirements on the computing and storage capabilities of the chip

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