Feed-forward control method and device for grid-connected inverter and computer readable storage medium

Abstract

The invention provides a feed-forward control method and device for a grid-connected inverter and a computer readable storage medium. The feed-forward control method comprises the following steps of extracting a harmonic signal within a first preset frequency range from the capacitance voltage of a capacitor in a filter connected with the output end of the grid-connected inverter, determining the frequency corresponding to the maximum value of the harmonic amplitude based on the harmonic amplitude of each frequency of the harmonic signal in the first preset frequency range, acquiring a harmonic voltage component by carrying out band-pass filtering with the frequency as the center frequency on the capacitance voltage, and acquiring a feed-forward voltage control component based on the fundamental voltage component and the harmonic voltage component of the capacitance voltage. According to the feed-forward control method and the feed-forward control device of the grid-connected inverter provided by the embodiment of the invention, the suppression effect of an active damping strategy on resonance can be improved.

Description

technical field [0001] The present invention generally relates to the field of grid-connected inverters, and more specifically, relates to a feedforward control method, device and computer-readable storage medium for grid-connected inverters. Background technique [0002] At present, using grid-side AC voltage to suppress grid-side resonance is a feasible solution. In order to reduce the impact on other frequency harmonics, a band-pass filter is used to extract the harmonics near the resonance frequency in the voltage. [0003] In actual operation, although the grid-side reactance and grid-side filter are fixed, the last inductance of the grid-side filter generally uses the leakage inductance of the box transformer, and its inductance value will change. In addition, considering the different lines of different wind farms, the strength of the power grid is also different. In the same wind farm, even the same type of wind turbines, the connection grid lines are different. It ...

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Problems solved by technology

[0003] In actual operation, although the grid-side reactance and grid-side filter are fixed, the last inductance of the grid-side filter generally uses the leakage inductance of the box transformer, and its inductance value will change

In addition, considering the different lines of different wind farms, the strength of the power grid is also different. In the same wind farm, even the same type of wind turbines, the connection grid lines are different. It affects the impedance of the line, so it will indirectly lead to the deviation of the actual converter's grid-side resonance point from the design value, that is, the resonance point is dynamically changed on the basis of the design value, which will affect the suppression of resonance by the active damping strategy adverse effect

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