A method, device and system for active damping control of LCL converter based on multi-objective constraint lookup table

Abstract

The present invention provides an active damping control method, device and system for an LCL converter based on a multi-objective constraint lookup table. The measured value of the input grid voltage; determine the reference value of the AC side current of the converter and the filter capacitor of the AC side; compare the measured value of the AC side current of the converter and the voltage of the AC side filter capacitor terminal with the reference value, and obtain the error value state quantity; the error value state quantity is sent into the multi-objective constraint lookup table completed off-line; the multi-objective constraint lookup table selects the voltage space vector that effectively reduces the error value according to the error value state quantity, and according to the voltage space vector The switching state of the converter is adjusted to realize the active damping control of the LCL converter. The invention effectively solves the system output current resonance problem caused by the LCL filter, and realizes high-quality tracking control of the command reference current.

Description

technical field [0001] The invention relates to an active damping control method for an LCL converter system, in particular to an active damping control method for a two-level LCL converter system. Background technique [0002] The grid-connected converter is generally realized by a voltage source inverter (Voltage Source Inverter, VSI). In order to reduce the high switching frequency PWM voltage wave output by the inverter The filter is connected to the grid to form a grid-connected converter system. Compared with traditional single-L filters, LCL filters have been more and more applied to the field of power electronic converters due to their advantages of small size, light weight, and strong attenuation of high-frequency harmonics. However, the resonance problem of LCL itself may affect the stability of the system, so an additional damping control method must be used to suppress the resonance and improve the system stability. [0003] The commonly used damping methods ar...

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Problems solved by technology

However, this kind of control method is affected by the virtual impedance factor and the system robustness is poor. Therefore, in order to give full play to the advantages of the current tracking control based on the look-up table, the present invention proposes an LCL type variant based on a multi-objective constraint look-up table. active damping control method

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