Mitigation of oscillations in three phase LCL-filtered grid converters based on proportional resonance and improved model predictive control

Geng, Qi, Sun, Huadong, Zhang, Xing, Zhou, Xiaoxin, Liang, Jun ORCID: https://orcid.org/0000-0001-7511-449X and Geng, Yi 2023. Mitigation of oscillations in three phase LCL-filtered grid converters based on proportional resonance and improved model predictive control. IEEE Transactions on Industry Applications 59 (2) , pp. 2590-2602. 10.1109/TIA.2022.3228972

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Abstract

For three phase LCL -filtered gird converters, this paper designs a robust control strategy to reduce high frequency and subsynchronous or supersynchronous oscillations. Two components, namely the grid side inductor component and the LC filter component, constitute a three phase LCL -filtered grid converter. Model predictive control (MPC) with a disturbance observer is used to control the interconnection voltage of the LC filter. Proportional resonance (PR) control regulates the grid side current. It is possible to combine MPC with PR's advantages. The dynamic performance is enhanced by MPC's intrinsic ability to achieve active damping without extra control and reduce modulation latency. In addition to achieving zero steady state error, PR control greatly simplifies the control process when compared to the overall MPC of the entire grid converter. By analyzing the frequency response of the transfer function and output impedance, it is possible to determine that the proposed control has a sufficient phase margin and that, even when the system and control parameters change, the grid converters' output impedance is always resistive or inductive at the entire frequency, suppressing subsynchronous and high frequency oscillations. To further reduce the oscillations and harmonics, an improved MPC control framework and a feedback compensation mechanism are proposed. The effectiveness and reliability of the proposed control in current tracking, harmonic suppression, and response to grid impedance variations are verified by comparative analysis of simulation results.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Engineering
Publisher:	Institute of Electrical and Electronics Engineers
ISSN:	0093-9994
Date of First Compliant Deposit:	18 January 2023
Last Modified:	06 Nov 2023 16:33
URI:	https://orca.cardiff.ac.uk/id/eprint/155930

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