Examinando por Autor "Zheng, Changming"

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    Finite-Set Quasi-Sliding Mode Predictive Control of LC-Filtered Voltage Source Inverters
    (Institute of Electrical and Electronics Engineers Inc., 2022-12-01) Zheng, Changming; Gong, Zheng; Wu, Xiaojie; Dragicevic, Tomislav; Rodriguez, Jose; Blaabjerg, Frede
    Three-phase voltage source inverters (VSIs) with output LC filter are preferred topologies to provide voltage and frequency support for islanded ac microgrids. This article proposes a finite-set quasi-sliding model predictive control (FS-QSMPC) scheme for LC-filtered VSIs to improve the output-voltage quality. By explicitly including a predictive sliding-mode function into the cost function, reduced steady-state ripple and enhanced robustness are achieved compared to typical FS-MPC. Besides, theoretical analysis of stability and robustness for FS-QSMPC is given. Analytical tuning of the weighting factor is also derived to decrease the tuning effort. Comparative simulations and experiments verify the presented approach. © 1982-2012 IEEE.
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    Ítem
    Model Predictive Control of LC-Filtered Voltage Source Inverters with Optimal Switching Sequence
    (Institute of Electrical and Electronics Engineers Inc., 2021-03) Zheng, Changming; Dragicevic, Tomislav; Zhang, Zhenbin; Rodriguez, Jose; Blaabjerg, Frede
    Voltage source inverters with output LC filter enable a sinusoidal output voltage with low harmonics, suitable for islanded ac microgrid or uninterruptible power supply applications. Conventional finite-set model predictive voltage control (MPVC) applies only a single switching vector per control period, leading to a variable switching frequency and significant output ripple. This article resolves these issues by proposing an improved MPVC with optimal switching sequence (OSS-MPVC). First, an improved vector switching sequence is defined, aiming to reduce the output-voltage ripple with a constant switching frequency. Then, to tackle the difficulty in extending the OSS to high-order systems due to the coupling effect of the output filter, a generalized 'one-step estimation' solution is proposed, which directly associates the control-variable gradients with the vector switching sequence. To further enhance the output-voltage tracking accuracy, intersample dynamics are taken into account in the cost function. The control delay and dead-time compensation are also considered. Simulations and experimental results verify the feasibility of the proposed method.