ABSTRACT:
This
paper presents a Finite Control Set Model Predictive Control (FCS-MPC) for grid-tied
Packed U Cells (PUC) Multilevel Inverter (MLI). The system under study consists
of a single-phase 3-cells PUC inverter connected to the grid through filtering
inductor. The proposed competitive topology allows the generation of 7-level
output voltage with reduction of passive and active components compared to the
conventional multilevel inverters. The aim of the proposed FCS-MPC technique is
to achieve, under various operating conditions, grid-tie current injection with
unity power factor and low Total Harmonic Distortion (THD) while balancing the
capacitor voltage. Parameters sensitivity analysis was also conducted. The
study is conducted on a low power case study single-phase 3-cells PUC inverter
and with possible extension to higher number of cells. Theoretical analysis,
simulation, and experimental results are presented and compared.
KEYWORDS:
1. Grid Connection
2. Model Predictive Control
3. Packed U Cells Inverter
4. PUC
SOFTWARE: MATLAB/SIMULINK
CONCLUSION:
This
paper presented the design, simulations, and experimental validation of a
FCS-MPC technique that properly deals with the complex nature of the PUC.
Digital simulation for a grid-connected 7-level single-phase PUC inverter was
carried out. The simulation results showed that the proposed MPC is capable of
simultaneously controlling multi variables of the PUC inverter. The tuning of
the weighting factor was conducted successfully based on minimizing the grid
current THD as well as the capacitor voltage error. Using the properly selected
weighting factor, the MPC has shown an efficient and stable tracking of the
reference current at steady state and fast transient response. It is also
capable of maintaining the capacitor voltage at its pre-selected and desired
level. Parameters sensitivity analysis was carried out and showed that the
parameters variation does not have a significant effect on the controller
performance. The obtained experimental results confirmed the simulation results
and demonstrated that the proposed MPC is effective in controlling the grid
current with high steady-state and dynamic tracking performances while keeping
balanced capacitor voltage.
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