Model predictive control for distributed MPPT algorithm of
cascaded H-bridge multilevel grid-connected PV inverters

Bao Binh Pho – Chung Mai-Van – Minh Tran Trong – Phuong Vu

   This paper concentrates on an algorithm with model predictive control for current and distributed MPPT for cascaded H-bridge multilevel photovoltaic (PV) inverter applications. In conventional method, in each sampling period, a discrete-time model is employed to predict the current future values for all vectors of voltage. The voltage vector will be approved if it minimizes the cost function. Because multilevel inverter has so many available voltage vectors, there is a large quantity of calculations, hence it makes difficult in implementing the normal control method. A varied control strategy that extensively decreases the calculations volume and eliminating common-mode voltage is proposed. To raise the PV modules performance and enlarge the system's power, a distributed maximum power point tracking (MPPT) control scheme for each phase of multilevel inverter is offered, that allows its DC-link voltage to be regulated separately. The recommended approach is double-checked by using a model simulated in MATLAB-Simulink software.

Keywords: model predictive current control, multilevel inverter, photovoltaic, cascaded h-bridge, MPPT, common-mode voltage

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