To improve the efficiency of the photovoltaic (PV) system, the centralized topology using three-level inverters are widely used. In this system, PV modules are separately connected to the split DC-links. This causes a decrease of maximum power point tracking (MPPT) efficiency under the partial shading condition. This paper proposes an independent control of two DC-link voltages for separate MPPT of each PV module in three-level inverters. The proposed method is simply implemented by adding or subtracting the time-offset to the three-phase turn-on times and modifying the reference voltages without complex calculations or any additional hardware. Simulations and experimental results verify the validity and feasibility of the proposed methods.
Applied Power Electronics Conference and Exposition (apec), Annual Ieee Conference, 2014, p. 1718-1724
Main Research Area:
I E E E Applied Power Electronics Conference and Exposition. Conference Proceedings
29th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2014