High efficiency grid-connected multi string PV PCS using H-bridge multi-level topology

In this paper, a novel topology is proposed that can significantly increase the efficiency of photovoltaic (PV) system. The multi level topology consists of several H-bridge cells connected in series, each one connected to a string of PV modules. The proposed topology offers advantages such as the operation at lower switching frequency or lower current ripple compared to conventional two level topologies. The control algorithm permits the independent control of each dc link voltage, enabling, in this way, the tracking of the maximum power point for each string of PV modules. The proposed topology is implemented for 240kW power conditioning system. The experimental results show that the proposed topology has good performance.