A Modular Multi-Terminals PV Interfacing System

In this project, an interface system of PV arrays at medium-voltage level using power electronics converters is proposed. The propose system consists of many low-power low-voltage PV modules. Each module has a low cost dc-dc converter integrated with a maximum power point tracking (MPPT) controller to extract the maximum power and boost the output dc voltage. The PV modules are connected to H-bridge coupled with a high frequency multi- secondary winding to convert the dc output voltage from the PV to high-frequency ac. Each secondary winding is connected to a diode rectifier bridge followed by a small capacitor to filter the dc output voltage. All the secondary windings are connected in series to boost the dc-output voltage from lowvoltage level at the PV module terminal to medium-voltage level, An inductor is added in the output side to smooth the output current and to make each module appears as a current source. Finally, all the PV modules are connected in parallel through the aforementioned described converters and the produced power is collected through a capacitor bank. One of the main advantageous of this system is dedicating converter to each PV module to allow efficient operation under partial shading conditions and to enhance the reliability of the system. A high power dc-ac converter such as Neutral Point Clamped (NPC) or multilevel converter is utilized to deliver the harvested power to the ac grid by regulating the dc-link voltage at proper level.
Simulation and experimentation results are provided to demonstrate the validity of the proposed system