A new interleaved three-level Boost converter and neutral-point potential balancing

Due to a voltage imbalance of the divided capacitors in the output side of three-level Boost photovoltaic grid-connected inverter, a new topology of interleaved three-level Boost converters is presented. The proposed topology can balance the voltage of the divided capacitors through adjusting the duty cycle of the power switches. The operational principle is detailed and the work modes are analyzed. The neutral point drift problem of the inverter has been solved within the first level three-level Boost converter. The prototype has been verified both by a PSPICE simulation and a new topology inverter platform. Simulation and experimental results show that the current ripple of the converter equals to 1/8 of the traditional Boost converter current ripple, and the converter can well solve the neutral point drift problem of the inverter with voltage divided capacitors to obtain good dynamic and steady-state performance.