Modeling and Modulation of NNPC Four-Level Inverter for Solar Photovoltaic Power Plant

Abstract EN

Photovoltaic (PV) power plant is an attractive way of utilizing the solar energy.

For high-power PV power plant, the multilevel inverter is of potential interest.

In contrast to the neutral-point clamped (NPC) or flying capacitor (FC) multilevel inverter, the nested neutral point clamped (NNPC) four-level inverter has better features for solar photovoltaic power plant.

In practical applications, the common mode voltage reduction of the NNPC four-level is one of the important issues.

In order to solve the problem, a new modulation strategy is proposed to minimize the common mode voltage.

Compared with the conventional solution, our proposal can reduce the common mode voltage to 1/18 of the DC bus voltage.

Moreover, it has the capability to balance the capacitor voltages.

Finally, we carried out time-domain simulations to test the performance of the NNPC four-level inverter.