A new multilevel inverter model NP without clamping diodes

This paper deals with a novel multilevel inverter neutral point (MNP). This system consists of a series of monodirectional and bidirectional switch. If one or several bidirectional power switches of this inverter burn out or to become ruined by reason an over voltage or depreciation, it stays in the previous level. Indeed, for a three-level NP to occur a defect in bidirectional switch (middle switch), this system operate in two level mode before detecting defect. In this inverter model, we increase the security and the reliability of the power switches. The originality of this inverter is to remove clamping diodes per phase in comparison with the classical multilevel inverter model neutral point clamped (NPC): e.g. for three phase of an inverter with n-level we removed 6.(n-2) diode-clamp. The advantage of delete all clamping diodes is to decrease the conduction losses. The other originality of this work is a simple command strategy with a low switching frequency. At the end we compare simulated and experimental results.