Design and Implementation of a Three Level NPC Inverter for Low Voltage Applications

This paper presents the simulation, the design, and the implementation of a three-level neutral point clamped (NPC) inverter. This inverter is designed for low voltage applications. As the modulation technique, in this paper it is used a simplified version of the space vector pulse width modulation (PWM) strategy. This PWM strategy is based on the average value of the instantaneous maximum and minimum values of the index modulation signals, given in the stationary three-phase reference frame. This simplified PWM technique reduces the computational burden in obtaining the PWM gate signals. A simulation of the NPC inverter with a RL load is carried out in MATLAB Simulink. To support the simulation results, a NPC inverter prototype is design and it is used. The experimental and simulation results show the same behavior during the test. The results show the excellent performance of the inverter prototype and an efficiency of 95.58 %.