The analysis and simulation to the parallel connected NPC-PWM inverters

This paper introduces the circuit and PWM control strategies of the neutral-point-clamped (NPC) inverter and cascade-inverters with separate DC source (CISDS), analyzes and compares their advantages and disadvantages. A new type of parallel connected NPC inverter (PCNPCI) is proposed here. Based on inherited all merits of the three-level structures, only added very few components, it can produce many more voltage levels, which means much small du/dt. And also the output current is doubled. The control strategy for it, which is presented along with the simulation in MATLAB soft package, is simple, efficient.