A fast algorithm for three-level SVPWM in NPC inverters based on traditional three-level SPWM

A fast algorithm for three-level space vector pulse wide modulation (SVPWM) in neutral point clamped (NPC) inverters based on traditional three-level sinusoidal pulse wide modulation (SPWM) is proposed. The acting time relation of each state in each phase is got by deeply researching the similarities and differences of three-level SPWM and SVPWM. This algorithm can realize all kinds of state sequences easily, it does not need to do trigonometric function, irrational operation and coordinate transformation, it just needs ordinary arithmetic, therefore the calculation is very simple and the result is much more accurate. The fast algorithm can be easily implemented on microprocessor and the executing speed is faster than the conventional three-level SVPWM algorithm.