A new simplified and uniform space vector PWM method for N-level inverters

Abstract

For two-level inverters, the conventional space vector PWM (SVPWM) method is not very difficult to implement. However, it becomes more and more complex and even can’t be realized as the level number of the inverter increases. Therefore, carrier based SPWM are much more preferred in many cases. In this paper, a new simplified and uniform SVPWM method for N-level(N ⩾ 2) inverters is presented from a new point of view. The state of each switch device of the inverter can be determined directly and easily without much calculation, unlike the conventional SVPWM algorithm which needs to determine the position of the voltage space vector and the adjacent vectors. The advantage of the new method is that the realization of SVPWM is greatly simplified and the complexity of the new method increases little as the number of inverter level increases. For multi-level inverters, the neutral-point potential problem can also be resolved easily using the new method. Computer simulations on R-L and PMSM load and experiment on a 400Hz power supply show that the new algorithm is effective and easy to implement not only for two-level inverters but also for multi-level inverters.