| Topology of multilevel converter and technique of multi-level PWM is studied in this paper. And the mathematic model of cascaded multilevel circuit is presented based on its principle analysis. Due to the large number of voltage space vectors and redundant switching states, there is a problem of computational complexity in multilevel converter, and so the utilization of multi-level inverters with the SVPWM method can not be realized. To resolve the problem, a novel SVPWM technique is proposed , and it is further analyzed in detail in this paper. In order to validate the technique, the simulation and a three-cell cascaded inverters experiment system is set up. DSP and CPLD is made as the key controller of the experiment system. The capabilities of the novel technique is verified by simulation and experimentation. |
