A novel switching signals generation method for hybrid multilevel inverters

Use of multilevel inverters is becoming more popular in the recent years. Various topologies and modulation methods have been reported for utility and drive applications in the recent literature. Hybrid multilevel structures are the new multilevel inverter topologies where the cascaded series inverters have different internal DC bus voltages and/or modulated quite differently. This paper introduces a novel switching signals generation (modulation) method for hybrid multilevel inverters. This method is new and based on reference signal tracking. The structure of modeled hybrid multilevel inverter and operating principles of the proposed method are presented. The proposed method is verified by computer simulations using PSCAD/EMTDC. The waveform and THD values are presented and analyzed, which prove the validity of the proposed method.