A new topology of transistor clamped 5-level H-Bridge multilevel inverter with voltage boosting capacity

Abstract

Multilevel converters are well suited for medium and high power applications because of its characteristic of synthesizing a sinusoidal voltage on several DC levels. They give good quality output resulting with lower harmonic distortion in the output and lower commutation losses. The main disadvantage is their complex circuit configurations, requiring a great number of power devices and passive components, and a complex control circuitry. A new topology of multilevel inverter for 5-level using the Conventional H-Bridge is proposed in this paper. The proposed topology is referred as new TCHB has the feature like boost output voltage capability along with capacitor voltage balancing. The proposed multilevel inverter uses four auxillary switches and transistor clamped H-bridge (TCHB) with an bidirectional switch. The single cell of conventional H-bridge produces three-level output voltage similar to input DC voltage but the single cell of proposed topology produces five-level output with output voltage double the input DC voltage. The proposed new TCHB and old TCHB 5-level inverter are modeled and simulated on matlab/simulink and compared in terms of the output voltage, total harmonic distortion (THD), No. of switching devices used etc. From the results the proposed inverter provides more output voltage with less harmonics in the output voltage.