Yasha Pirani

Date of Award

January 2023

Document Type


Degree Name

Master of Science (MS)


Electrical Engineering

First Advisor

Hossein Salehfar


Power Electronics switches incur power losses through conduction and transition states and impose harmonic losses on circuits due to their nonlinear properties. One way to optimize power efficiency is to reduce power loss by minimizing the number of circuit switches. This thesis proposes using a half-bridge inverter instead of the commonly used H-bridge in inverter-based topologies to lower the number of switches. To this end, two separate studies are conducted to evaluate the performance of half-bridge inverters in 2-level and multilevel topologies and compared against their respective H-bridge counterparts. For the first two comparative studies, simulation results for 2-level inverter topology reveal that bipolar PWM half-bridge inverter delivers output current THD and power efficiency of 2.99% and 94.87% respectively compared with 3.40% and 91.04% for bipolar PWM H-bridge inverter. For multilevel topology, simulation results demonstrate that half-bridge MLI reaches 3.83% and 95.95% in output current THD and power efficiency respectively compared to 4.08% and 90.98% for H-bridge MLI. Theses results prove that half-bridge inverter produces higher power efficiency and current quality in response to variable loads; therefore, this thesis paper concludes that half-bridge inverter outperforms H-bridge inverter in both 2-level and Multilevel topologies. A third study is also performed to compare the effect of high frequency (bipolar PWM) versus low frequency (Fundamental) switching on half-bridge inverter when deployed in 2-level and Multilevel topologies. The results show that bipolar PWM half-bridge inverter delivers better current quality at 2.99% THD compared to H-bridge at 3.83% while half-bridge MLI yields greater power efficiency at 95.95% compared to 94.87% for bipolar PWM half-bridge under variable loads. For the third comparative study, this paper concludes that half-bridge inverter’s performance depends on type of modulation and topology employed in the circuit and, therefore, performance is application specific as diverse configurations of half-bridge render distinctive advantages and disadvantages.