Switching Losses And Harmonic Investigations In Multilevel Inverters
Use of conventional two-level pulse width modulation (PWM) inverters provide less distorted current and
voltage but at the cost of higher switching losses due to high switching frequencies. Multilevel inverters are emerging as a
viable alternative for high power, medium voltage applications. This paper compares total harmonic distortion and switching
losses in conventional two-level inverters with multilevel inverters (three-level and five-level) at different switching
frequencies. An optimized switching frequency has been obtained for a lower level of total harmonic distortion and
switching losses. Diode-clamped, three-phase topology is considered for study. A sinusoidal PWM technique is used to
control the switches of the inverter. Simulation study confirms the reduction in harmonic distortion and switching losses as
the number of the levels increases.
Keywords— Harmonics, Multilevel inverters, Pulse width modulation, Switching losses, Total harmonic distortion.