A new Multi Level DC Link inverter topology with variable frequency inverted sine carrier PWM under equal switching transition

摘要

This paper presents with a novel course group of multilevel topology to trim down the number of switches, clamping diodes and dearth of capacitors based on DC link. A new variable inverted sine carrier PWM is used as a switching technique with equal switching transition. A multilevel voltage source inverter can be shaped by connecting a Multi Level DC Link (MLDCL) with a single-phase bridge inverter. The MLDCL provides a dc voltage with the shape of staircase reminiscent of the rectified form of a commanded sinusoidal wave, with or without pulse width modulation to the bridge inverter, which in turn alternates the polarity to generate an ac voltage. Compared with the cascaded H-bridge, diode-clamped, flying-capacitor multilevel inverters, the MLDCL inverters can appreciably trim down the switch count as well as the number of gate drivers as the number of voltage levels increases. A new variable frequency inverted sine carrier pulse width modulation (VFISCPWM) with equal switching transition is used to control this proposed topology. Simulation results are obtained and compare with multi carrier phase disposition pulse width modulation (MCPDPWM) to validate the proposed inverter.