Electromagnetic compatibility of voltage source inverters for uninterruptible power supply system depending on the pulse-width modulation scheme

The pulse-width modulation (PWM) scheme is an algorithm for inverter switch control. A two-leg bridge and three-level PWM are typical solutions in voltage source inverters in uninterruptible power supply systems. The three PWM schemes that are used in inverters are compared herein. Each scheme has different features, including the level of noise generated and interference in the different frequency ranges. The aim of this study is to analyse the characteristics and electromagnetic interference that is generated by an inverter using different PWM schemes.