Modified Single-Edge Modulation to Decrease Common-Mode Voltage With Considering Deadtime Effects and Switching Losses for Three-Phase VSIs

As the switching frequency of power semiconductor devices increases, it is necessary to suppress the common-mode voltage (CMV) generated by the pulse width modulation action of the voltage source inverters (VSI), which can produce serious ele-ctromagnetic interference (EMI) and hazards such as motor axial current. This article proposes a modified modulation technique based on the single-edge carrier form to decrease the amplitude and frequency of common-mode voltage by selecting different co-mbinations of active voltage vectors in different voltage vector se-ctors. On this basis, the method of optimizing the sequence of vol-tage vector action is adopted to reduce the switching losses of the inverter. And designing a reasonable carrier frequency variation function based on the mathematical derivation considering phase angle of output current and distribution characteristics in the time-domain of switching frequency, which is combined with ab-ove modified modulation strategy to further restrain the switchi-ng losses and differential-mode conducted EMI. Moreover, a dea-dtime effect correction methodology for estimating the phase cur-rent at the moment of switching action is introduced to eliminate the CMV spikes during the deadtime interval. Finally, experime-ntal platform is built to validate the effectiveness and practicality of the modified single-edge modulation (MSEM) technique.