Subharmonics Generated by Space Vector Modulation in Ultrahigh Speed Drives

Comparison of Naturally Sampled PWM techniques in ultrahigh speed drives

“…(Table I). In [3] it was shown supported by simulation and test results that, even thoughV sub is small but being f sub very small high level of subharmonic flux components can be generated in applying SVM.…”

“…The currents generated by the DC voltage components in the phase voltages of USIM are limited only by the small stator resistance therefore the problem caused by them can be serious [3].…”

“…Generally the NS-PWM techniques in the past was implemented by using analog devices [1], nowadays up-to date digital devices are used that make accurate implementation of the NS-SVM possible [3], [2], [4], [5], [6].…”

“…In this paper two most widely applied carrier-based PWM techniques using sinusoidal signal (SPWM) and sinusoidal plus third-harmonic reference signal (THI-PWM) as reference waveform are compared with the widely used Space Vector Modulation (SVM) technique [3], [7], which can be also realized as a carrier-based PWM [8]. The paper compares the three different techniques by assuming natural sampling and low frequency ratios.…”

DC components and subharmonics of carrier-based PWM

“…However if 10 / 1 < = f f m c the dc voltage and subharmonics can produce unfavorable phenomena. In [8] it was shown, supported by simulation and test results, that by applying space vector PWM even a low subharmonic voltage component can result in subharmonic flux with considerable level.…”