Motor Drive System with Double-Delta-Sourced Stator Winding and Two Modulated NPC Converters

In this paper, method of multi-zone pulsewidth modulation (PWM) has been disseminated for wide-range adjustment of two neutral-clamped converters of double-delta-sourced winding system, which is perspective for application in high power adjustable speed drives with dual-stator-winding motor. In this case, stator winding voltage of system is characterized by symmetries, with the lacking in its spectra of even-order voltage harmonics and sub-harmonics. Also, specific control scheme used for regulation of two inverters assures both elimination of common-mode voltage (CMV), and balanced neutral-point voltage of converters of this installation. Numerical simulations have been executed for systems regulated by three basic versions of synchronous multi-zone pulsewidth modulation.