A Novel SVPWM for Open Winding Permanent Magnet Synchronous Machine With Extended Operation Range

In this article, a novel space vector pulsewidth modulation (SVPWM) with the zero sequence current (ZSC) control strategy is proposed to extend the operation range for an open winding (OW) permanent magnet synchronous machine (PMSM). The proposed SVPWM can achieve the ZSC control and extend the operation range by considering voltages in the zero sequence axis and voltage vectors in the
$\alpha \beta $
-plane, both of which are mapped by switching combinations in an OW drive. The effect of switching combinations with non-null zero sequence voltage (ZSV) on the modulation region of a common-dc bus OW-PMSM is investigated for the first time. The proposed SVPWM has optimal selection of switching combinations on the large hexagon rather than on the small hexagon in the conventional SVPWM for ZSC control and still maintains the controllability of ZSC in the overmodulation region. Compared with the conventional SVPWM strategy, the operation range of OW-PMSM can be extended over 10% with the proposed SVPWM strategy. The performance of both the conventional and proposed SVPWMs is compared experimentally.