Dual-Layer SVM-Based Power Flow Control of ANPC-Type Multiport Inverter in Multisource Electric Vehicles

The active-neutral-point-clamped (ANPC) multiport inverter can serve as a high-efficiency interface for multisource electric vehicles by eliminating the need for intermediate dc–dc converters. However, achieving precise power flow control between dc sources, while ensuring satisfactory motor control becomes challenging, particularly under unbalanced dc port voltages. To address this issue, this article proposes a dual-layer space vector modulation (SVM)-based control strategy for ANPC-type multiport inverters to enable simultaneous power flow control between dc sources and motor drive regulation, even under unbalanced dc port conditions. In the proposed scheme, the asymmetrical three-level SVM is decomposed into symmetrical upper and lower layers based on the switching state of the low-frequency cell, simplifying the calculation of dwell time under unbalanced dc-link voltages. And a direct power control scheme is applied in the upper-layer SVM to realize the desired power flow between the dc sources. In addition, the proposed dual-layer SVM ensures that the low-frequency cell operates at the fundamental frequency, even in the presence of dc-link imbalance. The power distribution range of the proposed scheme is also analytically discussed. Experimental results confirm the effectiveness of the proposed dual-layer SVM-based power flow control scheme.