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 paper 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. Additionally, 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.