Vector-Space-Decomposition-Based Power Flow Control of Single-Stage-Multiport-Inverter-Fed PMSM Drive for Hybrid Electric Vehicles

The single-stage multiport inverter (SSMPI) is one of the high-efficiency power electronic interfaces for hybrid electric vehicles due to its capability of single-stage power conversion from each source to the motor without employing a dc–dc converter. However, it is cumbersome to design the modulation scheme for the SSMPI since the voltage vectors of the SSMPI are unsymmetrically distributed as the dc-link voltage ratio between the two dc ports varies with the state of the sources, which results in a heavy computation burden in the sector identification and vector synthesis. To this end, this article proposes a vector space decomposition (VSD)-based power flow control scheme to simplify the modulation design for the SSMPI, where the unsymmetrical three-level space vector diagram is decomposed into two separate two-level ones. An intuitive decoupled power flow control for each port without affecting the motor drive control can be easily developed with the proposed VSD strategy. The power distribution capability of the SSMPI with the proposed scheme is also analytically revealed. Experiments are presented to verify the effectiveness and performance of the proposed scheme.