Control of an Open-End Winding Electric Drive Fed by a Dual-Inverter Configuration with Common Mode Connected DC Buses

By connecting the midpoints of the two DC buses, the dual-inverter configuration is allowed to achieve the flexibility of the dual-inverter configuration with two separated DC buses, as well as the EMI suppression merit of that with a common DC bus. This novel dual-inverter configuration, in this paper, is used to construct an OEWIM drive, aiming to explore an ideal electric drive structure for new energy vehicles. One of the voltage source inverters (VSI) is supplied by battery, while the other is just connected with a floating capacitor. The two DC buses share a common reference potential. A control scheme, optimizing the machine operation, as well as adjusting the voltage of the floating capacitor is presented. Zero sequence current (ZSC) closed-loop control is achieved through a zero vector redistribution (ZVR) of SVPWM, and the voltage balance of the neutral point is maintained by proper ZSC control. The performance is validated through some RT-box based hardware-in-loop (HIL) tests of a 3kW OEWIM drive.