Efficient modulation technique and NL control of H-bridge boost converters for battery-supplied AC motor drives

Previous works have shown the design effectiveness of novel two-phase H-bridge DC-DC boost conversion in battery-supplied AC motor drives, increasing the exploitation of power components through DC-link voltage adaptation to AC load. In this work the highest performances of real-time voltage control are investigated, as needed to minimize the DC-link capacitor size and to allow for efficient DC voltage tracking of AC load need. New low-capacitance high-rms-current film power capacitors are adopted accordingly. Unusual power conversion performances are derived, as related to the very low-energy storage in both the DC-link capacitor and the peculiar coupling reactor. A new modulation strategy is also defined to exploit peculiar discontinuous current modes, thus minimizing power loss at light load for further improvement of EV city-drive autonomy. A novel nonlinear complete control strategy is proposed to fulfil steady-state and transient performances by simple cheap realization. Outstanding performances have been obtained by the 30 kW prototype converter, partially shown in the experimental report.