Patent ID: 11878604
Assignee: VOLVO CAR CORPORATION
Field: Transport (Mechanical engineering)
Classification: CPC B  H  Y | IPC B  H

Claim 10:
11. A method for controlling a propulsion system for an electric vehicle having a high voltage battery unit having a first high voltage battery connected in series with a second high voltage battery such that a nominal operating voltage of the high voltage battery unit is the sum of a voltage of the first high voltage battery and a voltage of the second high voltage battery and a first power inverter connected to a first set of three phases of a dual winding three-phase electric machine and a second power inverter connected to a second set of three phases of the dual winding three-phase electric machine, wherein the first three-phase system is formed by the first power inverter and the first set of three phases of the dual winding three-phase electric machine and the second three-phase system is formed by the second power inverter and the second set of three phases of the dual winding three-phase electric machine; the method comprising:
detecting, by a propulsion system control unit, a fault in the first or the second three-phase system; and
operating the first and second three-phase systems in a safe-state mode comprising, if a back electromotive force, back-EMF, of the faulty three-phase system is higher than the operating voltage of the high voltage battery unit, operating the inverter of the faulty three-phase system in an active short-circuit mode, where transistors of the inverter are kept in a closed state, switching of the transistors is stopped and current and voltage is circulating between the inverter and the electric machine of the non-faulty three-phase system in a closed short-circuited loop.