Systems and methods for bi-directional onboard battery charging functions in separately excited motor drives

A motor vehicle comprising:

• a vehicle body;
• a plurality of road wheels attached to the vehicle body;
• and
• a rechargeable energy storage system attached to the vehicle body and including a battery assembly containing multiple rechargeable battery cells;
• a multilevel power factor correction (PFC) device electrically connected to the battery assembly and configured to electrically connect to an off-board electric power source and, once connected, interpose between the battery assembly and the electric power source;
• a traction inverter module (TIM) device electrically connected to the battery assembly or the PFC device, the TIM device containing multiple pairs of TIM switches;
• a multilevel rotor power transfer circuit (PTC) device electrically connected to the battery assembly, the TIM device, and the PFC device, the rotor PTC device containing multiple pairs of PTC switches;
• and
• a separately excited motor (SEM) unit attached to the vehicle body and operable to drive one or more of the road wheels to thereby propel the motor vehicle, the SEM unit including a rotor assembly and a stator assembly, the rotor assembly including a rotor core bearing an electromagnetic rotor winding, and the stator assembly including a stator core bearing multiple electromagnetic stator windings that electromagnetically pair with the rotor winding, wherein each of the stator windings is electrically connected to a respective one of the pairs of TIM switches, and the rotor winding is electrically connected to the PTC switches.

A method of manufacturing a motor drive system, the method comprising:

• receiving a battery unit containing a rechargeable battery cell;
• connecting a multilevel power factor correction (PFC) device to the battery unit, the PFC device being configured to electrically connect to the electric power source and interpose between the battery unit and the power source, the PFC device containing multiple PFC switches;
• connecting a traction inverter module (TIM) device to the battery unit and the PFC device, the TIM device containing multiple pairs of TIM switches;
• connecting a multilevel power transfer circuit (PTC) device to the battery unit and the PFC device, the PTC device containing multiple PTC switches;
• receiving a separately excited motor (SEM) unit with a rotor assembly and a stator assembly, the rotor assembly including a rotor core bearing an electrically conductive rotor winding, and the stator assembly including a stator core bearing multiple electrically conductive stator windings that electromagnetically pair with the rotor winding;
• connecting each of the stator windings to a respective one of the pairs of TIM switches;
• and
• connecting the rotor winding to the PTC switches.