Electrical propulsion system architecture

1. A method of controlling fast charging of a first battery pack and a second battery pack within a high voltage electrical propulsion system for an electric vehicle, comprising:

identifying an operating condition of the electrical propulsion system, wherein the operating condition is one of a first charging mode, a second charging mode and a propulsion mode, wherein, when in the first and second charging mode, the first and second battery packs of the electrical propulsion system are being charged and, when in the propulsion mode, power from the first and second battery packs is routed to electrical power components of the electrical propulsion system;

when the electrical propulsion system is in the first charging mode:

charging the first and second battery packs in the first charging mode by actuating a first plurality of switches to a closed state and actuating a second plurality of switches to an open state to initiate the first charging mode of the first and second battery packs;

terminating the first charging mode by actuating all of the first and second plurality of switches to the open state:

when there is a request to terminate the first charging mode; and

when there is no request to terminate the first charging mode and the charging of the first and second battery packs in the first charging mode is complete; and

when the electrical propulsion system is in propulsion mode, actuating the first plurality of switches to an open state and actuating the second plurality of switches to a closed state to connect the at least one battery pack to power components of the electrical propulsion system.

2. The method of claim 1 , further including:

when the high voltage electrical propulsion system is in the second charging mode:

charging the first and second battery packs in the second charging mode;

terminating the second charging mode when there is a request to terminate the second charging mode; and

terminating the second charging mode when there is no request to terminate the second charging mode and the charging of the first and second battery packs in the second charging mode is complete.

3. The method of claim 2 , wherein charging the first and second battery packs in the second charging mode includes actuating a third plurality of switches to a closed state and actuating a fourth plurality of switches to an open state to initiate the second charging mode of the first and second battery packs; and

terminating the second charging mode includes actuating all of the third and fourth plurality of switches to the open state to terminate the second charging mode.

4. The method of claim 3 , further including, when the electrical system is in propulsion mode:

monitoring a state of charge of each of the first and second battery packs;

providing power to power components within the electric vehicle from the first battery pack when the state of charge of the first battery pack is greater than the state of charge of the second battery pack; and

providing power to power components within the electric vehicle from the second battery pack when the state of charge of the second battery pack is greater than the state of charge of the first battery pack.

5. The method of claim 4 , further including:

providing power to power components within the electric vehicle from only the first battery pack when:

both of the first and second battery packs are healthy;

power demand of the electric vehicle does not exceed a pre-determined threshold value;

a delta between the state of charge of the first battery pack and the second battery pack exceeds a pre-determined threshold; and

the state of charge of the first battery pack is greater than the state of charge of the second battery pack; and

providing power to power components within the electric vehicle from only the second battery pack when:

both of the first and second battery packs are healthy;

power demand of the electric vehicle does not exceed a pre-determined threshold value;

the delta between the state of charge of the first battery pack and the second battery pack exceeds a pre-determined threshold; and

the state of charge of the second battery pack is greater than the state of charge of the first battery pack.

6. The method of claim 5 , wherein the pre-determined threshold for the delta between the state of charge of the first battery pack and the second battery pack is between 0% and 10%.

7. The method of claim 6 , further including:

obtaining temperature, voltage and current information for cells within the first and second battery packs from sensors within the first and second battery packs;

calculating voltage and current within each of the first and second battery packs; and

estimating the state of charge of each of the first and second battery packs.

8. The method of claim 7 , wherein providing power to power components within the electric vehicle from only the first battery pack further includes actuating a fifth plurality of switches to an open state and actuating a sixth plurality of switches to a closed state to provide power to power components within the electric vehicle from the first battery pack and to disconnect power components within the electric vehicle from the second battery pack; and

providing power to power components within the electric vehicle from only the second battery pack further includes actuating a seventh plurality of switches to an open state and actuating an eighth plurality of switches to a closed state to provide power to power components within the electric vehicle from the second battery pack and to disconnect power components within the electric vehicle from the first battery pack.

9. The method of claim 8 , further including, when the power demand of the electric vehicle exceeds the pre-determined threshold value, actuating the first plurality of switches to an open position and actuating the second plurality of switches to a closed state to provide power to power components within the electric vehicle from both the first battery pack and the second battery pack.

10. The method of claim 9 , further including, when the power demand of the electric vehicle does not exceed the pre-determined threshold value and the delta between the state of charge of the first battery pack and the second battery pack does not exceed the pre-determined threshold, actuating the first plurality of switches to an open position and actuating the second plurality of switches to a closed state to provide power to power components within the electric vehicle from both the first battery pack and the second battery pack.

11. The method of claim 10 , further including, when the high voltage electrical propulsion system is in propulsion mode and one of the first and second battery packs is not healthy:

setting a diagnostic code;

providing power to power components within the electric vehicle from the first battery pack and disconnecting power components within the electric vehicle from the second battery pack when the first battery pack is healthy; and

providing power to power components within the electric vehicle from the second battery pack and disconnecting power components within the electric vehicle from the first battery pack when the first battery pack is not healthy.

12. A high voltage electrical propulsion system architecture for an automotive vehicle comprising:

a direct current fast charging unit;

a plurality of power components;

at least one battery pack;

at least one switch adapted to selectively connect the at least one battery pack to one of the direct current fast charging unit and the power components within the automotive vehicle, wherein, at least one of the at least one switch is a solid-state switch in functional engagement with a current sensor, the solid-state switch and the current sensor adapted to precisely limit a fault current of the solid-state switch, the solid-state switch further adapted to allow ramping of a pulse width modulation (PWM) duty cycle of a control signal to limit an inrush of current when the at least one battery pack is initially connected to a load with capacitive input.

13. The high voltage electrical propulsion system architecture of claim 12 , wherein the at least one switch includes:

a first plurality of switches, the first plurality of switches defining a charging circuit when each of the first plurality of switches are closed; and

a second plurality of switches, the second plurality of switches defining a power circuit when each of the second plurality of switches are closed.

14. The high voltage electrical propulsion system architecture of claim 13 , further including at least one hybrid switch comprising a solid-state switch in parallel with a mechanical contact switch.

15. The high voltage electrical propulsion system architecture of claim 14 , wherein at least one of the at least one switch is a single pole double throw mechanical switch.

16. The high voltage electrical propulsion system architecture of claim 14 , further including a dedicated pre-charge circuit.

17. The high voltage electrical propulsion system architecture of claim 12 , wherein the at least one battery pack includes a first battery pack and a second battery pack, the electrical propulsion adapted to operate in one of an 800 volt charging mode, a 400 volt charging mode and a propulsion mode.