Electric powertrain with multi-pack battery system

Patent metadata

Field	Value
Publication number	US-11358486-B2
Application number	US-201916571519-A
Country	US
Kind code	B2
Filing date	Sep 16, 2019
Priority date	Sep 16, 2019
Publication date	Jun 14, 2022
Grant date	Jun 14, 2022

Abstract

A multi-pack battery system having at least first and second battery packs each with positive and negative terminals, and each with upper and lower switches respectively connected to the positive and negative terminals. The battery packs have a first voltage level, and are connectable in either series or parallel. A controller controls an ON/OFF state of the switches in response to input signals to select between two series charging modes, three parallel charging modes, and one or more propulsion modes. Some embodiments have a series propulsion mode. An electric powertrain system includes first and second power inverter modules (“PIMs”), an electrical load, front and rear electric machines connected to a respective one of the first and second PIMs, and the battery system. The powertrain system may selectively provide all-wheel, front-wheel, or rear-wheel drive capabilities in each of the various propulsion modes.

First claim

What is claimed is:

1. A multi-pack battery system for a mobile platform having an electrical load, a first electric machine, and a second electric machine, the multi-pack battery system comprising:
first and second battery packs each having multiple switches, the multiple switches including upper switches and lower switches respectively connected to a positive terminal and a negative terminal of the first and second battery packs, wherein the first and second battery packs each have a first voltage level; and
a controller configured to control an ON/OFF state of each of the upper and lower switches of the first and second battery packs in response to input signals to thereby selectively establish:
two series charging modes conducted at a second voltage level that exceeds the first voltage level, and in which the first and second battery packs are connected in series, including a first mode in which the first battery pack powers the electrical load and a second mode in which the second battery pack powers the electrical load;
three parallel charging modes conducted at the first voltage level, including a third mode in which the first battery pack and the second battery pack are connected in parallel and concurrently charged, a fourth mode in which the first battery pack alone is charged, and a fifth mode in the second battery pack alone is charged, wherein either or both of the first or second battery packs powers the electrical load during the fourth mode and the fifth mode; and
three propulsion modes conducted at the first voltage level in which torque from the first and/or second electric machine propels the mobile platform, including a sixth mode in which the first and second battery packs are connected on parallel to concurrently energize one or both of the electric machines, a seventh mode in which the first battery pack alone is used to energize one or both of the electric machines, and an eighth mode in which the second battery pack alone is used to energize one or both of the electric machines.

2. The battery system of claim 1 , wherein the mobile platform is a motor vehicle having a front axle and a rear axle respectively connected to front road wheels and rear road wheels, and wherein the front road wheels and/or the rear road wheels are powered in each of the at least four propulsion modes using the torque from the first electric machine and/or the second electric machine.

3. The battery system of claim 1 , wherein the first voltage level is 300V or more, and the second voltage level is at least twice the first voltage level.

4. The battery system of claim 1 , wherein the upper switches of the first and second battery packs include a pre-charge switch connected in series with a pre-charge resistor.

5. The battery system of claim 1 , wherein the controller is configured to close one or two of the upper and/or lower switches of the first and/or second battery packs to connect the first and second battery packs in series and thereby establish the two series charging modes.

6. The battery system of claim 1 , wherein one or two pairs of the switches of the first and second battery packs are closed to thereby connect the battery system to an offboard charging station during the two series charging modes and the three parallel charging modes.

7. The battery system of claim 1 , wherein the controller is configured to determine a difference between respective states of charge (“SOCs”) and voltages of the first and second battery pack, and to select between the third mode, the fourth mode, or the fifth mode of the charging modes, and the seventh mode and the eighth mode of the propulsion modes, based on the difference to thereby balance the respective SOCs and voltages of the first and second battery packs.

8. The battery system of claim 1 , wherein the controller is configured to select between the sixth mode, the seventh mode, and the eighth mode based on a corresponding electrical fault status of the first battery pack and the second battery pack, with the sixth mode being a default mode when neither the first battery pack nor the second battery pack has an electrical fault.

9. An electric powertrain system for a mobile platform having a front drive axle and a rear drive axle, the electric powertrain system comprising:
a first power inverter module (“PIM”) and a second PIM;
an electrical load;
front and rear rotary electric machines connected to a respective one of the first PIM and the second PIM, and each having a rotor respectively connected to the front drive axle and the rear drive axle;
a first battery pack having positive and negative terminals, and having upper switches and lower switches respectively connected to the positive and negative terminals of the first battery pack;
a second battery pack having positive and negative terminals, and having upper switches and lower switches respectively connected to the positive and negative terminals of the second battery pack; wherein each of the first and second battery packs has a first voltage level; and
a controller configured to control an ON/OFF state of each of the upper and lower switches of the first and second battery packs in response to input signals to thereby selectively establish:
two series charging modes each conducted at a second voltage level that is at least twice the first voltage level, and in which the first and second battery packs are connected in series, including a first mode in which the first battery pack powers the electrical load and a second mode in which the second battery pack powers the electrical load;
three parallel charging modes each conducted at the first voltage level, including a third mode in which the first battery pack and the second battery pack are connected in parallel and concurrently charged, a fourth mode in which the first battery pack alone is charged, and a fifth mode in the second battery pack alone is charged, wherein either or both of the first or second battery packs powers the electrical load during the fourth mode and the fifth mode; and
three propulsion modes conducted at the first voltage level in which torque from one or both of the rotary electric machines propels the mobile platform, including a sixth mode in which the first and second battery packs are connected in parallel and concurrently energize one or both of the rotary electric machines, a seventh mode in which the first battery pack alone is used to energize one or both of the electric machines, and an eighth mode in which the second battery pack alone is used to energize one or both of the electric machines.

10. The electric powertrain system of claim 9 , wherein the first voltage level is 300V or more, and the second voltage level is twice the first voltage level.

11. The electric powertrain system of claim 9 , wherein the controller is configured to close one or two of the upper and/or lower switches of the first and/or second battery packs to connect the first and second battery packs in series, and to thereby establish the two series charging modes.

12. The electric powertrain system of claim 9 , wherein one or two pairs of the switches of the first and second battery packs are closed to thereby connect the battery system to an offboard charging station during the two series charging modes and the three parallel charging modes.

13. The electric powertrain system of claim 9 , wherein the upper and lower switches of the first and second battery packs are solid-state switches or relays.

14. The electric powertrain system of claim 9 , wherein the controller is configured to determine a charging voltage of an offboard charging station, and to select between th

Assignees

• Gm Global Tech Operations Llc

Inventors

• Li Shifang
• Ivan William T
• Conlon Brendan M
• Fan Yue

Classifications

• H02J7/575

  Parallel/serial switching of connection of batteries to charge or load circuit · CPC title

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H02J7/52

  for charge balancing, e.g. equalisation of charge between batteries · CPC title

• B60L53/18

  Cables specially adapted for charging electric vehicles · CPC title

• B60L58/22

  Balancing the charge of battery modules · CPC title