Electric energy dissipating system for a vehicle

Patent metadata

Field	Value
Publication number	US-2024083300-A1
Application number	US-202318239537-A
Country	US
Kind code	A1
Filing date	Aug 29, 2023
Priority date	Sep 14, 2022
Publication date	Mar 14, 2024
Grant date	—

Abstract

An electric energy dissipating system for a vehicle. The system includes an electric power system configured to be electrically connected to an electric traction motor of the vehicle and configured to receive and store electric power generated by the electric traction motor during braking, a fluid conduit, an air flow producing unit configured to provide a pressurized air flow through the fluid conduit, an electric machine, and a transmission arrangement. The electric machine is configured to be powered by the electric power system so as to drive the air flow producing unit via the transmission arrangement in order to dissipate energy from the electric machine. The transmission arrangement includes a first shaft and a second shaft. The first shaft is driven by the electric machine and the second shaft drives the air flow producing unit. The second shaft rotates at higher speed than the first shaft.

First claim

What is claimed is:

1 . An electric energy dissipating system for a vehicle, the system comprising:
an electric power system configured to be electrically connected to an electric traction motor of the vehicle and configured to receive and store electric power generated by the electric traction motor during braking, a fluid conduit, an air flow producing unit configured to provide a pressurized air flow through the fluid conduit, an electric machine, a transmission arrangement, wherein the electric machine is configured to be powered by the electric power system so as to drive the air flow producing unit via the transmission arrangement in order to dissipate energy from the electric machine, wherein the transmission arrangement comprises a first shaft and a second shaft, wherein the first shaft is connected to and configured to be driven by the electric machine and the second shaft is connected to and configured to drive the air flow producing unit, wherein the transmission arrangement is configured such that the second shaft rotates at higher speed than the first shaft.

2 . The electric energy dissipating system of claim 1 , wherein said transmission arrangement has a variable transmission ratio.

3 . The electric energy dissipating system of claim 1 , wherein said transmission arrangement comprises a gearbox with gears for transmitting the rotation of the first shaft to a rotation of the second shaft.

4 . The electric energy dissipating system of claim 3 , wherein said gearbox comprises an intermediate shaft, wherein said first shaft is via a first gear connected to said intermediate shaft such that said intermediate shaft rotates at higher speed than said first shaft, wherein said intermediate shaft is via a second gear connected to said second shaft such that said second shaft rotates at higher speed than said intermediate shaft.

5 . The electric energy dissipating system of claim 3 , further comprising an oil pump configured to feed oil to the gears for lubricating and cooling the gears.

6 . The electric energy dissipating system of claim 5 , further comprising an oil circuit in which the oil fed by the oil pump is circulated, wherein the oil circuit comprises a heat exchanger arrangement located downstream of the gears, wherein oil heated by the gears becomes cooled when passing along the heat exchanger arrangement before being recirculated to the gears.

7 . The electric energy dissipating system of claim 1 , wherein the transmission arrangement comprises a continuously variable transmission (CVT) for allowing seamless change of transmission ratios.

8 . The electric energy dissipating system of claim 1 , further comprising a throttle located at an air intake of the air flow producing unit, wherein the throttle is adjustable to control the intake pressure of the air entering the air flow producing unit, and thereby the power of the air flow producing unit.

9 . The electric energy dissipating system of claim 1 , further comprising a control unit configured to control the amount of energy dissipated from the electric machine by controlling the electric power provided to the electric machine and/or by controlling the transmission ratio of the transmission arrangement and/or by controlling a flow-through area of the throttle.

10 . The electric energy dissipating system of claim 9 , wherein the electric power system comprises a battery for storing regenerated electric energy, wherein the control unit is configured to acquire information indicating the state of the battery, such as state of charge, temperature and/or power, wherein the control unit is configured to control the power provided to the electric machine and/or the transmission ratio of the transmission arrangement and/or the flow-through area of the throttle based on the acquired information indicating the state of the battery.

11 . The electric energy dissipating system of claim 9 , wherein the control unit is connected to the electric power system and the electric machine, wherein the control unit is configured to:
receive information indicating a brake request, and based on said received information indicating a brake request, control the electric power system to power the electric machine.

12 . The electric energy dissipating system of claim 11 , wherein the electric power system comprises an inverter which converts a DC input into an AC output, wherein the electric machine is electrically connected to the inverter, wherein the control unit is configured to, based on said information indicating a brake request, activate the inverter to provide power to the electric machine.

13 . The electric energy dissipating system of claim 9 , wherein the control unit is connected to the electric power system and the electric machine, wherein the control unit is configured to:
receive, from the electric power system, information indicating a current energy dissipation request from the electric power system, and based on said received information indicating a current energy dissipation request, control the electric power system to power the electric machine and/or control the transmission ratio of the transmission arrangement and/or control the flow-through area of the throttle.

14 . The electric energy dissipating system of claim 13 , wherein said current energy dissipation request is based on a desired energy level of the electric power system at an upcoming driving position for the vehicle, wherein before the vehicle arrives at the upcoming driving position, the control unit is configured to control the power provided to the electric machine and or control the transmission ratio of the transmission arrangement and/or control the flow-through area of the throttle.

15 . The electric energy dissipating system of claim 9 , wherein said electric traction motor is a first electric traction motor, wherein said electric machine is a second electric traction motor electrically connected to the electric power system, wherein upon braking of the vehicle, the second electric traction motor is configured to drive the air flow producing unit in order to dissipate at least a part of the electric energy that is generated by the first electric traction motor during the braking.

16 . The electric energy dissipating system of claim 15 , wherein both the first electric traction motor and the second electric traction motor are configured to be coupled to a vehicle gearbox to provide traction force to road wheels of the vehicle, wherein the control unit is configured to decouple the second electric traction motor from the vehicle gearbox and control the second electric traction motor to drive the air flow producing unit and thus dissipating at least part of the electric energy that is generated by the first electric traction motor which is still coupled to the vehicle gearbox.

17 . The electric energy dissipating system of claim 1 , wherein the air flow producing unit is an air compressor configured to compress the received air and transmit the compressed air along the fluid conduit.

18 . The electric energy dissipating system of claim 1 , wherein some of the air received by the air flow producing unit is also guided to the electric machine in order to cool the electric machine.

19 . The electric energy dissipating system of claim 1 , wherein the air flow producing unit includes a liquid injector configured to inject liquid into the air flow in order to increase the mass flow of the pressurized air flow.

20 . The electric energy dissipating system of

Assignees

• Volvo Truck Corp

Inventors

• Rahm Fredrik
• Audhav Tove
• Tennevall Peter

Classifications

• B60L58/15 Primary

  Preventing overcharging · CPC title

• B60L1/003 Primary

  to auxiliary motors, e.g. for pumps, compressors · CPC title

• F04B17/03

  driven by electric motors · CPC title

• B60L2200/36

  Vehicles designed to transport cargo, e.g. trucks · CPC title

• B60L2240/421

  Speed · CPC title