A method and device for charging an electric energy storage system in a vehicle

Patent metadata

Field	Value
Publication number	US-2017341527-A1
Application number	US-201415535996-A
Country	US
Kind code	A1
Filing date	Dec 15, 2014
Priority date	Dec 15, 2014
Publication date	Nov 30, 2017
Grant date	—

Abstract

A device/method for the control of a charge operation and the State Of Charge (SOC) of an electrical Energy Storage System (ESS), e.g. a battery, that includes a multitude of cells is provided. The ESS is electrically connected to a propulsion system of a vehicle in order to power an Electric Motor. The method includes charging the ESS from an electrical power source, e.g., the grid, when the vehicle is at standstill, stopping the charging when the SOC level of the ESS is above a maintenance limit for the SOC level of the ESS, monitoring the battery and/or performing a service operation of the ESS after the ESS has been charged to a SOC level above the maintenance limit for the SOC level of the ESS, deliberately discharging the ESS to lower the SOC level. The SOC level of the ESS is reduced to a take-off limit for the SOC level of the ESS which is set in order to allow the vehicle to be controlled to use regenerative braking for charging of the ESS under subsequent driving when the vehicle is restarted and takes off.

First claim

1 . A method for the control of a charge operation and the State Of Charge (SOC) of an electrical Energy Storage System (ESS), e.g. a battery, comprising a multitude of cells, said ESS electrically connected to a propulsion system ( 2 ) of a vehicle ( 1 ) in order to power an Electric Motor (EM), said method comprising the steps of:
Charging the ESS from an electrical power source, e.g. the grid, when the vehicle ( 1 ) is at standstill, Stop the charging when the SOC level of the ESS (SOC ESS ) is above a maintenance limit for the SOC level of the ESS (SOC ML ), Monitoring the battery and/or performing a service operation of the ESS after the ESS has been charged to a SOC level above said maintenance limit for the SOC level of the ESS (SOC ML ), Deliberately discharge the ESS to lower the SOC level, characterized in that the SOC level of the ESS (SOC ESS ) is reduced to a take-off limit for the SOC level of the ESS (SOC TOL ) which is set in order to allow the vehicle to be controlled to use regenerative braking for charging of the ESS under subsequent driving when the vehicle ( 1 ) is restarted and takes off.

2 . A method according to claim 1 , characterized in that the method further comprises the features of:
Setting the take-off limit for the SOC level of the ESS (SOC TOL ) such that it allows the EM to be decelerated while the braking energy from deceleration of the EM is used in order to charge the ESS without reaching a driving limit for the SOC level of the ESS (SOC DL ) under subsequent driving when the vehicle is used according to a predicted driving sequence.

3 . A method according to claim 1 or 2 , characterized in that the method further comprises the features of:
Discharging the ESS to be below the take-off limit for the SOC level of the ESS (SOC TOL ) before there is an upshift from the starting gear when the vehicle is started and driven after the charging, said take-off limit for the SOC level of the ESS ( SOCTOL ) being set such that the increase of SOC level of the ESS (SOC ESS ) due to charging of the ESS by regenerative braking of the EM during the upshift not causes the SOC level of the ESS (SOC ESS ) to reach a driving limit for the SOC level of the ESS (SOC DL ).

4 . A method according to claim 1 or 2 , characterized in that the method further comprises the features of:
Setting the take-off limit for the SOC level of the ESS (SOC TOL ) in dependence of a predicted charging and discharging sequence of the ESS for a known or predicted route to be driven by the vehicle and controlling the SOC level of the ESS (SOC ESS ) to be below the take-off limit for the SOC level of the ESS (SOC TOL ) when the vehicle is started and driven after the charging in order to avoid the SOC level of the ESS (SOC ESS ) to reach a driving limit for the SOC level of the ESS (SOC DL ) due to charging of the ESS by regenerative braking.

5 . A method according to any previous claims, characterized in that the method further comprises the features of:
Balancing of the cells is performed as a service operation of the ESS after the ESS has been charged to a SOC level above said maintenance limit for the SOC level of the ESS (SOC ML ).

6 . A method according to any previous claims, characterized in that the method further comprises the features of:
Using electrical energy from the discharge of the ESS, in which the SOC level of the ESS (SOC ESS ) is lowered from being above said maintenance limit for the SOC level of the ESS (SOC ML ) to be below a take-off limit for the SOC level of the ESS (SOC TOL ), to charge a starter battery.

7 . A method according to any previous claims, characterized in that the method further comprises the feature of:
Discharging of the ESS to lower the SOC level of the ESS (SOC ESS ) to be below a take-off limit for the SOC level of the ESS (SOC TOL ) is performed before the vehicle is restarted, e.g. by discharging the ESS right after the monitoring and/or service operation of the ESS above said maintenance limit for the SOC level of the ESS (SOC ML ).

8 . A method according to any of claims 1 - 6 , characterized in that the method further comprises the features of:
Discharging of the ESS to lower the SOC level of the ESS (SOC ESS ) to be below a take-off limit for the SOC level of the ESS (SOC TOL ) is performed when the vehicle is restarted during vehicle start-up.

9 . A method according to any previous claims, characterized in that the method further comprises the features of:
Only said electrical propulsion system, electrically connected to said ESS, is used when the vehicle is restarted after the charging.

10 . A computer program comprising program code means for performing the steps of any of claims 1 to 9 when said program is run on a computer.

11 . A computer readable medium carrying a computer program comprising program code means for performing the steps of any of claims 1 to 9 when said program product is run on a computer.

12 . A control unit for controlling an electrical Energy Storage System (ESS), the control unit being configured to perform the steps of the method according to any of claims 1 to 9 .

13 . A control system for a vehicle provided with an electrical propulsion system comprising an Electric Motor (EM) electrically connected to an electrical Energy Storage System (ESS) and a control unit connected to the electrical propulsion system, characterized in that it comprises a control unit according claim 12 .

14 . A vehicle, characterized in that it comprises a control system according to claim 13 .

15 . A vehicle according to claim 13 , characterized in that the vehicle is a Hybrid Electrical Vehicle (HEV), e.g. a heavy duty vehicle such as a truck or bus.

Assignees

• Volvo Truck Corp

Inventors

• Smidebrant Tobias

Classifications

• B60L2200/40

  Working vehicles · CPC title

• B60L2240/54

  related to batteries · CPC title

• B60L50/51

  characterised by AC-motors · CPC title

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• B60L7/10

  Dynamic electric regenerative braking (B60L7/22 takes precedence) · CPC title