Multiple storage system and method for operating a multiple storage system

Patent metadata

Field	Value
Publication number	US-10814739-B2
Application number	US-201815982828-A
Country	US
Kind code	B2
Filing date	May 17, 2018
Priority date	Nov 18, 2015
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

A method operates a storage system for a vehicle. The storage system has a first storage module and a second storage module for providing electrical energy to or for receiving electrical energy from a distribution network. The distribution network is coupled to an electrical motor of the vehicle. The first storage module is coupled by a direct current voltage converter to the distribution network. The method determines whether an amount of a voltage difference between a power supply voltage of the distributor network and a first storage voltage of the first storage module is equal to or less than a voltage threshold value. The method carries out one or more measures for increasing the amount of the voltage difference when it is determined that the amount is equal to or less than the voltage threshold value.

First claim

What is claimed is:

1. A method for operating a storage system for a vehicle, the storage system comprising a first storage module and a second storage module for providing electrical energy to or for absorbing electrical energy from a distribution network, wherein the distribution network is coupled to an electric drive machine of the vehicle, and wherein the first storage module is coupled to the distribution network via a DC voltage converter, the method comprising the acts of:
determining whether a magnitude of a voltage difference between a network voltage of the distribution network and a first storage voltage of the first storage module is equal to or less than a voltage threshold value; and
when it is determined that the magnitude is equal to or less than the voltage threshold value, increasing the magnitude of the voltage difference by adjusting a division of a present load of the first storage module and a present load of the second storage module based on an electrical power requested or provided in the distribution network, wherein the present load of the first storage module is a present discharge power or charging power, and the present load of the second storage module is a present discharge power or charging power.

2. The method as claimed in claim 1 , wherein
the first storage module comprises one of a power store and an energy store and the second storage module comprises the other one of the power store and the energy store;
the power store has a higher maximum possible charging power and/or discharge power compared to the energy store; and
the energy store has a higher energy density and a higher storage capacity compared to the power store.

3. The method as claimed in claim 2 , wherein
the first storage module comprises the energy store and the second storage module comprises the power store.

4. The method as claimed in claim 3 , wherein the method further comprises the acts of:
determining that electrical power is requested or provided in the distribution network; and
controlling the DC voltage converter such that the electrical power is provided or absorbed to a greater extent by the power store.

5. The method as claimed in claim 4 , wherein the method further comprises the acts of:
determining that a cumulative foregone load of the power store has reached or exceeded a load threshold value;
determining that electrical power is provided in the distribution network; and
controlling the DC voltage converter such that a present charging power of the power store for absorbing the electrical power provided in the distribution network is reduced compared to a maximum possible charging power of the power store.

6. The method as claimed in claim 2 , wherein the method further comprises the acts of:
determining that electrical power is requested or provided in the distribution network; and
controlling the DC voltage converter such that the electrical power is provided or absorbed to a greater extent by the power store.

7. The method as claimed in claim 2 , wherein the method further comprises the acts of:
determining that a cumulative foregone load of the power store has reached or exceeded a load threshold value;
determining that electrical power is provided in the distribution network; and
controlling the DC voltage converter such that a present charging power of the power store for absorbing the electrical power provided in the distribution network is reduced compared to a maximum possible charging power of the power store.

8. The method as claimed in claim 2 , wherein
the method comprises determining a driving mode from a multiplicity of driving modes in which the vehicle is currently being operated;
the multiplicity of driving modes comprises a sport mode and/or a consumption-oriented mode; and
the method further comprises controlling the DC voltage converter depending on the driving mode.

9. The method as claimed in claim 8 , wherein
in the sport mode, the vehicle is intended to have an increased acceleration capability compared to the consumption-oriented mode;
in the sport mode, a setpoint state of charge of the power store is higher over a total driving speed range of the vehicle than in the consumption-oriented mode; and
the method further comprises controlling the DC voltage converter such that the power store has the setpoint state of charge.

10. The method as claimed in claim 9 , wherein
in the consumption-oriented mode, the vehicle is intended to have an increased electrical energy efficiency compared to the sport mode; and
the method further comprises:
determining, in response to a request for or provision of electrical power in the distribution network, a division of power between the first storage module and the second storage module, as a result of which total power losses of the first storage module, of the second storage module and of the DC voltage converter are reduced; and
controlling the DC voltage converter depending on the determined power division.

11. The method as claimed in claim 2 , the method further comprising the acts of:
determining that an increased electrical power is requested or provided in the distribution network; and
limiting an increase in a power that is convertable by the DC voltage converter such that a non-converted remaining portion of the increased electrical power does not exceed a maximum discharge or charging power of the power store.

12. The method as claimed in claim 1 , wherein
the method comprises determining a driving mode from a multiplicity of driving modes in which the vehicle is currently being operated;
the multiplicity of driving modes comprises a sport mode and/or a consumption-oriented mode; and
the method further comprises controlling the DC voltage converter depending on the driving mode.

13. The method as claimed in claim 12 , wherein
in the consumption-oriented mode, the vehicle is intended to have an increased electrical energy efficiency compared to the sport mode; and
the method further comprises:
determining, in response to a request for or provision of electrical power in the distribution network, a division of power between the first storage module and the second storage module, as a result of which total power losses of the first storage module, of the second storage module and of the DC voltage converter are reduced; and
controlling the DC voltage converter depending on the determined power division.

14. The method as claimed in claim 1 , wherein the magnitude of the voltage difference is also increased by one or more of transferring electrical energy between the first storage module and the second storage module, and limiting a present discharge power or charging power of one of the two storage modules.

15. A storage system for a vehicle, comprising:
a first storage module and a second storage module for providing electrical energy to or for absorbing electrical energy from a distribution network, which is coupled to an electric drive machine of the vehicle;
a DC voltage converter, which couples the first storage module to the distribution network, wherein
the DC voltage converter is configured to convert electrical energy between a first storage voltage of the first storage module and a network voltage of the distribution network, and
the DC voltage converter comprises either a step-up converter or a step-down converter; and
a control unit, which is operatively configured to:
determine whether a magnitude of a voltage difference between a network voltage of the distribution network and a first storage voltage of the first storage module is equal to or less than a v

Assignees

• Bayerische Motoren Werke Ag

Inventors

• Molina Vincent
• Schmitz Andre
• Fritzsche Pablo
• Bauer Frank
• Meinert Hajo

Classifications

• Y02T90/14

  Plug-in electric vehicles · CPC title

• Y02T10/7072

  Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors · CPC title

• B60L58/12 Primary

  responding to state of charge [SoC] · CPC title

• B60L58/20

  having different nominal voltages · CPC title

• Y02T10/70

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