ENERGY STORAGE SYSTEM FOR POWERING VEHICLE ELECTRIC USER DEVICES

• US 20070001616A1
• Filed: 04/25/2006
• Published: 01/04/2007
• Est. Priority Date: 05/02/2005
• Status: Active Grant

• Current Assignee: L'Energia E L'Ambiente - Enea Ente Per Le Nuove Tecnologie, Magneti Marelli Powertrain S.p.A. (Magneti Marelli S.p.A.)
• Original Assignee: L'Energia E L'Ambiente - Enea Ente Per Le Nuove Tecnologie, Magneti Marelli Powertrain S.p.A. (Magneti Marelli S.p.A.)
• Inventors: Puccetti, Angelo, Pennese, Michele
• Granted Patent: US 7,745,953 B2
• Time in Patent Office: Days
• US Class Current: 315/169.300
• CPC Class Codes: F02N 11/003 said electric motor being also used as a drive for auxiliaries, e.g. for driving transmission pumps or fuel pumps during engine stop
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop
• CPC Class Codes: F02N 11/0866 comprising several power sources, e.g. battery and capacitor or two batteries
• CPC Class Codes: F02N 15/022 the starter comprising an intermediate clutch
• CPC Class Codes: F02N 2011/0885 Capacitors, e.g. for additional power supply
• CPC Class Codes: F02N 2011/0896 Inverters for electric machines, e.g. starter-generators
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An energy storage system for powering electric user devices of a vehicle, the energy storage system having a battery; a capacitive element connected parallel to the terminals of the battery; and an inductive element connected in series to the battery, between the battery and the capacitive element; to effectively regulate power/energy flow between the battery and the capacitive element during transients, the ratio between the capacity of the battery measured in (Ah) and the capacitance of the capacitive element measured in (F) is less than 1, and the ratio between the capacity of the battery measured in (Ah) and the inductance of the inductive element measured in (μH) is less than 1.

Claims

1. An energy storage system for powering electric user devices of a vehicle;

the energy storage system comprising;

a battery;

a capacitive element connected parallel to the terminals of the battery; and

an inductive element connected in series to the battery, between the battery and the capacitive element;

the energy storage system being characterized in that, to effectively regulate power/energy flow between the battery and the capacitive element during transients;

the ratio between the capacity of the battery measured in (Ah) and the capacitance of the capacitive element measured in (F) is less than 1; and

the ratio between the capacity of the battery measured in (Ah) and the inductance of the inductive element measured in (μ

H) is less than 1.

2. An energy storage system as claimed in claim 1, wherein the ratio between the capacity of the battery measured in (Ah) and the inductance of the inductive element measured in (μ

H) is below 0.5.

3. An energy storage system (15) as claimed in claim 1, wherein the ratio between the capacity of the battery (20) measured in (Ah) and the inductance of the inductive element (22) measured in (μ

H) is below 0.25.

4. An energy storage system as claimed in claim 1, wherein the capacitance of the capacitive element is first sized, and the inductance of the inductive element is then sized as a function of the capacitance of the capacitive element.

5. An energy storage systems as claimed in claim 4, wherein the capacitance of the capacitive element is so sized to enable the capacitive element to store enough energy to power the electric user devices of the vehicle independently during a predetermined initial time interval of a discharge transient.

6. An energy storage system as claimed in claim 5, wherein the capacitive element is sized to meet the following requirements:

the maximum current withstandable by the capacitive element is greater than the maximum current supply required of the capacitive element during the initial time interval of the discharge transient;

the maximum voltage withstandable by the capacitive element is greater than the maximum charge voltage;

the energy that can be supplied by the capacitive element is greater than the energy required by the electric user devices during the initial time interval of the discharge transient;

the voltage at the terminals of the capacitive element at the end of the initial time interval of the discharge transient is greater than the minimum supply voltage of the electric user devices.

7. An energy storage system as claimed in claim 6, wherein the capacitive element is sized according to the equation:

8. An energy storage system as claimed in claims 4, wherein the capacitance of the capacitive element is so sized to enable the capacitive element to absorb energy supplied by the electric user devices of the vehicle during a predetermined initial time interval of a charge transient.

9. An energy storage system as claimed in claim 8, wherein the capacitive element is sized according to the equation:

10. An energy storage system as claimed in claim 1, wherein the inductance of the inductive element (22) is given by the equation:

L=R_T·

τ

where;

L is the inductance of the inductive element;

R_T is the total resistance equal to the sum of the internal resistance RB of the battery and the resistance RL of the inductive element 22;

τ

is the time constant of the series branch defined by the battery and the inductive element, and ranges between ⅓ and

⅕

of the predetermined initial time interval of a discharge transient.

11. An energy storage system as claimed in claim 10, wherein the time constant of the series branch defined by the battery and the inductive element equals ¼

of the predetermined initial time interval of a discharge transient.

12. An energy storage system as claimed in claim 1, wherein the duration of the initial time interval of a discharge transient is determined as a function of the time pattern of the current supply required of the energy storage system during the discharge transient, and as a function of a desired maximum current supply by the battery during the discharge transient.

13. An energy storage system as claimed in claim 12, wherein the duration of the initial time interval of a discharge transient equals the time interval necessary for the current supply required of the energy storage system during the discharge transient to equal the desired maximum current supply by the battery during the discharge transient.

14. An energy storage system as claimed in claim 1, wherein the capacitive element comprises a module of ultracapacitor elements.

15. An energy storage system as claimed in claim 14, wherein the ultracapacitors are of the “

Electric Double Layer Capacitor”

type.

16. An energy storage system as claimed in claim 1, wherein the capacitive element comprises an equalizing circuit

17. An energy storage system as claimed in claim 1, and comprising a casing, which houses the battery, the inductive elemental, and the capacitive element, and comprises terminals for connection to an electric system of the vehicle.

18. An energy storage system for powering electric user devices of a vehicle;

the energy storage system comprising;

a battery;

a capacitive element connected parallel to the battery; and

an inductive element connected in series to the battery, between the battery and the capacitive element;

the energy storage system being characterized in that, to effectively regulate power/energy flow between the battery and the capacitive element during transients;

the capacitance of the capacitive element is so sized to enable the capacitive element to store enough energy to power the electric user devices of the vehicle independently during a predetermined initial time interval of a discharge transient;

the inductance of the inductive element is given by the equation;

L=R_T·

τ

where;

L is the inductance of the inductive element;

RT is the total resistance equal to the sum of the internal resistance RB of the battery and the resistance RK of the inductive element;

τ

is the time constant of the series branch defined by the battery and the inductive element, and ranges between ⅓ and

⅕

of the predetermined initial time interval of a discharge transient.

19. An energy storage system as claimed in claim 18, wherein the time constant of the series branch defined by the battery and the inductive element equals ¼

of the predetermined initial time interval of a discharge transient.

20. An energy storage system as claimed in claim 18, wherein the duration of the initial time interval of a discharge transient is determined as a function of the time pattern of the current supply required of the energy storage system during the discharge transient, and as a function of a desired maximum current supply by the battery during the discharge transient.

21. An energy storage system as claimed in claim 20, wherein the duration of the initial time interval of a discharge transient equals the time interval necessary for the current supply required of the energy storage system during the discharge transient to equal the desired maximum current supply by the battery during the discharge transient.

22. An energy storage system as claimed in claim 18, wherein the capacitive element is sized to meet the following requirements:

the maximum current withstandable by the capacitive element is greater than the maximum current supply required of the capacitive element during the initial time interval of the discharge transient;

the energy that can be supplied by the capacitive element is greater than the energy required by the electric user devices during the initial time interval of the discharge transient;

the voltage at the terminals of the capacitive element at the end of the initial time interval of the discharge transient is greater than the minimum supply voltage of the electric user devices.

23. An energy storage system as claimed in claim 22, wherein the capacitive element is sized according to the equation:

24. An energy storage system as claimed in claim 18, wherein the capacitance of the capacitive element is so sized to enable the capacitive element to absorb energy supplied by the electric user devices of the vehicle during a predetermined initial time interval of a charge transient.

25. An energy storage system as claimed in claim 24, wherein the capacitive element is sized according to the equation: