Systems and Methods for Controlling Battery Performance in Hybrid Marine Propulsion Systems

• US 20110195618A1
• Filed: 08/03/2010
• Published: 08/11/2011
• Est. Priority Date: 02/08/2010
• Status: Active Grant

• Current Assignee: Brunswick Corporation
• Original Assignee: Brunswick Corporation
• Inventors: Ward, Aaron J., Arbuckle, Jason S.
• Granted Patent: US 9,533,747 B2
• Time in Patent Office: Days
• US Class Current: 440/3
• CPC Class Codes: B63H 21/17 by electric motor
• CPC Class Codes: B63H 21/20 the vessels being powered by combinations of different types of propulsion units
• CPC Class Codes: B63H 23/24 electric dynamo-electric machines H02K
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 70/5236 Renewable or hybrid-electric solutions

Abstract

A hybrid propulsion system has an internal combustion engine and an electric motor that each selectively powers a marine propulsor to propel a marine vessel. A plurality of batteries discharges current to power the motor. A controller is programmed to aggregate the recharge and/or discharge limits of plurality of batteries and then operate the system according to a method that preferably prevents internal fault and disconnection of batteries in the plurality.

Claims

1. A hybrid marine propulsion system comprising:

a marine propulsor that propels a marine vessel;

an internal combustion engine that selectively powers the marine propulsor;

an electric motor that selectively powers the marine propulsor;

a plurality of batteries that discharge current to power the electric motor; and

a controller that operates the system in a plurality of modes including at least a charge mode in which output of the internal combustion engine is used to generate current to charge the plurality of batteries;

wherein in charge mode a battery in the plurality of batteries disconnects from the electric motor if more than a limited amount of current is received by that respective battery;

wherein the controller calculates a cumulative charge limit for the plurality of batteries by aggregating the limited amounts of current of the plurality of batteries, and then controls operation of the system in charge mode so as not to exceed the cumulative charge limit, thereby preventing disconnection of the plurality of batteries.

2. A system according to claim 1, wherein the controller operates the system in charge mode so that a negative motor torque for recharging the plurality of batteries is equal to or less than a maximum allowed negative motor torque (T) calculated based upon the cumulative charge limit.

3. A system according to claim 2, wherein the controller calculates the maximum allowed negative motor torque (T) by solving the equation:

T=P*60/(RPM*2*pi*N)

where (P) is a maximum allowable recharge power of the plurality of batteries, (RPM) is the speed of the electric motor, and (N) is the number of internal combustion engines running in the system.

4. A system according to claim 3, wherein the controller calculates the maximum allowable recharge power (P) by solving the equation:

P=(I*V)

where (I) is the cumulative charge limit and (V) is the cumulative voltage of the plurality of batteries.

5. A system according to claim 1, further comprising a plurality of internal combustion engines, each having an associated generator for charging the plurality of batteries.

6. A system according to claim 1, wherein each battery in the plurality of batteries has an internal fault mechanism that causes the battery to disconnect from the system when the limited amount of current of that respective battery is exceeded.

7. A system according to claim 1, wherein the controller comprises a plurality of sections interconnected via a controller area network, each section in the plurality of sections performing different controller functions and communicating with other sections in the plurality of sections via the controller area network.

8. A system according to claim 7, wherein the plurality of sections comprises a calculation section that calculates the cumulative maximum charge limit by aggregating the limited amounts of current of the plurality of batteries.

9. A method of operating a hybrid propulsion system having an internal combustion engine and an electric motor that each selectively power a marine propulsor to propel a marine vessel, the method comprising:

providing a plurality of batteries that discharge current to power the electric motor;

generating current from output of the internal combustion engine to charge the plurality of batteries, wherein a battery in the plurality of batteries disconnects from the electric motor if more than a limited amount of current is received by that respective battery;

operating a controller to aggregate the limited amounts of current of the plurality of batteries; and

operating the system so as not to exceed the aggregated amount of current of the plurality of batteries, thereby preventing disconnection of the plurality of batteries.

10. A method according to claim 9, comprising operating the system so as to limit a negative motor torque request to equal to or less than a maximum allowed negative motor torque (T) calculated based upon the aggregated amount of current of the plurality of batteries.

11. A hybrid marine propulsion system comprising:

a marine propulsor that propels a marine vessel;

an internal combustion engine that selectively powers the marine propulsor;

an electric motor that selectively powers the marine propulsor;

a plurality of batteries that discharge current to power the electric motor; and

a controller that operates the system in a plurality of modes including at least one of an electric mode in which the electric motor powers the marine propulsor and a boost mode in which both the internal combustion engine and the electric motor provide power to the marine propulsor;

wherein each battery in the plurality of batteries disconnects from the electric motor if it discharges more than a limited amount of current;

wherein the controller calculates a cumulative discharge limit for the plurality of batteries by aggregating the limited amounts of current of the plurality of batteries and then operates the system so as not to exceed the cumulative discharge limit, thereby preventing disconnection of the plurality of batteries.

12. A system according to claim 11, wherein the controller operates the system so that a motor torque requiring discharge of current from the plurality of batteries is equal to or less than a maximum allowed motor torque (T) calculated based upon the cumulative discharge limit.

13. A system according to claim 12, wherein the motor torque requiring discharge of current from the plurality of batteries is a requested motor torque for operating boost mode.

14. A system according to claim 12, wherein the motor torque requiring discharge of current from the plurality of batteries is an allowed motor torque for operating electric mode.

15. A system according to claim 12, wherein the controller calculates the maximum allowed motor torque (T) by solving the equation:

P*60/(RPM*2*pi*N)

where (P) is a maximum allowable discharge power of the plurality of batteries, (RPM) is the speed of the electric motor, and (N) is the number of internal combustion engines running in the system.

16. A system according to claim 15, wherein the controller calculates the maximum allowable discharge power (P) by solving the equation:

P=(I*V)

where (I) is the cumulative discharge limit and (V) is the cumulative voltage of the plurality of batteries.

17. A system according to claim 11, further comprising a plurality of internal combustion engines, each connectable to an associated generator for charging the plurality of batteries.

18. A system according to claim 11, wherein each battery in the plurality of batteries has an internal fault mechanism that causes the battery to disconnect from the system when the limited amount of current of that respective battery is exceeded.

19. A system according to claim 11, wherein the controller comprises a plurality of sections interconnected via a controller area network, each section in the plurality of sections performing different controller functions and communicating with other sections in the plurality of sections via the controller area network.

20. A system according to claim 19, wherein the plurality of sections comprises a calculation section that calculates the cumulative maximum discharge limit by aggregating the limited amounts of current of the plurality of batteries.

21. A method of operating a hybrid propulsion system having an internal combustion engine and an electric motor that each selectively power a marine propulsor to propel a marine vessel, the method comprising:

providing a plurality of batteries that discharge current to power the electric motor;

operating the electric motor to draw current from the plurality of batteries, wherein a battery in the plurality of batteries disconnects from the electric motor if more than a limited amount of current is discharged by that respective battery;

operating a controller to aggregate the limited amounts of current of the plurality of batteries; and

operating the system so as not to exceed the aggregated amount of current of the plurality of batteries, thereby preventing disconnection of the plurality of batteries.

22. A method according to claim 21, comprising operating the system so that a motor torque requiring discharge of current from the plurality of batteries is equal to or less than a maximum allowed motor torque (T) calculated based upon the cumulative discharge limit.

23. A method according to claim 22, wherein the motor torque requiring discharge of current from the plurality of batteries is a requested motor torque for operating a boost mode in which both the internal combustion engine and electric motor provide power to the marine propulsor.

24. A method according to claim 22, wherein the motor torque requiring discharge of current from the plurality of batteries is an allowed motor torque for operating an electric mode in which the electric motor powers the marine propulsor.