Marine power train system and method of storing energy in a marine vehicle

• US 8,244,419 B2
• Filed: 10/24/2007
• Issued: 08/14/2012
• Est. Priority Date: 10/24/2006
• Status: Active Grant

• Current Assignee: Mi-Jack Canada, Inc. (Lanco International, Inc.)
• Original Assignee: Mi-Jack Canada, Inc. (Lanco International, Inc.)
• Inventors: Wegner-Donnelly, Frank, Watson, John David
• Primary Examiner(s): Trammell, James P
• Assistant Examiner(s): ALSOMIRI, MAJDI A
• Application Number:
  US11/923,254
• Publication Number:
  US 20080182466A1
• Time in Patent Office: 1,756 Days
• Field of Search: 701/21, 440/84
• US Class Current: 701/21
• CPC Class Codes: B63H 23/24 electric dynamo-electric machines H02K
• CPC Class Codes: B63J 3/02 from propulsion power plant
• CPC Class Codes: B63J 3/04 from power plant other than propulsion power plant
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A marine power system comprises a motor for providing propulsion. It also comprises an energy storage unit (ESU) for storing and supplying energy to the motor. A prime power system is connected to the ESU and motor for selectively providing energy to these subsystems through a bus. The motor selectively receives energy from the prime power system and the ESU and can supply regenerative braking energy to the bus. The system can also accommodate multiple generator sets providing system power. The ESU can also provide starting power for the prime power system. Alternately, the prime power system drives a mechanical power system output shaft connected to the motor, and the marine system comprises an alternator driven by the prime power system output shaft. The ESU can transmit energy to the alternator. The prime power system can be located on a tugboat displacing a barge carrying the energy storage unit.

Claims

1. A marine power system comprising:

i) at least one motor for driving a propulsion unit having a propulsion unit average power and a propulsion unit peak power;

ii) at least one energy storage unit for storing electric energy and supplying said electric energy to the at least one motor, having an energy storage capacity and an energy storage unit output power;

iii) at least one prime power system having a prime power system rated power, being electrically connected to the at least one energy storage unit and the at least one motor for selectively providing electrical energy to the at least one energy storage unit and to the at least one motor;

iv) a bus electrically connecting the at least one energy storage unit, the at least one prime power system and the at least one motor; and

v) a control system for controlling the operation of the at least one prime power system and the propulsion unit, and for monitoring the at least one energy storage unit,

wherein the at least one motor selectively receives operational energy from the at least one energy storage unit and the at least one prime power system, the at least one motor supplies regenerative braking energy to the bus when the propulsion unit collects energy from water passing by the propulsion unit, and wherein the ratio of the at least one prime power system rated power to the propulsion unit peak power is between 0.1 and 0.8.

2. The marine power system of claim 1, further comprising an alternator driven by the at least one prime power system, the alternator being electrically connected to the bus, wherein the at least one energy storage system provides starting power for the at least one prime power system.

3. The marine power system of claim 1, further comprising:

a plurality of electrical energy converters operable to convert energy to electrical energy having a desired electrical characteristic, the plurality of electrical energy converters comprising first and second electrical energy converters having respectively first and second output voltages and first and second output currents, the plurality of electrical energy converters being electrically connected to the bus,

wherein a plurality of prime power systems provide energy to the plurality of electrical energy converters, the plurality of prime power systems comprising first and second engines corresponding respectively to the first and second electrical energy converters;

the bus being operable to transport electrical energy from the electrical energy converters to the at least one motor, and wherein, at a selected time, the relationship between at least one of a current level and a voltage level of the bus on the one hand and at least one of the first and second output currents and the first and second output voltages of the first and second electrical energy converters on the other hand determines, at the selected time, which of the first and second engines supplies energy to the bus through the corresponding electrical energy converter.

4. The marine power system of claim 1 wherein the at least one prime power system comprises a prime power source selected from the group consisting of engines, diesel engines, gas turbine engines, microturbines, Stirling engines, spark ignition engines, fuel cells, solar cells, grid power, power induction systems, wind turbines and a combination thereof.

5. The marine power system of claim 1 wherein the energy storage unit comprises an energy storage system selected from the group consisting of a battery pack, a bank of capacitors, a compressed air storage system, a hydraulic accumulator, one or more flywheels and a combination thereof.

6. The marine power system of claim 1 wherein the energy storage unit forms part of a ballast in a marine vehicle.

7. The marine power system of claim 1 further comprising a power-dissipating load for dissipating excess regenerative braking energy on the electrical bus, wherein the power-dissipating load is mounted on a marine vehicle under water.

8. The marine power system of claim 1 further comprising an auxiliary power system connected to the electrical bus.

9. The marine power system of claim 1 wherein the control system comprises a controller selected from the group consisting of analog devices, programmable logic controllers and computers.

10. The marine power system of claim 1, wherein the at least one energy storage unit and the at least one prime power system are sized and provided in a form adapted to retrofit with an existing receiving means on a marine vehicle for receiving a diesel engine and a generator set.

11. The marine power system of claim 1 wherein the at least one energy storage unit provides power regulation to the at least one prime power system.

12. The marine power system of claim 1, wherein the propulsion unit comprises a drive system selected from the group consisting of screws, propellers, and jet pumps.

13. The marine power system of claim 1, wherein the at least one prime power system and the at least one energy storage system each comprise:

a generator operable to convert mechanical energy output by the at least one prime power system into electrical energy; and

an electrical converter operable to convert the outputted generator electrical energy into direct current electrical energy and to permit electrical energy to flow reversibly in each of two directions;

wherein, at a selected time, the at least one prime power system is turned off and the at least one energy storage system is turned on, wherein the electrical converter of the at least one energy storage system is switched to provide electrical energy to the bus at a selected voltage level, and the electrical converter of the at least one prime power system is switched to receive electrical energy from the bus at the selected voltage level, whereby the at least one prime power system is activated using electrical energy supplied, via the bus, by the at least one energy storage system.

14. The marine power system of claim 1, wherein the at least one prime power system is located on a first vessel and the at least one energy storage system is located on a second vessel being displaced by the first vessel.

15. The marine power system of claim 14, wherein the first vessel is a tugboat and the second vessel is a barge.

17. The marine power system of claim 13, wherein the at least one prime power system is located on a first vessel and the at least one energy storage system is located on a second vessel being displaced by the first vessel.

18. The marine power system of claim 17, wherein the first vessel is a tugboat and the second vessel is a barge.

21. The marine power system of claim 1, further comprising at least one supplementary regenerative braking power source electrically connected to the bus and wherein the regenerative power source supplies further regenerative braking energy to the bus.

22. The marine power system of claim 21, wherein the at least one supplementary regenerative braking power source is selected from the group consisting a winch system and a crane system.

16. A marine power system comprising:

i) at least one motor for driving a propulsion unit having a propulsion unit average power and a propulsion unit peak power;

ii) at least one prime power system driving a mechanical power system output shaft connected to the at least one motor through a mechanical transmission;

iii) at least one alternator driven by the at least one prime power system output shaft;

iv) at least one energy storage unit for storing electric energy and being connected to the at least one alternator, having an energy storage capacity and an energy storage unit output power;

v) a bus electrically connecting the at least one energy storage unit, and the at least one alternator; and

vi) a control system for controlling the operation of the at least one prime power system and the propulsion unit, and for monitoring the at least one energy storage unit,

wherein the at least one energy storage system provides starting power for the at least one prime power system, and wherein the ratio of the at least one prime power system rated power to the propulsion unit peak power is between 0.5 and 1.0.

19. A method of storing energy in a marine vehicle comprising the steps of:

a) providing a marine power system comprising;

i) at least one motor for driving a propulsion unit having a propulsion unit average power and a propulsion unit peak power;

ii) at least one energy storage unit for storing electric energy and supplying said electric energy to said at least one motor, having an energy storage capacity and an energy storage unit output power;

iii) at least one prime power system having a prime power system rated power, being electrically connected to the at least one energy storage unit and the at least one motor for selectively providing electrical energy to the at least one energy storage unit and to the at least one motor;

iv) a bus electrically connecting the at least one energy storage unit, the at least one prime power system and the at least one motor; and

v) a control system for controlling the operation of the at least one prime power system and the propulsion unit, and for monitoring the at least one energy storage unit,

b) selectively providing to the at least one motor operational energy from the at least one energy storage unit and the at least one prime power system; and

c) supplying regenerative braking energy from the at least one motor to the electrical bus when the propulsion unit collects energy from water passing by the propulsion unit, the ratio of the at least one prime power system rated power to the propulsion unit peak power being between 0.1 and 0.8.

20. The method of storing energy in a marine vehicle according to claim 19, wherein the at least one prime power system is located on a first vessel and the at least one energy storage system is located on a second vessel being displaced by the first vessel.