Load-lifting apparatus and method of storing energy for the same

• US 7,554,278 B2
• Filed: 06/13/2007
• Issued: 06/30/2009
• Est. Priority Date: 06/13/2006
• Status: Active Grant

• Current Assignee: Mi-Jack Canada, Inc. (Lanco International, Inc.)
• Original Assignee: Railpower Technologies Corp.
• Inventors: Wegner-Donnelly, Frank, Cousineau, Raymond, Mai, Serge
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US11/818,043
• Publication Number:
  US 20080048497A1
• Time in Patent Office: 748 Days
• Field of Search: None
• US Class Current: 318/375
• CPC Class Codes: B66C 13/18 Control systems or devices exclusively for rope, cable, or chain winding mechanisms B66D1/40
• CPC Class Codes: B66C 13/28 utilising regenerative braking for controlling descent of heavy loads and having means for preventing rotation of motor in the hoisting direction when load is released
• CPC Class Codes: B66C 19/007 for containers
• CPC Class Codes: Y02T 30/00 Transportation of goods or passengers via railways, e.g. energy recovery or reducing air resistance

Abstract

A load-lifting apparatus has one or more prime power sources, one or more energy storage systems and regenerative braking. Regenerative energy is recovered when the load-lifting apparatus lowers its load. The elements of the prime power sources, energy storage devices and electrical components may be distributed to provide stability for the load-lifting apparatus. The general power architecture and energy recovery method can be applied to cranes, rubber-tired gantry cranes, overhead cranes, mobile cranes, ship-to-shore cranes, container cranes, rail-mounted gantry cranes, straddle carrier cranes and elevators. In such an architecture, the energy storage system helps alleviate the power rating requirement of the prime power source with respect to the peak power requirement for lifting a load.

Claims

1. A load-lifting apparatus comprising:

i) at least one motor for driving a mechanical load-lifting device having a load-lifting average power and a load-lifting 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 load-lifting apparatus, 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 load-lifting device lowers a load, and wherein the ratio of the at least one prime power system rated power to the load-lifting peak power is between 0.2 and 0.7.

2. The-load-lifting apparatus of claim 1 wherein the electrical bus returns the regenerative braking energy to the at least one energy storage unit to increase the stored energy when the load-lifting device lowers a load.

3. The load-lifting apparatus of claim 1 wherein the electrical bus returns the regenerative braking energy to the at least one prime power system when the load-lifting device lowers a load.

4. The load-lifting apparatus of claim 1 wherein the electrical bus returns the regenerative braking energy to the at least one energy storage unit to increase the stored energy and to the at least one prime power system when the load-lifting device lowers a load.

5. The-load-lifting apparatus of claim 1 wherein the energy storage capacity is between 100 and 5,000 kW hours and the energy storage unit output power is between 50 and 2,500 kW.

6. The-load-lifting apparatus of claim 1 wherein the at least one prime power system rated power is between 50 and 5,000 kW.

7. The-load-lifting apparatus 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, AC electrical networks, power induction systems, wind turbines and a combination thereof.

8. The load-lifting apparatus 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, one or more flywheels and a combination thereof.

9. The-load-lifting apparatus of claim 1 wherein the energy storage unit forms part of a counterweight in the load-lifting apparatus.

10. The load-lifting apparatus of claim 1 wherein the load-lifting device is selected from the group consisting of cranes, rubber-tired gantry cranes, overhead cranes, mobile cranes, ship-to-shore cranes, container cranes, rail-mounted gantry cranes, straddle carrier cranes and elevators.

11. The load-lifting apparatus of claim 1 further comprising a power-dissipating load for dissipating excess regenerative braking energy on the electrical bus.

12. The load-lifting apparatus of claim 1 further comprising an auxiliary power system connected to the electrical bus.

13. The-load-lifting apparatus of claim 1 wherein the control system comprises a controller selected from the group consisting of analog devices, programmable logic controllers and computers.

14. The load-lifting apparatus of claim 1 wherein the load-lifting device is a rubber-tired gantry crane comprising legs and the at least one prime power system is mounted between a pair of said legs proximate a bottom end of said legs.

15. The load-lifting apparatus of claim 1 wherein the load-lifting device is a rubber-tired gantry crane comprising legs and the at least one energy storage unit is mounted between a pair of said legs proximate a bottom end of said legs.

16. The load-lifting apparatus of claim 1 wherein the load-lifting device is a rubber-tired gantry crane comprising legs, the at least one energy storage unit is mounted between a first pair of said legs proximate a bottom end of said first pair of legs on a first side of the gantry crane and the at least one prime power system is mounted between a second pair of said legs proximate a bottom end of said second pair of legs on an opposite side of the gantry crane.

17. The-load-lifting apparatus 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 the load-lifting device for receiving a diesel engine and a generator set.

18. The load-lifting apparatus of claim 1 wherein the at least one motor is selected from the group consisting of variable frequency drive motors, AC drive motors, and DC drive motors.

19. The load-lifting apparatus of claim 1 wherein the at least one energy storage unit provides power regulation to the at least one prime power system.

20. A method of storing energy in a load-lifting apparatus comprising the steps of:

a) providing a load-lifting apparatus comprising;

i) at least one motor for driving a mechanical load-lifting device having a load-lifting average power and a load-lifting 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 load-lifting apparatus, 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 load-lifting device lowers a load,

wherein the ratio of the at least one prime power system rated power to the load-lifting peak power is between 0.2 and 0.7.