US 9,422,141 B2Granted

System and method for managing a current flow in a lift machine

AssigneeTld (Canada) Inc.

InventorMartin Foley

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Abstract

There is provided an energy management system for managing a current flow in a machine having a lift element being vertically movable by a motor assembly. The energy management system includes a power supplying bus for supplying the motor assembly, a battery source, an energy storage device and an associated controller, and a main controller for controlling the energy-storage-device controller and thus the powering of the motor assembly, while factoring a height and a movement of the lift element. The system generally seeks to manage the energy flow between the battery, motors and supercapacitors so as to maintain the battery current as low as possible by controlling the motor's speed, to maintain the battery power demand constant over time, and to store the regenerated energy into supercapacitors in order to avoid recharging the battery during operation, as well as to maintain the supercapacitors energy level as high as possible.

Claims20

Dependent claims

An energy management system for managing a current flow in a machine having a lift element being vertically movable by a motor assembly, the energy management system comprising:

a power supplying bus for supplying the motor assembly;
a battery source being connected to the power supplying bus;
an energy storage device;
an energy-storage-device controller connected between the energy storage device and the power supplying bus, for controlling a current flow between the energy storage device and the power supplying bus;
sensors for detecting a height H and a movement of the lift element, said movement being selected from the group consisting of a lifting movement, a lowering movement and an immobile movement;
a first calculator connected to the sensors for calculating a minimum energy Emin required in the energy storage device as a function of the height H of the lift element;
a second calculator connected to the energy storage device for calculating an energy Eavailable stored in the energy storage device based on a voltage Vcap detected at terminals of the energy storage device and on a parameter of the energy storage device;
a comparator for calculating an Error where Error=Emin−Eavailable;
a third calculator for setting a lower limit Imin of a current to be drawn from the energy storage device to 0 A when the movement detected by the sensors is the immobile or lowering movement, and for calculating the lower limit Imin as a function of Error when the movement detected by the sensors is the lifting movement;
a fourth calculator for calculating an upper limit Imax of a current to be supplied to the energy storage device as a function of Error when the movement detected by the sensors is the immobile or lowering movement;
and
a main controller for controlling the energy-storage-device controller as a function of Imin, Imax, and the movement detected, to adjust the current flow between the energy storage device and the power supplying bus.

9 more elements

An energy management method for managing a current flow in a machine having a lift element being vertically operable by a motor assembly, the motor assembly being supplied with energy, through a power supplying bus, by a battery source and by an energy storage device via an energy-storage-device controller, the method comprising:

(a) detecting a height H and a movement of the lift element, said movement being selected from the group consisting of a lifting movement, a lowering movement and an immobile movement;
(b) calculating a minimum energy Emin required in the energy storage device as a function of the height H of the lift element;
(c) calculating an energy Eavailable stored in the energy storage device based on a voltage Vcap detected at terminals of the energy storage device and on a parameter of the energy storage device;
(d) calculating an error Error where Error=Emin−Eavailable;
(e) setting a lower limit Imin of a current to be drawn from the energy storage device to OA when the movement detected at (a) is the immobile or lowering movement, and calculating the lower limit Imin as a function of Error when the movement detected at (a) is the lifting movement;
(f) calculating an upper limit Imax of a current to be supplied to the energy storage device as a function of Error when the movement is the immobile or lowering movement;
and
(g) controlling the energy-storage-device controller as a function of Imin, Imax and the movement detected at (a) to manage the current flow between the energy storage device and the power supplying bus.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/880,766Filed 22 Oct 2010
Published: US 2013/0213744 A122 Aug 2013
Granted: 23 Aug 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

B66F 7/00
Lifting frames
B64F 1/322
For handling freight: cargo loaders specially adapted for loading air freight containers or palletized cargo into or out of the aircraft
B66F 7/0625
With platforms supported by levers for vertical movement: with wheels for moving around the floor
B66F 7/0633
With platforms supported by levers for vertical movement: mechanical arrangements not covered by the following subgroups