The invention generally relates to a machine with an electric drive and an energy storage system for the intermediate storage of recovered energy. The invention relates in particular to machines that function statically or quasi-statically with a primary electric drive and a secondary hydraulic drive that function in cyclical movements, such as in the form of a material-transferring device like an excavator or crane, having an electric drive with at least one electric motor for driving the drive train of the machine and with an energy storage system for the intermediate storage of reverse power released during towing and/or braking operation and transferred from the drive train to the electric motor. The invention also further relates to a method for operating a machine with an electric drive, in which energy recovered during a towing or braking operation is used to compensate for system losses or is stored temporarily. It is proposed that at least most of the energy transferred from the drive train back to the electric motor not be converted into electric energy, but rather that it be stored in the form of kinematic energy and that, to this end, the electric motor be put into a state with regard to its electromagnetic resistance and/or its torsional or drag torque in which the drag resistance or the electromagnetic torque of the motor is largely eliminated or at least significantly reduced relative to regular motor and/or generator operation.

Disclosed is a winch control apparatus for a crane, which comprises: a first compensation torque value calculation section which calculates, when a hoisting manipulation being input, based on a difference speed between a detected rotational speed and a target speed according to a manipulation amount of the hoisting manipulation, a first compensation torque value for enabling an electric motor to generate a reverse-rotation-preventing torque which is a torque in a hoisting direction and corresponding to the difference speed; and a second compensation torque value calculation section which calculates, when the hoisting manipulation being input, based on a detected load value, a second compensation torque value for enabling the electric motor to generate a load bearing torque which is a torque in the hoisting direction and necessary for bearing a load of the load value.

An apparatus for collecting energy in connection with a sheave system in a hoisting apparatus provided with a sheave system. The apparatus includes at least one generator including a rotor and at least one stator. The rotor is connected rigidly to a sheave of the sheave system, and the at least one stator is connected rigidly to the sheave system such that when the load of the hoisting apparatus is rising or lowering, said at least one sheave rotates, whereby the rotor rotates simultaneously but the stator does not rotate, whereby electric energy is induced in the stator. The apparatus further includes electric energy storage, a device for modifying induced electric energy and storing it in energy storage; and a device for supplying energy from the energy storage to at least one consumption device. The consumption device may be, for example, a working lamp, sensor, measuring device, communications device, signal device, charging plug or a combination of these mounted in connection with the sheave system.

An apparatus for collecting energy in connection with a sheave system in a hoisting apparatus provided with a sheave system. The apparatus includes at least one generator including a rotor and at least one stator. The rotor is connected rigidly to a sheave of the sheave system, and the at least one stator is connected rigidly to the sheave system such that when the load of the hoisting apparatus is rising or lowering, said at least one sheave rotates, whereby the rotor rotates simultaneously but the stator does not rotate, whereby electric energy is induced in the stator. The apparatus further includes electric energy storage, a device for modifying induced electric energy and storing it in energy storage; and a device for supplying energy from the energy storage to at least one consumption device. The consumption device may be, for example, a working lamp, sensor, measuring device, communications device, signal device, charging plug or a combination of these mounted in connection with the sheave system.

One three-phase transformer (71A) out of two paired three-phase transformers among three-phase transformers provided for respective feeder lines outputs, as operating power, first three-phase AC power of the same voltage phase as that of power-supply power. The other three-phase transformer (71B) out of the two paired three-phase transformers outputs, as the operating power, second three-phase AC power of a voltage phase shifted by /6 from that of the power-supply power. The power storage device (4) of a crane apparatus (10) stores DC power supplied from a three-phase full-wave rectifier (1) to a common bus (B), and supplies the stored power to the common bus (B) upon reduction of the DC power.

One three-phase transformer (71A) out of two paired three-phase transformers among three-phase transformers provided for respective feeder lines outputs, as operating power, first three-phase AC power of the same voltage phase as that of power-supply power. The other three-phase transformer (71B) out of the two paired three-phase transformers outputs, as the operating power, second three-phase AC power of a voltage phase shifted by /6 from that of the power-supply power. The power storage device (4) of a crane apparatus (10) stores DC power supplied from a three-phase full-wave rectifier (1) to a common bus (B), and supplies the stored power to the common bus (B) upon reduction of the DC power.

A hydraulic system adapted to recover inertial energy is disclosed. The hydraulic system includes a pump, a variable displacement pump/motor having an input/output shaft, an accumulator, and a valve arrangement. The valve arrangement is operable in: a) a first mode where the variable displacement pump/motor is driven by the pump to rotate the input/output shaft and the load; b) a second mode where the variable displacement pump/motor uses inertial energy from a deceleration of the load to charge the accumulator; and c) a third mode where the variable displacement pump/motor is driven by the accumulator to rotate the input/output shaft and the load. The hydraulic system also includes a controller for controlling operation of the pump, the variable displacement pump/motor and the valve arrangement.

A hydraulic system adapted to recover inertial energy is disclosed. The hydraulic system includes a pump, a variable displacement pump/motor having an input/output shaft, an accumulator, and a valve arrangement. The valve arrangement is operable in: a) a first mode where the variable displacement pump/motor is driven by the pump to rotate the input/output shaft and the load; b) a second mode where the variable displacement pump/motor uses inertial energy from a deceleration of the load to charge the accumulator; and c) a third mode where the variable displacement pump/motor is driven by the accumulator to rotate the input/output shaft and the load. The hydraulic system also includes a controller for controlling operation of the pump, the variable displacement pump/motor and the valve arrangement.

An energy storage and delivery system includes an elevator operable to move blocks from a lower elevation to a higher elevation to store energy and from a higher elevation to a lower elevation to generate electricity. A winch assembly is movably coupled to a cable that is coupled to the elevator. The winch assembly has planetary gear assemblies, brakes that selectively engage at least a portion of the planetary gear assemblies, and a spool coupled to the cable. A drive shaft extends between a motor-generator and the winch assembly. A brake is operable so that the spool rotates to reel-in the cable to raise the elevator to move a block from a lower elevation to a higher elevation to store energy or so that the spool rotates to reel-out the cable to lower the elevator to move a block from a higher elevation to a lower elevation to generate electricity.

The present invention discloses a double-power energy saving system of rubber tire gantry crane (RTG), which is composed of a controller, a battery pack, a generator set and so on. The system changed the power supply mode of traditional RTG which is powered by a single generator set or a superposition of a generator set and a battery pack. Both the battery pack and the generator set of the system can support the RTG operations independently, forming the double-power energy saving system to improve the equipment reliability. The battery pack is used as the primary power source for RTG and the output power can be highly matched with the demanded power, which reduces the reactive loss and increases the energy efficiency. The generator set is shut down and the power is supplied by the battery pack when the electricity of the battery pack is high; the generator set is started to supply power directly for RTG when the electricity of the battery pack is low, and the surplus energy can charge the battery pack. Once the battery pack is put into operation, it will run in the best economical fuel consumption area to achieve the highest fuel efficiency. The feedback energy of RTG can be fully recovered because the charging power of the battery pack is larger than the maximum feedback energy power of RTG. It is not required to replace the original generator set of RTG when the system is applied to RTG transformations.