An energy storage and delivery system includes a crane elevator cage, where the crane or elevator cage is operable to move one or more blocks from a lower elevation to a higher elevation to store energy (e.g., via the potential energy of the block in the higher elevation) and operable to move one or more blocks from a higher elevation to a lower elevation (e.g., by gravity) to generate electricity (e.g., via the kinetic energy of the block when moved to the lower elevation). The energy storage system can, for example, store electricity generated from solar power as potential energy in the stacked blocks during daytime hours when solar power is available, and can convert the potential energy in the stacked blocks into electricity during nighttime hours when solar energy is not available, and deliver the converted electricity to the electrical grid.

A motor drive apparatus that can continue operation within the upper limit of system control even if a voltage drop of an AC power source occurs during operation of a motor used for a hoist or a crane is provided. The inverter control unit of the motor drive apparatus includes a speed reference setting means for setting the rotation speed of the motor, means for detecting a speed deviation between the output of the rotation speed detection means for detecting the rotation speed of the motor and the output of the speed reference setting means, means for controlling the output current of the inverter according to the output of the speed deviation. The speed reference setting means includes a correction circuit for correcting an external speed command given from outside. The correction circuit corrects the external speed command according to a deviation between a detection value of a DC voltage and a first reference value when a voltage drop signal is received from the voltage drop detection means, and makes the corrected speed command as the output of the speed reference setting means.

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.

A three-phase full-wave rectifier (21) performs full-wave rectification of three-phase AC power (11A) supplied from ground power supply equipment, and supplies obtained DC power (12A) to a common bus (B). A Δ-Y connection type three-phase transformer (2) outputs three-phase AC power (11B) of a voltage phase shifted by π/6 from the three-phase AC power (11A). A three-phase full-wave rectifier (22) performs full-wave rectification of the three-phase AC power (11B) output from the three-phase transformer (2), and supplies obtained DC power (12B) to the common bus (B).

A three-phase full-wave rectifier (21) performs full-wave rectification of three-phase AC power (11A) supplied from ground power supply equipment, and supplies obtained DC power (12A) to a common bus (B). A Δ-Y connection type three-phase transformer (2) outputs three-phase AC power (11B) of a voltage phase shifted by π/6 from the three-phase AC power (11A). A three-phase full-wave rectifier (22) performs full-wave rectification of the three-phase AC power (11B) output from the three-phase transformer (2), and supplies obtained DC power (12B) to the common bus (B).

A device recovers energy in working machines with at least one power drive actuated to move a load mass back and forth and with an energy storage system (16) absorbing the energy released in the movement of the load mass in one direction and making it available for a subsequent movement in the other direction. The energy storage system includes an accumulator cylinder (16) mechanically coupled to the load mass and storing pneumatic pressure energy for movement in one direction. For movement in the other direction, the accumulator cylinder acts as an auxiliary working cylinder supporting the power drive and converting the stored pressure energy into driving force.

A device recovers energy in working machines with at least one power drive actuated to move a load mass back and forth and with an energy storage system (16) absorbing the energy released in the movement of the load mass in one direction and making it available for a subsequent movement in the other direction. The energy storage system includes an accumulator cylinder (16) mechanically coupled to the load mass and storing pneumatic pressure energy for movement in one direction. For movement in the other direction, the accumulator cylinder acts as an auxiliary working cylinder supporting the power drive and converting the stored pressure energy into driving force.

A rubber tyred gantry crane three-power hybrid energy saving system comprising a system controller; a unidirectional AC/DC converter; a small diesel generator set having its output going to the unidirectional AC/DC converter and supplying power to a direct-current bus after rectification; a unidirectional DC/AC inverter power supply having its input end connected in parallel with the direct-current bus, and having output going to the auxiliary transformer after inversion; a battery set and its management system; an interconnection switch; a large diesel generator set; and an auxiliary transformer. Electrical equipment mainly includes a hoist frequency converter, a trolley frequency converter, a gantry frequency converter, auxiliary electrical equipment and a control power supply. The battery set and its management system are connected in parallel with the direct-current bus, provide operating power to the gantry frequency converter, the hoist frequency converter and the trolley frequency converter, and recover the feedback energy of the system.

An energy storage and delivery system includes a crane operable to move blocks from a lower elevation to a higher elevation to store energy (e.g., via the potential energy of the block in the higher elevation) and operable to move blocks from the higher elevation to the lower elevation (e.g., by gravity) to generate electricity (e.g., via the kinetic energy of the block when moved to the lower elevation). The blocks remain vertically spaced from each other, and a vertical distance between the lower elevation and the higher elevation of each of the blocks is the same.

An energy storage and delivery system includes a crane operable to move blocks from a lower elevation to a higher elevation to store energy (e.g., via the potential energy of the block in the higher elevation) and operable to move blocks from the higher elevation to the lower elevation (e.g., by gravity) to generate electricity (e.g., via the kinetic energy of the block when moved to the lower elevation). The blocks remain vertically spaced from each other, and a vertical distance between the lower elevation and the higher elevation of each of the blocks is the same.