Abstract: A combined electric power generations' supply system includes an AC power generator that supplies power by off grid independent operation, a DC power supply device, an inverter that converts DC power output by the DC power supply device into AC power. The rotation calculation unit calculates a value relating to a rotation of a rotor when driving the virtual power generator according to an active power command based on a rotor model calculates a value relating to the rotation of the rotor of the virtual power generator and the active power command. The output determination unit determines values relating to an active power and a reactive power to be output to the inverter based on the calculated value relating to the rotation. The modulation control unit performs control of a pulse width modulation of the inverter based on the determined value relating to the active power and reactive power.

Abstract: This command generation device generates a control command for a power conversion device which converts DC power outputted by a DC power supply device to AC power and supplies the same to a bus, and which converts AC power from the bus to DC power and supplies the same to the DC power supply device.

Abstract: A combined electric power generations' supply system includes an AC power generator that supplies power by off grid independent operation, a DC power supply device, an inverter that converts DC power output by the DC power supply device into AC power. The rotation calculation unit calculates a value relating to a rotation of a rotor when driving the virtual power generator according to an active power command based on a rotor model calculates a value relating to the rotation of the rotor of the virtual power generator and the active power command. The output determination unit determines values relating to an active power and a reactive power to be output to the inverter based on the calculated value relating to the rotation. The modulation control unit performs control of a pulse width modulation of the inverter based on the determined value relating to the active power and reactive power.

Abstract: A processing unit of a command generation device which is provided separately from a general-purpose inverter, performs following processing. A rotation calculation unit calculates a value relating to a rotation of a rotor of a virtual power generator when the virtual power generator is driven according to an active power command based on a rotor model that simulates a driving of the virtual power generator and calculates a value relating to the rotation of the rotor of the virtual power generator and an active power command. A target determination unit determines a target value of a voltage frequency and a target value of an active power based on the calculated value relating to the rotation. A command generation unit generates a control command for the inverter based on the determined target value of the voltage frequency and the target value of the active power.

Abstract: An energy recovering system of a hydraulic lift device for a battery operated industrial truck. With the system, working oil can be supplied to other hydraulic actuators while energy recovering operation is performed by the hydraulic lift device, and energy recovering efficiency is increased. A hydraulic motor (6) is disposed in a fluid path for recovering pressurized working fluid from a lift cylinder (1) via a control valve (10) to a working fluid reservoir tank (8) so that the hydraulic motor (6) is driven by the pressurized working fluid returning from the lift cylinder (1). The hydraulic motor (6) is connected to an electric motor (4) for driving a hydraulic pump (3), which supplies pressurized fluid to the lift cylinder (1), by means of a one-way clutch (7) which performs torque transmission only from the hydraulic motor (6) to the electric motor (4).

Abstract: An energy recovering system in a hydraulic lift device of a battery operated industrial truck. With the system, working oil can be supplied to other hydraulic actuators while energy recovering operation is performed by the hydraulic lift device, occurrence of pressure pulsation in the working oil can be prevented, and energy recovering efficiency is increased. The hydraulic lift device comprises a lift cylinder (1) for lifting a fork F, an electric motor (4) rotated by power supply from a battery (5), a hydraulic pump (3) for supplying pressurized oil to the lift cylinder (1), a control valve (14) disposed in a pressurized oil supply path (23), and a controller (17).

Abstract: A forklift which is capable of controlling overturning and a method of controlling safety against overturning for a forklift are provided. In a forklift having a controller (20) for controlling the traveling state of a vehicle, the controller (20) is characterized by estimating the traveling state at a predetermined time ahead and, when the vehicle velocity at that time exceeds a maximum allowable vehicle velocity before generating a likelihood of overturning, applying the brakes and, when a no-overturning state is achieved thereafter, releasing the brakes.

Abstract: An energy recovering system in a hydraulic lift device of a battery operated industrial truck. With the system, working oil can be supplied to other hydraulic actuators while energy recovering operation is performed by the hydraulic lift device, occurrence of pressure pulsation in the working oil can be prevented, and energy recovering efficiency is increased. The hydraulic lift device comprises a lift cylinder (1) for lifting a fork F, an electric motor (4) rotated by power supply from a battery (5), a hydraulic pump (3) for supplying pressurized oil to the lift cylinder (1), a control valve (14) disposed in a pressurized oil supply path (23), and a controller (17).

Abstract: An energy recovering system of a hydraulic lift device for a battery operated industrial truck. With the system, working oil can be supplied to other hydraulic actuators while energy recovering operation is performed by the hydraulic lift device, and energy recovering efficiency is increased. A hydraulic motor (6) is disposed in a fluid path for recovering pressurized working fluid from a lift cylinder (1) via a control valve (10) to a working fluid reservoir tank (8) so that the hydraulic motor (6) is driven by the pressurized working fluid returning from the lift cylinder (1). The hydraulic motor (6) is connected to an electric motor (4) for driving a hydraulic pump (3), which supplies pressurized fluid to the lift cylinder (1), by means of a one-way clutch (7) which performs torque transmission only from the hydraulic motor (6) to the electric motor (4).