Mitsubishi Heavy Industries Engine & Turbocharger, Ltd.

Mitsubishi Heavy Industries Limited

Nippon Yusoki Co., Ltd.

Fujio Eguchi

Osamu Nakakita

Masato Mitsuhashi

Masayuki Tanaka

Kensuke Futahashi

Masataka Kawaguchi

Kazuhito Kawashima

Hiroshi Satou

Keizo Ogino

Shingo Yuguchi

Michio Akao

Hiroyuki Suzuki

Hirotaka Uehara

Tomohiro Akaki

Toshiyuki Honda

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. A time constant relating to a synchronization power of the rotor model matches a time constant relating to a synchronization power of the AC power generator.

Command generation device and command generation method in multiple power generation power supply system

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. Said command generation device comprises: a virtual power generation calculation unit which simulates the driving of a virtual power generator and, on the basis of a rotor model that calculates the rotational speed of the virtual power generator, calculates the root-mean-square voltage and phase of the virtual power generator; a bus calculation unit which calculates the voltage and phase at a point of contact between the power conversion device and the bus; a phase difference angle calculation unit which calculates the phase difference angle between the phase of the virtual power generator and the phase at the point of contact; a target power determination unit which determines a target value for the effective power of the power conversion device on the basis of the root-mean-square voltage of the virtual power generator, the voltage at the point of contact and the phase difference angle; and a command generation unit which generates a control command for the power conversion device on the basis of the determined target value for the effective power.

Command generation device and command generation method

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. A time constant relating to synchronization power of the rotor model matches a time constant relating to synchronization power with the AC power generator.

Combined electric power generations' supply system in off grid independent operation

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 () for lifting a fork F, an electric motor () rotated by power supply from a battery (), a hydraulic pump () for supplying pressurized oil to the lift cylinder (), a control valve () disposed in a pressurized oil supply path (), and a controller (). The controller () controls the opening of the control valve () and rotation speed of the electric motor () which functions as an electric generator driven by the hydraulic pump () rotated by the action of the pressurized oil returning from the lift cylinder () when a load is lowered so that the generated electricity charges the battery () to recover the potential energy of the load.

Energy recovering method and system in hydraulic lift device of battery operated industrial trucks

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 () is disposed in a fluid path for recovering pressurized working fluid from a lift cylinder () via a control valve () to a working fluid reservoir tank () so that the hydraulic motor () is driven by the pressurized working fluid returning from the lift cylinder (). The hydraulic motor () is connected to an electric motor () for driving a hydraulic pump (), which supplies pressurized fluid to the lift cylinder (), by means of a one-way clutch () which performs torque transmission only from the hydraulic motor () to the electric motor ().

Energy recovering system of hydraulic lift device for battery operated industrial trucks

Growing community of inventors

Sagamihara, Japan

Fujio Eguchi