Hitachi, Ltd.

Hitachi Construction Machinery Co., Ltd.

Nec Corporation

Masatoshi Yoshimura

Noriaki Hino

Naohiro Kusumi

Tomofumi Shiraishi

Aung Ko Thet

Satoru Kaneko

Seiji Ishida

Toshihiko Watanabe

Kazuo Nishihama

Hiroyuki Kobayashi

Noritaka Itou

Satoshi Sekino

Kosuke Matsuo

Tokuma Ikegami

Mamoru Kimura

Toshihiko Ishida

Katsuhiko Tokuda

The work vehicleincludes a main controllerthat controls a travel driving force and a work driving force. The main controllerincludes a travel remaining time calculating unitthat calculates a remaining time until a target rise/run distance is reached as a travel remaining time t, a work remaining time calculating unitthat calculates a remaining time until a target arm angle is reached as a work remaining time t, a rise/run determining unitthat determines whether rise/run is being performed or not, a correction rate setting unitthat sets a travel correction rate ηthat adjusts a travel driving torque and a work correction rate ηthat adjusts a work driving torque based on the travel remaining time t, the work remaining time t, and the rise/run determination flag, and an engine torque distribution calculating unitthat calculates a travel driving torque command and a work driving torque command based on the travel correction rate ηand the work correction rate η.

Work vehicle apparatus for loading efficiency

A work vehicle includes: an engine; a hydraulic pump that is driven by the engine; hydraulic cylinders that are extended and contracted by pressurized fluid delivered from the hydraulic pump; a work device that is moved according to the extension/contraction operations of the hydraulic cylinders; a travel device that is driven independently of the work device; an electrically driven motor that is driven by electric power generated by the engine to operate the travel device; and a controller that controls the hydraulic cylinders and the electrically driven motor. The controller controls the output power of the hydraulic pump and the output power of the electrically driven motor by changing the distribution ratios of a first torque consumed by the work device and a second torque consumed by the travel device among torques output by the engine, on the basis of a reaction force received by the vehicle body.

Work vehicle having a controller that controls the hydraulic cylinders and the electrically driven motor on a basis of a distribution ratio of a first torque and a distribution ratio of a second torque

An object of the present invention is to provide a drive system for a dump truck capable of suppressing increase in size of a converter that controls a two-winding induction generator. To this end, the drive system for a dump truck includes a DC-DC converter connected to a main side DC bus and an auxiliary side DC bus, and a controller controls the DC-DC converter such that electric power of the main side DC bus is supplied to the auxiliary side DC bus via the DC-DC converter.

Drive system for dump truck

An object of the present invention is to provide a drive system that is provided with an induction generator having a primary winding including a main winding and an auxiliary winding and a secondary conductor, can vary the voltage of the main winding, and can increase the maximum output power of the auxiliary winding. Therefore, provided is a drive system, which is provided with an induction generator having a primary winding including a main winding and an auxiliary winding and a secondary conductor, including: a starting battery that starts the induction generator; a traction inverter that drives a traction motor; an auxiliary device inverter that drives an auxiliary device motor; a rectifier the input side of which is connected to the main winding and the output side of which is connected to the traction inverter; and a power generation inverter the output side of which is connected to the auxiliary winding and the input side of which is connected to the auxiliary device inverter and the starting battery.

Drive system having an induction generator with a main winding and auxiliary winding

It is an object of the present invention to provide a drive system including an induction generator comprising some primary windings that has a main winding and an auxiliary winding, the drive system being capable of supplying electric power required by an auxiliary inverter, even in a regenerative mode of operation in which only the auxiliary winding is energized. The maximum current value of a converter for power generating is set on the basis of the maximum output power of the auxiliary winding of the induction generator and the minimum voltage applied to the auxiliary winding unless a traction inverter is in a regenerative mode of operation, and the non-load current value of the induction generator is set such that the maximum current in the auxiliary winding under the situation of the traction inverter being in the regenerative mode of operation does not exceed the maximum current in the converter for power generating.

Drive system

The gas turbine power generation system of the present invention repeats either the supply or absorption of power, in addition to generating power. A frequency converter for converting a frequency of power is connected between the rotating electrical machine and a power system via a power line, and a controller obtains a request for an output from the gas turbine power generation system and controls the combustor on the basis of the request. With respect to the frequency converter, the controller performs frequency converter control for changing the rotational speed of the rotating electrical machine on the basis of the request. The rotating electrical machine supplies or absorbs power in accordance with the change in the rotational speed. With respect to the speed adjustment mechanism, the controller performs speed adjustment mechanism control for setting the rotational speed to a reference value.

Gas turbine power generation system, control method for gas turbine power generation system, and control device for gas turbine power generation system

A gas turbine power generation system having an improved function to stabilize the power system is disclosed. The gas turbine power generation system has a dual-shaft gas turbine, an electric generator mechanically connected to a low pressure turbine of the dual-shaft gas turbine and electrically connected to an electric power system, a rotary electric machine mechanically connected to a high pressure turbine through a compressor of the dual-shaft gas turbine and electrically connected to the electric power system, wherein a power oscillation is suppressed by operation of the rotary electric machine as a motor or as a generator.

Gas turbine power generation system and control system used in the same

There are provided a voltage command calculator that calculates a voltage command value that is a command value of an AC voltage to be applied to a rotary electric machine that is driven by a power conversion device, a carrier wave generator that generates a carrier wave, a comparator that generates a pulse signal to be supplied to the power conversion device on the basis of a comparison result between the voltage command value and the carrier wave, and a reset signal receiving unit that changes a value of the carrier wave into a predetermined value when a predetermined reset signal is input.

Control device for power conversion device, compressor drive system, flywheel power generating system, and control method of power conversion device

In order to enhance the tracking performance of power generation equipment with respect to a load variation and increase the reliability of the power generation equipment, a dynamic characteristic model simulating the dynamic characteristics of a multi-shaft gas turbine is used to calculate an output prediction value of a first power generator in a case where a combustor is controlled so as to match the output of the first power generator to an output target value; on the basis of the output target value and the output prediction value of the first power generator, a first power generator output instruction value as an instruction value for the output from the first power generator to a power system and a second power generator output instruction value as an instruction value for the output from a second power generator to the power system are calculated; and the combustor is controlled on the basis of the first power generator output instruction value and a frequency convertor is controlled on the basis of the second power generator output instruction value.

Power generation system and power generation method

A control device for power conversion device controls a power conversion device in a system driven by the power conversion device to which an electric motor outputs AC power, and includes: a control pulse generation unit configured to generate a control pulse of the power conversion device; and a negative phase creation unit configured to input a pulse signal output by the control pulse generation unit and rotational speed information of the electric motor, and to generate an inverted signal of an output signal of the control pulse generation unit, wherein the pulse signal of a half cycle during one cycle of voltage, the pulse signal being generated by the control pulse generation unit, and a pulse signal of a next half cycle during the one cycle of voltage, the pulse signal being generated by the negative phase creation unit, are symmetrical in positive and negative relationship of voltage.

Control device for power conversion device, power conversion device, electric motor drive system using said devices, compressor drive system, and gas turbine power generation system

A control device of a power converter controls a system including a converter that converts alternating current (AC) power of a power supply into direct current (DC) power, an inverter that converts the DC power into AC power, a capacitor that is charged with and discharges the DC power, and a rotary electric machine that is driven by the AC power supplied from the inverter or regenerates the AC power to the power supply, the control device including: a vibration suppression control unit that outputs a torque current command correction value for canceling an axial vibration component due to a vibration frequency of a transmission system including the rotary electric machine and an output compensation control unit that outputs a correction value for suppressing AC power of the power supply fluctuated by the vibration suppression control unit to a voltage control unit of the converter.

Control device of power converter, power conversion system, compressor driving system, flywheel power generation system, and control method for power converter

In an order wire communication control method in a bidirectional line-switched ring network system, two line terminalends located at both sides of faulty location transmit failure occurrence information utilizing APS bytes of APS protocol to other line terminalend in response to occurrence of failure in an order wire communication path on the ring network. The line terminalend where the order wire is terminated is released from termination in response to reception of the failure occurrence information of the APS bytes. Then, one of two line terminalends at both sides of the faulty location, commands termination of the order wire for the line repeater located closest to the faulty location among a plurality of line repeaters under control thereof. Thus, after release from failure, terminating control of the order wire becomes unnecessary to make it possible for all of the line terminalend to perform order wire communication.

Growing community of inventors

Tokyo, Japan

Masatoshi Yoshimura