Ebara Densan Ltd.

Ebara Corporation

Kawasaki Steel Corporation

Noboru Kinoshita

Tadashi Kataoka

Takahide Ozawa

Seiichi Ishihara

Keiichi Yoshioka

Tai Furuya

Terence McKelvey

Eishi Marui

Yoshihiro Yazawa

Masahiro Miyamoto

Masayuki Hino

Nobuo Ohashi

Hiroyuki Tamura

Tomoharu Tejima

Kaoru Nakajima

Motoyasu Sato

Shaojun Zheng

Yuji Sone

Yutaka Ono

Motoyasu Satoh

Shao-jun Zheng

Terence Mckelvey

Masayoshi Ikeda

Kazufumi Tateishi

A power supply system for supplying power to a load is provided. The system comprises power-line carriers for supplying power to the load, and a plurality of power supply units the outputs of which are parallelly connected to power-line carriers. Each of the power supply unit comprises a generator; an inverter for converting a voltage generated by the generator into an AC voltage and outputting the AC voltage; an inverter control unit for controlling the inverter, and a connection apparatus for connecting the AC voltage outputted from the inverter to the power-line carriers. The inverter controller comprises a load sharing adjuster for adjusting a shared load current supplied from the power supply unit, so that at least one of the power supply units in operation can operated at its rating condition, thereby realizing an efficiency operation.

Electric power supply system

To provide an interconnecting power generation system which can detect an abnormality in the utility power supply and can be isolated from a utility power system and can prevent damage to a turbogenerator. An interconnecting power generation system comprises: an interconnecting inverter; a voltage phase shift circuitwhich synchronizes the output voltage phase of the interconnecting inverterwith the utility power voltage phase and monitors zero crossings of the utility power voltage, and which shifts the output voltage phase from the utility power voltage phase and shifts the shifted output voltage phase to the utility power voltage phase; a phase comparatorfor comparing the voltage phase of the utility power systemand the output voltage phase of the interconnecting inverter; and an interconnection control unitwhich detects a power outage caused by an interruption of power supply from the utility power systembased on a series of a predetermined number of matching signals outputted from the phase comparatorand sends a control signal to a circuit breakerto shut off the output of the interconnecting inverterfrom the utility power system

Interconnecting power generation system

A gas turbine generating apparatus according to the present invention comprises a gas turbine capable of a high-speed operation, a permanent-magnet-type generator driven at a high speed by the gas turbine, an inverter device () for converting alternating-current power generated by the generator into commercial alternating-current power, and a system-interconnection device () for interconnecting output of the inverter device to a commercial AC power supply system (). The system-interconnection device controls the inverter device based on voltage of the commercial AC power supply system as a criterion such that output current of the inverter device is in phase with the voltage or out of phase with the voltage by a constant phase difference. A control device () is provided for operating the permanent-magnet-type generator () as a motor at a time of starting the gas turbine, and supplying alternating-current power from a direct-current power supply through the inverter device or another inverter device in addition to the inverter device to the generator for increasing a rotational speed smoothly from zero. The control device detects output current of the inverter device and controls the inverter device to keep the output current constant.

Gas turbine generating apparatus

A power generating apparatus has a power generatorfor generating AC power, a gas turbine enginefor driving the power generator, and an inverter devicefor converting the AC power into commercial AC power. The power generating apparatus includes an interconnection switch Sfor connecting an output of the inverter devicewith a commercial AC power supply system, a first voltage detectorfor detecting a DC power supply voltage Vdc-in of the inverter device, and a second voltage detectorfor detecting a full-wave rectification voltage of the commercial AC power supply system. The power generating apparatus also includes an interconnection control partfor closing the interconnection switch Swhen the DC power supply voltage of the inverter deviceexceeds the full-wave rectification voltage of the commercial AC power supply system.

Power generating apparatus

Gas turbine generator

A sheet metal made from a ferritic stainless steel alloy which has an improved corrosion resistivity and is suitable for use in manufacturing exterior building material, in particular, roofing material, by means of forming process such as roll-forming, without formation of pocket wave. The steel alloy comprises 10-32 wt % of Cr and 0.005-0.1 wt %, in total, of C and N, the balance being Fe and unavoidable impurities. The sheet metal has been processed to present a mechanical property that, when tested in a tensile test conducted for a test piece sampled in the widthwise direction of cold-rolling and measured at the elastic limit reached in the test, a strain ratio is equal to or greater than 2.5. The method of making the sheet metal comprises the steps of: cold rolling a steel slab into a sheet metal, subjecting the thus obtained sheet metal to final annealing, subjecting the sheet metal to skin-pass rolling, and, subjecting the resulting sheet metal to aging process at a temperature of 200.degree.-550.degree. C. for a time period of more than 5 seconds and less than 48 hours.

Stainless steel sheet for exterior building constituent

A sheet metal made from a ferritic stainless steel alloy which has an improved corrosion resistivity and is suitable for use in manufacturing exterior building material, in particular, roofing material, by means of forming process such as roll-forming, without formation of pocket wave. The steel alloy comprises 10-32 wt % of Cr and 0.005-0.1%, in total, of C and N, the balance being Fe and unavoidable impurities. The sheet metal has been processed to present a mechanical property that, when tested in a tensile test conducted for a test piece sample in the widthwise direction of cold-rolling and measured at the elastic limit reached in the test, a strain ratio is equal to or greater than 2.5. The method of making the sheet metal comprises the steps of: cold rolling a steel slab into a sheet metal, subjecting the thus obtained sheet metal to final annealing, subjecting the sheet metal to skin-pass rolling, and, subjecting the resulting sheet metal to aging process at a temperature of 200.degree.-550.degree. C. for a time period of more than 5 seconds and less than 48 hours.

Method of making stainless steel sheet for exterior building constituent

Motorcycle disc braking materials of a low carbon martensitic stainless

Martensitic stainless steel having excellent weldability and workability for structural use is obtained by limiting each content of carbon and nitrogen to the low value less than 0.02% and the content of nickel to less than 0.1% and by satisfying the following requirement.

Martensitic stainless steel having excellent weldability and workability

Growing community of inventors

Fujisawa, Japan

Noboru Kinoshita