Hitachi, Ltd.

Shigeaki Namba

Seiitsu Nigawara

Masayuki Fukai

Hiroshi Kohmoto

Toshiki Kahara

Kengo Uda

Akio Ito

Kazuyuki Tsunoda

Katsuhito Shimizu

Nobuhiro Seiki

Hiroto Takeuchi

Satoshi Kusaka

Masashi Sugihara

Atsushi Honzawa

Satoshi Mizukami

Tatsuo Sakamoto

Shoji Takahashi

Katsuyoshi Takizawa

Mika Imai

Toru Kimura

Plural power storage systemsare provided in a power system. The power storage systemsare connected to a management systemvia a communication network CN. The power storage systems each include a power storage device, and a control devicefor controlling the power storage device. The control device stores performance information about the power storage system including the control device, location information indicating a location in the power system of the power storage system including the control device, and order information indicating an order of operation allocated to the power storage system including the control device. When a disturbance occurs in the power system, the control device performs a predetermined compensation operation based on the location information and the order information, and then returns to a preset stand-by state.

Power grid stabilization system and power grid stabilization method

A power supply system is structured, which has a server disposed so that it is capable of communicating through redundant communication media with a user terminal at a user site which is capable of receiving power from one power supply system selected by making a switchover among a plurality of power supply systems; the server collects information about abnormalities caused in the plurality of power supply systems through other redundant communication media from abnormality detectors disposed in a plurality of power generating plants, each of which is part of one of the plurality of power supply systems, and on a plurality of electric transmission/distribution lines, each of which is also part of one of the plurality of power supply systems; the server determines whether the power supply system from which the user is currently receiving power is normal or abnormal; if the power supply system is abnormal, the server sends, to the user terminal, information about normal power supply systems from which the user is able to receive power.

Power supply system

A monitoring and control system is provided having a control device, arranged in a central controller room, which provides commands to power distribution panel switch gear located in the field. The switch gear transmits and receives controlling and monitoring signals through wireless communication applying an evanescent mode. The switch gear has a power circuit connected to a plurality of devices to be operated. The switch gear is a panel comprising metal and non-metal surfaces, so that a portion of wireless waves in the evanescent mode travel out of the panel. A receiver is provided for monitoring the wireless waves that travel out of the panel. The wireless signals are compared with information stored in a diagnostics database, and are diagnostically evaluated to determine whether the signals are within a known normal operating range.

Power distribution panel switch gear and a monitoring and control system having a distribution panel switch gear

Method of synchronous circuit opening of generator circuit breaker, and its control apparatus

The object of the invention is to provide an electric power plant and a control apparatus therefor which can obtain an emergency power supply reliably through use of the turbine starter. Another generator different from the main generator coupled to the rotor shaft of the turbine is provided to the input side of the starter via a motor, and a control apparatus is provided for electrically connecting the starter and the generators responsive to a bus voltage from the in-house power supply unit which supplies electricity to a plurality of auxiliary equipment operating in the electric power plant. Thereby, an emergency power supply can be obtained reliably by the simple configuration of the invention without installing emergency power generation facilities such as a diesel engine, gas turbine or the like. In addition, an LCI device which has been utilized only at the time of turbine start up can be utilized advantageously also at the time of emergency when the in-house power supply is lost.

Power generation plant and control apparatus therefor

A monitoring apparatus for a power plant including a plurality of direct current sources, includes a unit for displaying a predetermined number of symbols representing the direct current sources, and a unit for changing a displayed form of a corresponding symbol when at least one physical quantity of the states of the direct current sources changes.

Monitoring apparatus for a power plant comprising direct current sources

A faulty chemical reactor in a chemical plant is removed, heat exchange is conducted between the faulty chemical reactor and a new chemical reactor with which the faulty chemical reactor is to be replaced, and then the new chemical reactor is installed at the position from which the faulty chemical reactor was previously removed.

Chemical reactor replacement method

Described is a processing system for knowledge data base in which indices representing the degrees of certainty of causal relations between an event and plural events relevant to the first-mentioned event are stored. The system has an input unit for inputting information on those actually experienced among events inferred based on the knowledge data base, an updating unit for updating the indices so that, among the plural causal relations, the certainty of the causal relation corresponding to the actually experienced event inputted by the input means is made higher relative to the certainties of the other causal relations, and a storing unit for storing back the thus-updated indices again in the knowledge data base. This allows an expert system with the processing system to perform inference with higher certainty.

Knowledge data base processing system and expert system

A consumer load receiving power from a power system is divided into a first load to which power may be interrupted if necessary to reduce demand on the power system, and a second load to which power supply may not be interrupted to reduce demand on the power system. When it is necessary to reduce demand on the power system, the power system sends a load control signal to a controller at the consumer indicating that supply of power to the first load is to be interrupted. In response to the load control signal, the controller interrupts supply of power from the power system to the first load, thereby reducing demand on the power system.

Apparatus for interrupting supply of power from power system to portion

Knowledge information generating system

In a plant for which process control is made, a margin of an operation allowable limit for a process variable is variably established according to situations for each apparatus constituting the plant. In addition, allowable upper limits of operation considering a life consumption state and an operation schedule of each apparatus are established for respective apparatus on the basis of a life of the whole plant. The life of each apparatus and the life of the whole plant are controlled with a goal to expire all equipment substantially at the same time by reflecting the allowable operating conditions of the apparatus constituting the plant on the plant control. Therefore, it is possible to realize rational and useful plant operation.

Control system for plant

There is disclosed a chemical reaction installation in which a number of chemical reaction vessels are arranged efficiently so as to decrease an installation area while keeping a good maintainability. A processing system is provided at the inside, and a multi-story construction is provided, and access for maintenance purposes can be obtained from the side of each floor of the multi-story construction.

Chemical reaction installation

In an expert system of an operating system e.g. an industrial plant it is desired to input data in the form of relationships between operating parameters of the system to a database. However, if such data are input by inexperienced users, there is the possibility of incorrect data being input. Therefore, a memory stores a plurality of fundamental rules, each being a predetermined relationship between the operating parameters. Then when a datum is input, the fundamental rule(s) corresponding to the operating parameters of the datum are investigated, and the datum is transmitted to the database when each such corresponding fundamental rule is satisfied. In a further development, prevent transmitting datum to a database when each such corresponding fundamental rule is not satisfied.

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Hitachi, Japan

Shigeaki Namba