Abstract: A method of identifying an instruction combination executable by a surface control system of a drilling rig to change settings of a rotary steerable system (“RSS”) tool. The method includes identifying, by an electronic application, a first current RSS setting of the RSS tool; identifying, by the electronic application, a first target RSS setting of the RSS tool; identifying, by the electronic application, a plurality of instruction combinations configured to change the first current RSS setting to the first target RSS setting. Each instruction combination of the plurality of instruction combinations comprises a number of steps, and each step includes a downlink command sequence. The method also includes selecting, by the electronic application, an instruction combination that comprises the least number of steps.

Abstract: A complete telemetry system and methods for downhole operations. The telemetry system includes an instrumented near-bit sub located below the Mud Motor and connected to the drill bit as well as a conventional MWD tool located above the mud motor. Parameters such as inclination of the borehole, the natural gamma ray of the formations, the electrical resistivity of the formations, and a range of mechanical drilling performance parameters are measured. Electromagnetic telemetry signals representing these measurements are transmitted uphole to a receiver associated with the conventional MWD tool located above the motor, and transmitted by this tool to the surface via mud pulse signals. The system is particularly useful for accurate control over the drilling of extended reach and horizontally drilled wells.

Abstract: A sensor node system for mapping hydraulic fractures may include a localization system that identifies location information of the sensor node device with respect to an area of interest in a rock formation. The location information may include various magnetization parameters indicative of various signal strengths surrounding the sensor node device. The sensor node device may include a transceiver that exchanges signals with a base station and at least one other sensor node device. The transceiver establishes a communication link between the base station and the sensor node device. The transceiver may monitor at least one other communication link between the at least one other sensor node device and the base station. The sensor node device may include a processor that identifies distance information based on the location information and a predetermined number of signals associated to the various signal strengths surrounding the sensor node device.

Abstract: A well tool assembly can include a well barrier and a detachable sub connected to the well barrier. The detachable sub can include a sensor data receiver. A method of retrieving sensor data can include positioning a sensor on one side of a well barrier, connecting a detachable sub on an opposite side of the well barrier, the detachable sub including a sensor data receiver configured to receive sensor data from the sensor, and conveying the well barrier, the sensor and the detachable sub together into a well. A system can include a sensor, a detachable sub, and a well barrier positioned between the sensor and the detachable sub, the detachable sub including a sensor data receiver, a passage extending longitudinally through the detachable sub, and a closure that selectively opens and blocks the passage.

Abstract: A delayed-activation sensor system includes at least one microsensor. The microsensor may include at least one sensor module for sensing a condition in an environment and a dissolvable coating encapsulating at least a portion of the at least one sensor module such that the dissolvable coating prevents the at least one sensor module from sensing the condition in the environment. The dissolvable coating may be dissolvable in a fluid in the environment such that the sensor module is activated after being located in the environment for a period of time. The microsensor may also include at least one energy harvester module to generate electrical power for the microsensor from the environment.

Abstract: A charging device has a casing, a connector, and a supporting frame. The casing has a seat and a cover detachably deposited on the seat. The connector is connected to the casing and is deposited in the casing between the seat and the cover. The supporting frame is connected to the casing and abuts against the connector to hold the connector between the casing and the supporting frame. When the connector of the charging device needs maintenance or replacement, the supporting frame is detached from the cover and the connector is separated from the cover by a pushing force from an outer side to an inner side of the cover to replace a new connector. After replacement with the new connector, the supporting frame is connected to the cover again to finish the maintenance operation. The charging device may be detached and maintained easily.

Abstract: A mobile terminal may include a plurality of antennas to receive radio waves, a receiver circuit to receive power of the radio waves received by the plurality of antennas using a diversity technique, and a charging unit to charge a rechargeable battery coupled to the mobile terminal by the power of the radio waves received by the receiver circuit.

Abstract: A method for acquiring geophysical data includes connecting a power module comprising a data transfer port and a power transfer port to a geophysical data acquisition device to provide a geophysical sensing node and deploying the geophysical sensing node. While deployed, data is transferred from the geophysical data acquisition device to the power module via the data transfer port and power is transferred from the power module to the geophysical data acquisition device via the power transfer port. The method also includes retrieving the geophysical sensing node and replacing the power module with a newly charged power module to provide a newly charged geophysical sensing node, and deploying the newly charged geophysical sensing node. Corresponding systems are also disclosed herein.

Abstract: An Engineer's View (EV) wireless video system for powered and unpowered model railroad engines is disclosed. The invention uses commercially available wireless spy cameras, powered by a custom power supply circuit which is compatible with either DC or DCC track systems. The present invention is compatible with all commercial model railroad gauge diesel engines including HO and N Gauge or may be factory installed. The EV system demonstrates a remarkably stable and realistic image of a model railroad layout. Moreover, the present invention may also provide a stable source of power to the engine where stalling could occur at points of track defects.

Abstract: A home use sound reproduction system for Hi-fi, with digital signal transfer from a playback unit via a control unit to one or more active loudspeakers, each including or arranged beside an amplifier unit. The control unit is arranged to control sound parameters and send both a digital sound information signal and a power signal for powering the amplifier units, and to superimpose the single ended or differential digital signal together with the power signal on at least one common lead in a cable.

Abstract: An inground housing supports a transmitter for receiving electrical power from a battery. The transmitter transmits at least one signal using at least two different transmit power levels for at least one of locating the transmitter and characterizing an orientation of the transmitter. Based on detecting the battery voltage, the transmitter selects one of the transmit power levels. Transmitter output power can be controlled based on one or both of signal gain and duty cycle.

Abstract: A system for transmitting electric power into a bore hole, the system having an electric transmission line extending through the bore hole between an electric power source and a receiving station, wherein the receiving station includes frequency increasing means for increasing the frequency of the electric current supplied through the electric transmission line, voltage converter means for changing the voltage of the electric current supplied to it via the frequency increasing means, connecting means for supplying the frequency-increased electric current to the voltage converter means, and means for connecting an electric load to the receiving station.

Abstract: A sensor device integrates ZigBee® technology into power switch device to provide monitoring and control of power usage, as well as operational control of connected devices. The sensor device uses a power line communication (PLC) network to transfer collected data and to provide remote control capability to connected appliances. The sensor device, in conjunction with a master switch device, a communication enabled switching device, and the power switch device, provides an integrated home environment for communication, streaming media, monitoring, and remote control of power usage, as well as remote operational monitoring and control of connected appliances in the home.

Abstract: Wireless power receiving apparatus 150 is retrofitted to a portable electrical device 100 to enable the device to receive power wirelessly. The apparatus comprises a power-receiving element 200 adapted to be attached to the device, e.g. by adhesive 201, and also being adapted to receive power wirelessly from a transmitter of power when the element and transmitter are in proximity with one another. One or more power connectors 203 are connected electrically to the power-receiving element and are adapted to be connected, when the apparatus is in use, to one or more corresponding power connectors 101 of the portable electrical device to deliver power received by the element to the device. The power-receiving element may be in the form of a sticker or may be carried by or incorporated in a replacement cover portion for the portable electrical device.

Abstract: An apparatus and method for delivering communication and/or power downhole. The apparatus may include an information network configured to use a multi-drop deterministic protocol. The method may include delivering information over the information network. The method may include delivering power over the information network.

Abstract: Wireless power receiving apparatus 150 is retrofitted to a portable electrical device 100 to enable the device to receive power wirelessly. The apparatus comprises a power-receiving element 200 adapted to be attached to the device, e.g. by adhesive 201, and also being adapted to receive power wirelessly from a transmitter of power when the element and transmitter are in proximity with one another. One or more power connectors 203 are connected electrically to the power-receiving element and are adapted to be connected, when the apparatus is in use, to one or more corresponding power connectors 101 of the portable electrical device to deliver power received by the element to the device. The power-receiving element may be in the form of a sticker or may be carried by or incorporated in a replacement cover portion for the portable electrical device.

Abstract: The invention provides for electromagnetic transmission and reception used in detecting relative changes associated with nano devices existing within an oil reservoir. The system enables monitoring of the relative movement of the nano devices in the oil and/or water over a given area based on the incremental or relative changes of the intensity of the reflections over time. In one embodiment, a source of electromagnetic energy from an array of antennae transmitting immediately in the far field recharges a power source embedded in the nano devices. In another embodiment, the return signals from the nano devices maps the morphology of ensembles of nano devices. In yet another embodiment the transmission controls the movement of the nano devices and controls the function preformed by the nano devices relative to effecting changes in the well to improve production of oil.

Abstract: A power line communications system includes slave apparatuses individually connected to multiple electric power line wirings; a master apparatus connected to one of the multiple electric power line wirings; and couplers each connected between the master apparatus and the others of the multiple electric power line wirings. The master apparatus includes a communicator for performing power line communications with the slave apparatuses via the electric power lines; a power supply terminal device connected to the one electric power line wiring; a communication connector provided between the communicator and the power supply terminal device; and a coupler connecting terminal device connected to each of the couplers via a signal line.

Abstract: A system for single wire secondary distribution comprising a spacecraft platform; a central bus interface unit coupled to the spacecraft platform; a payload unit coupled to the central bus interface unit; and a centralized power supply for powering the central bus interface unit and the payload unit; wherein the spacecraft platform provides a command to the central bus interface unit; wherein the central bus interface unit interrupts the power to the payload unit in a manner corresponding to the commands received by the central bus interface unit; wherein the payload unit decodes the interruption to the power and executes the command from the spacecraft platform.

Abstract: A downhole communication device comprises a first energy harvesting device; a downhole transceiver in communication with the first energy harvesting device; an accumulator in communication with the energy harvesting device; and a microcontroller. The microcontroller manages communication between the first energy harvesting device, transceiver, and accumulator.

Abstract: A data logging apparatus is provided with a separate power supply for driving external sensors, a main module including an acceleration sensor, a memory unit, a control unit embedded with a clock unit for operating a measurement value of the acceleration sensor and storing the operated measurement value into the memory unit in a time series, and a first battery for supplying power to the acceleration sensor, the memory unit, and the control unit; a second battery detachably installed at one side main unit; and a sensor mounting module installed with a plurality of sensor resting units so that sensors can be attached and detached, for receiving the second battery inside so that power of the second battery can be supplied to the sensors installed in the sensor resting units, and transferring measurement signals of the sensors to the control unit.

Abstract: Wireless power receiving apparatus (150) is retrofitted to a portable electrical device (100) to enable the device to receive power wirelessly. The apparatus comprises a power-receiving element (200) adapted to be attached to the device, e.g. by adhesive (201), and also being adapted to receive power wirelessly from a transmitter of power when the element and transmitter are in proximity with one another. One or more power connectors (203) are connected electrically to the power-receiving element and are adapted to be connected, when the apparatus is in use, to one or more corresponding power connectors (101) of the portable electrical device to deliver power received by the element to the device. The power-receiving element may be in the form of a sticker or may be carried by or incorporated in a replacement cover portion for the portable electrical device.

Abstract: A data communication system for use in downhole applications wherein electrical energy is supplied over a multiple-conductor power cable to an ESP motor assembly. A downhole unit is AC-coupled to the conductors of the power cable through the wye point of the ESP motor assembly. A surface unit is AC-coupled to the conductors of the power cable. Uplink communication of telemetry data occurs over an AC communication scheme supported by the downhole unit and the surface unit. Downlink communication of remote control command data occurs over a different AC communication scheme supported by the surface unit and the downhole unit. These AC communication schemes provide an independent supply of power to the downhole environment. All communication between the surface and downhole environment is accomplished through the power cable without the use of additional communication lines. Data communication is maintained in the event of a ground fault on the power cable.

Abstract: A device for communicating with a downhole measurement tool includes a processor module comprising a set of commands and configured to issue a command from the set to the downhole tool and receive a corresponding reply from the downhole tool. The set of commands includes at least one of a command to switch the downhole measurement tool between a sleep mode and an active mode and a command to download data from the downhole measurement tool. The device includes a transceiver module coupled to the processor module and an antenna coupled to the transceiver module. The antenna and transceiver module are configured to transmit commands and replies between the processor module and the downhole measurement tool.

Abstract: Wireless power receiving apparatus (150) is retrofitted to a portable electrical device (100) to enable the device to receive power wirelessly. The apparatus comprises a power-receiving element (200) adapted to be attached to the device, e.g. by adhesive (201), and also being adapted to receive power wirelessly from a transmitter of power when the element and transmitter are in proximity with one another. One or more power connectors (203) are connected electrically to the power-receiving element and are adapted to be connected, when the apparatus is in use, to one or more corresponding power connectors (101) of the portable electrical device to deliver power received by the element to the device. The power-receiving element may be in the form of a sticker or may be carried by or incorporated in a replacement cover portion for the portable electrical device.

Abstract: Well for production of hydrocarbons, comprising a hole drilled down into an underground, a casing fastened to the hole wall, a production pipe that extends into the casing from the surface and down to a hydrocarbon-containing zone, a hanger on the surface in an upper end of the well, in which hanger the production pipe and casing are hung up and electrically short-circuited, and a packer arranged sealingly and electrically short-circuiting in the annulus between the production pipe and the casing, in or close to a lower end of the well, distinguished in that the well further comprises: a primary coil arranged concentrically about the production pipe, a secondary coil arranged concentrically about the production pipe, a load connected to the secondary coil, and an alternating current generator/signal unit connected to the primary coil.

Abstract: Various embodiments are disclosed relating to wireless transmitters, and also relating to multi-band transformers. According to an example embodiment, an apparatus may include a multi-band transformer configured to receive as an input a signal associated with a first frequency band or a signal associated with a second frequency band. The transformer may include one or more inputs and a first output and a second output. The transformer may also include one or more switches coupled to the transformer and configured to selectively output a received input signal onto the first output and/or the second output of the transformer.

Abstract: A power source for use in a downhole environment. The power source can include a microgenerator, where the microgenerator is comprised of a motive source, a rotor, a stator, and an electrical load. The motive source can be compressed gas, liquid, two-phase fluid, or combustion gases. The rotor may comprise a magnet and the stator may comprise a coil, such that rotating the rotor coaxially proximate to the stator produces electrical current. The electrical load includes any device used in downhole exploration and production that requires electrical energy.

Abstract: An operation of drilling an earth borehole uses a drilling rig, a drill string of drill pipes having its generally upper end mechanically coupleable with and suspendable from the drilling rig, a drive string portion of the drill string, mechanically coupleable with the topmost drill pipe of said drill string, and a drive mechanism mechanically coupleable with the drive string for rotating the drive string and the drill string. A system for generating electric power in the region of the drive string includes an electric generator, which includes a rotating generator component mounted on said drive string for rotation therewith and a stationary generator component mounted on a stationary portion of the drilling rig. The rotating generator component produces electric power in the region of the drive string.

Abstract: A wireless transceiver for transmitting data across a pipe joint is described herein. At least some illustrative embodiments include a wireless communication apparatus including a housing configured to be positioned inside/proximate of/to an end of a drill pipe. The housing includes an antenna with at least one RF signal propagation path parallel to the axis of the housing, and an RF module (coupled to the antenna) configured to couple to a communication cable, and to provide at least part of a data retransmission function between an antenna signal and a communication cable signal. A material (transparent to RF signals within the RF module's operating range) is positioned along the circumference, and at/near an axial end, of the housing closest to the antenna. At least some RF signals, axially propagated between the antenna and a region near said axial end, traverse the radiotransparent material along the propagation path.

Abstract: Methods and systems for energy management system for a vehicle are provided. The system includes a first power source configured for cranking an engine wherein the first power source includes a switch configured to electrically couple the first power source to a starter for the engine and wherein the first power source is electrically isolated from auxiliary onboard loads. The system further includes a second power source configured for supplying auxiliary on board loads, a charging subsystem electrically coupled to the first and the second power sources. The charging subsystem is configured to supply charging current to the first and the second power sources. The system further includes a controller configured to maintain the first power source in a substantially fully charged condition and supply the auxiliary loads from the second power source.

Abstract: The invention provides downhole communication devices and methods of using downhole communication devices. One aspect of the invention provides a downhole communication device including: a first energy harvesting device; a downhole transceiver in communication with the first energy harvesting device; an accumulator in communication with the energy harvesting device; and a microcontroller. The microcontroller manages communication between the first energy harvesting device, transceiver, and accumulator.

Abstract: The invention provides for electromagnetic transmission and reception used in detecting relative changes associated with nano devices existing within an oil reservoir. The system enables monitoring of the relative movement of the nano devices in the oil and/or water over a given area based on the incremental or relative changes of the intensity of the reflections over time. In one embodiment, a source of electromagnetic energy from an array of antennae transmitting immediately in the far field recharges a power source embedded in the nano devices. In another embodiment, the return signals from the nano devices maps the morphology of ensembles of nano devices. In yet another embodiment the transmission controls the movement of the nano devices and controls the function preformed by the nano devices relative to effecting changes in the well to improve production of oil.

Abstract: Subterranean oilfield sensor systems and methods are provided. The subterranean oilfield sensor systems and methods facilitate downhole monitoring and high data transmission rates with power provided to at least one downhole device by a light source at the surface. In one embodiment, a system includes uphole light source, a downhole sensor, a photonic power converter at the downhole sensor, an optical fiber extending between the uphole light source and the photonic power converter, and downhole sensor electronics powered by the photonic power converter. The photonic power converter is contained in a high temperature resistant package. For example, the high temperature resistant package and photonic power converter may operate at temperatures of greater than approximately 100° C.

Abstract: At least one antenna array including three mutually orthogonal antennas each sharing a common center point senses an electromagnetic signal emitted by a buried object such as a utility line, pipe or sonde. A circuit at least partially mounted in a housing is connected to the array and determines a location of the buried object by measuring signal strength and field angles in three dimensions without having to align the antenna array relative to the buried object while eliminating nulls and false peaks. A graphical user interface (GUI) has user-friendly icons, symbols, menus, numbers and graphical and auditory representation of signal strength. A plurality of different underground objects can be simultaneously detected and their different locations can be simultaneously indicated to a user via audible sounds and/or visual images on a display.

Abstract: Methods of and apparatus for a downhole communication in a well. The well has a metallic structure which includes an insulated metallic, fluid carrying, control line. The method comprises the steps of applying signals to the control line at a first location and extracting the signals from the control line at a second location. There is also provided a downhole communication system for use in a well having a metallic structure. The metallic structure includes an insulated metallic, fluid carrying, control line. The system comprises means for applying signals to the control line at a first location and means for extracting the signals from the control line at a second location. The control line acts as a signal channel. Other methods and apparatus making use of control line carrying no fluid and/or the metallic shielding of cable having insulated metallic shield are also described.

Abstract: A signal transmission method for transmitting a signal between a regulated power supply unit that operates and controls a high intensity discharge lamp and a setting unit that gives various kinds of commands to the regulated power supply unit is provided. The method includes providing the regulated power supply unit with a first communication controller; providing the setting unit with a second communication controller; providing a pair of signal lines.

Abstract: A system for transmitting power to components of a downhole drill string is disclosed in one embodiment of the invention as including a power source providing an alternating current at a first frequency. A rectifier is provided to convert the alternating current to direct current. An inverter converts the direct current to an alternating current at a second frequency, different from the first frequency, and more efficient for power transmission. An inductive coupler converts the alternating current at the second frequency to an alternating magnetic flux for transmission across a tool joint of a downhole drill string. The magnetic flux may be detected by another inductive coupler, magnetically coupled to the first inductive coupler, to convert the alternating magnetic flux back to an alternating current at the second frequency.

Abstract: Improved communication systems and methods are disclosed. In one embodiment, a downhole communications system comprises a downhole transceiver and a surface transceiver. The surface transceiver receives a discrete multi-tone (DMT) modulated uplink signal from the downhole transceiver, and transmits a downlink signal to the downhole transceiver using a modulation method determined by the transceivers as communications are initiated. The downlink modulation methods supported by the surface transceiver may include DMT modulation and quadrature amplitude modulation (QAM). The modulation mode selection may be based on measured channel characteristics, on proposed data rates, or on other predetermined parameters. The uplink and downlink signals may be communicated over a shared transmission mode on multiconductor cable or wired pipe, and alternatively the uplink and downlink signals may be communicated over separate transmission modes.

Abstract: A communication system for down hole use and comprising a drill collar (101) comprising a first portion (103) and a second portion (105) separated from each other by an electrically insulating material (67) and means (22, 63, 77, 81) for generating an electrical signal and for applying the electrical signal to the drill collar (101) such that the electrical signal is transmitted into a geological formation being drilled, characterized in that the means for generating the electrical signal comprises an alternator (22, 63, 77, 81) and means (2, 4, 10) responsive to an electrical output of the alternator for regulating rotation of the alternator.

Abstract: A transmission system between a voltage source and a wireline tool comprising a first loop to transmit a signal between the voltage source and the wireline tool. The first loop has a first transformer coupled to the voltage source. The system also comprises a second loop, electrically independent of the first loop, to transmit the signal between the voltage source and the wireline tool. The second loop has a second transformer coupled to the voltage source. If the first loop fails, the first transformer is isolated from the voltage source.

Abstract: A communication system for communication with a downhole tool comprising: a first communication transceiver in a first tool for measurement while drilling and a second communication transceiver in at least one of the first tool, a second tool for measurement while drilling, and an external instrumentation interface. The communication system also includes a bus system comprising a first conductive connection and a second conductive connection in each of the first tool and at least one of the first tool, a second tool and an external instrumentation interface, said first conductive connection and the second conductive connection of the first tool in operable communication with the first communication transceiver and the first conductive connection and the second conductive connection of the at least one of the first tool, a second tool and an external instrumentation interface also in operable communication with the second communication transceiver.

Abstract: Portable electronic apparatus is disclosed having a sensor for sensing the portable electronic apparatus coupled in intimate proximity to a rest. The rest may be a desk top, car instrument panel top or a special stand for the portable electronic apparatus. The portable electronic apparatus also has an inhibitor which inhibits operation of or locks the portable electronic apparatus, when the sensor senses absence of intimate proximity to the rest.

Abstract: A power supply apparatus is provided for supplying power and communications within a first piping structure. An external power transfer device is positioned around the first piping structure and is magnetically coupled to an internal power transfer device. The internal power transfer device is positioned around a second piping structure disposed within the first piping structure. A main surface current flowing on the first piping structure induces a first surface current within the external power transfer device. The first surface current causes a second surface current to be induced within the internal power transfer device.

Abstract: The invention includes a wireless communication circuit and a method of communicating with wireless signals that feature a tank circuit having an inductor connected in parallel with a capacitor circuit. The capacitor circuit includes a pair of capacitors coupled in series. Each of the capacitors is connected in common to ground and has a capacitive value associated. A feedback network is connected to selectively bias the tank circuit to produce a signal having an amplitude. The amplitude of the signal is a function of a ratio of the capacitive values associated with the capacitor circuit. The frequency of the signal is defined by the inductor and the capacitor circuit. The tank circuit is multifunctional in that it may be biased to function as a transmitter and a receiver.

Abstract: A power delivery system for a wireline tool includes two independent power transmission loops operating on a standard six-conductor cable. The two loops each connect directly to a respective terminals of a DC auxiliary power supply. Each loop also couples through a transformer to an AC instrument power supply. Another transformer for telemetry signals facilitates bidirectional communication between the downhole tool and an uphole computer.

Abstract: A petroleum well for producing petroleum products that incorporates a system adapted to provide power to a downhole device in the well. The system includes a current impedance device and a downhole power storage device. The current impedance device is positioned such that when a time-varying electrical current is transmitted through the portion of a piping structure and/or a voltage potential forms between one side of the current impedance device and another side of the current impedance device. The device is adapted to be electrically connected to the piping structure and/or across the voltage potential formed by the current impedance device, is adapted to be recharged by the electrical current, and is adapted to be electrically connected to the downhole device to provide power to the downhole device as needed.

Abstract: A data sonde for use in horizontal directional drilling comprising a battery housing to receive a power supply from an internal battery, a connector to receive a power supply from an external power supply cable, and an antenna to emit radiation, is provided, wherein the antenna is arranged to receive operative power from an external power supply when one is connected to the connector, and from a battery housed in the battery housing if no external power supply is connected to the connector. A method of operation of the same is also provided.

Abstract: A method is provided for monitoring a well. In a described embodiment, the method uses annulus pressure to communicate between a downhole system and a remote location. The method may use intermittent electrical power generated by changes in annulus pressure to power the downhole system. Various sensors and well tools may be monitored and actuated by the downhole system, and acquired data may be transmitted to the remote location.

Abstract: In order to provide an operation and maintenance planning aiding system for a power generation installation which prepares an operation plan for a plurality of power generation units by making use of actual plant data and based on a total judgement including a variety of circumstances of the machine and apparatus or the parts thereof in the power generation units, in the system the plurality of power generation units 41, 42, 51 and 52, a power supply command center 3 and a service center 1 are arranged and connected via a communication network 6, the service center 1 obtains the plant data via the communication network 6 from the plurality of power generation units 41, 42, 51 and 52, calculates in real time a power generation efficiency of a concerned power generation unit for every plurality of power generation units 41, 42 51 and 52 by making use of the obtained plant data and design data of the concerned power generation unit and prepares an operation and maintenance plan for each of the power generation u