Abstract: A modular multilevel power converter includes: a capacitor voltage adjuster that calculates an active current component command to make an average voltage of capacitors match a command value; an active power detector that receives an AC current signal and an AC voltage signal and calculates an active power; an active power adjuster that calculates a DC current command value to make the active power match a command value; a first active power command suppressor that suppresses an absolute value of an active power command value; and a second active power command suppressor that adjusts an absolute value of an active power command value.

Abstract: Providing a power system and a method for stabilizing a system, in which the number of generators to be disconnected is reduced to narrow an area influenced by a grid fault in the case where the reliability of the state estimation calculation is judged to be high.

Abstract: Providing a power system and a method for stabilizing a system, in which the number of generators to be disconnected is reduced to narrow an area influenced by a grid fault in the case where the reliability of the state estimation calculation is judged to be high.

Abstract: A two-shaft gas turbine having high operability is provided. The two-shaft gas turbine includes: a gas generator having a compressor, a combustor and a high pressure turbine; a power turbine having a low pressure turbine; a load connected to the power turbine; a motor/generator capable of rotatably driving the gas generator and capable of extracting power from the gas generator; electric equipment controlling the rotational driving and the power extraction by delivering electric power between the electric equipment and the motor/generator; and a control device controlling the electric equipment, wherein the combustor has a plurality of combustion regions to which a fuel is supplied through fuel adjustment means which are independent from each other, and the control device controls a delivery amount of the electric power delivered by the electric equipment corresponding to the number of combustion regions to which the fuel is supplied.

Abstract: The dual-shaft gas turbine power generation system includes: a high-pressure gas turbine; a first rotating shaft connecting a compressor and the high-pressure gas turbine; an electric motor connected to the first rotating shaft; a governor which adjusts the amount of air taken into the compressor; a low-pressure gas turbine; a second rotating shaft connected to the low-pressure gas turbine; a synchronous power generator connected to the second rotating shaft; a frequency converter which converts the frequency of power transmitted between the synchronous power generator and the electric motor; and a control device which controls a frequency converter control device for controlling the frequency converter, and the governor, on the basis of a power output command value indicating the power to be outputted to an external grid.

Abstract: The purpose is to provide a wind farm that is capable of increasing power generation output or a control method of a wind farm.

Abstract: A power converter with a simple configuration capable of controlling a rush current is provided. The power converter is installed between an electric power system and a power storage device, includes a harmonic filter in an AC circuit on the electric power system side and a DC capacitor and a DC breaker in a DC circuit on the power storage device side, and performs AC/DC conversion processing using an inverter. The power converter is configured in such a way that, when the power storage device starts running, a current limited by a limiting resistor is given from the electric power system side to the DC capacitor, the difference between the voltage of the DC capacitor and the voltage of the power storage device is monitored, and the power converter is connected to the power storage device by switching on the DC breaker on the basis of the difference.

Abstract: A rotary machine includes two sets of three-phase stator winding wires and two sets of inverters connected to the same direct-current power supply. Alternating-current terminals of the inverters are respectively connected to the three-phase stator winding wires. Stator winding wires are housed in a plurality of slots to form a stator. The two sets of three-phase stator winding wires and the stator winding wires in the same phase of the sets are started to be wound from the slot positions, with phases thereof being different from each other by 180 degrees, among the plurality of slots and are finished being wound in the slot positions, with phases thereof different from each other by 180 degrees. Winding end points of the three-phase stator winding wires are respectively connected in common, and alternating-current voltages having the same magnitude and opposite phases are applied to the two sets of three-phase stator winding wire.

Abstract: The dual-shaft gas turbine power generation system includes: a high-pressure gas turbine; a first rotating shaft connecting a compressor and the high-pressure gas turbine; an electric motor connected to the first rotating shaft; a governor which adjusts the amount of air taken into the compressor; a low-pressure gas turbine; a second rotating shaft connected to the low-pressure gas turbine; a synchronous power generator connected to the second rotating shaft; a frequency converter which converts the frequency of power transmitted between the synchronous power generator and the electric motor; and a control device which controls a frequency converter control device for controlling the frequency converter, and the governor, on the basis of a power output command value indicating the power to be outputted to an external grid.

Abstract: The dual-shaft gas turbine power generation system includes: a high-pressure gas turbine; a first rotating shaft connecting a compressor and the high-pressure gas turbine; an electric motor connected to the first rotating shaft; a governor which adjusts the amount of air taken into the compressor; a low-pressure gas turbine; a second rotating shaft connected to the low-pressure gas turbine; a synchronous power generator connected to the second rotating shaft; a frequency converter which converts the frequency of power transmitted between the synchronous power generator and the electric motor; and a control device which controls a frequency converter control device for controlling the frequency converter, and the governor, on the basis of a power output command value indicating the power to be outputted to an external grid.

Abstract: An electrical rotating machine system that can be easily maintained and can provide improved power generation efficiency. The electrical rotating machine system includes: a first electrical rotating machine having a first stator that has first stator windings, and a first rotor that has first rotor windings and is disposed on the internal diameter side of the first stator so as to have a gap between the internal diameter side of the first stator and the first rotor itself; a second electrical rotating machine having a second stator that has second stator windings, and a second rotor that has second rotor windings and is disposed on the internal diameter side of the second stator so as to have a gap between the internal diameter side of the second stator and the second rotor itself; and at least one power converter that is electrically connected to the first rotor windings and the second rotor windings, and configured to rotate when the first rotor rotates.

Abstract: A power conversion apparatus that is connected between a solar panel and a power system, in which the power conversion apparatus includes a power generating mode that converts a generated power of the solar panel into an alternating current power, and a snow melting mode that heats the solar panel by obtaining the power from the power system, and supplying the power to the solar panel, and at the time of the snow melting mode, the power conversion apparatus controls a voltage which is output to the solar panel such that a first current value being a value where a current that is supplied to the solar panel from the power conversion apparatus is smaller than an overcurrent level of the solar panel flows in a predetermined period.

Abstract: A power converter includes semiconductor switching elements conducting when the semiconductor switching elements fail; and open/close units that are disposed between parts having a plurality of different voltage levels and connection portions where the semiconductor switching units, which are to be connected to the parts having the different voltage levels, are connected to each other, and that open or close paths between the parts having the different voltage levels and the connection. When an excess current flows through any one of the open/close units, the one of the open/close unit opens the current path between the part having the corresponding voltage level and the connection portion. Then the power converter does not output the voltage to which the open/close unit is connected, and thereby the number of output voltage levels is reduced.

Abstract: A switching element of a power converter generates a low voltage, using a current flowing in the power converter, and supplies a power to drive itself. A switching element of a power converter for conversion from direct current into alternate current or from alternate current into direct current includes: a terminal and a terminal which are used in building the switching element itself in the power converter; a capacitor, a high-side controllable switch and a low-side controllable switch enabling outputting the voltage of the capacitor, the voltage being output between the terminal and the terminal, and a self-supply power source for supplying a power to drive the bi-directional chopper switching element itself, using a current flowing in the capacitor.

Abstract: A power converter with a simple configuration capable of controlling a rush current is provided. The power converter is installed between an electric power system and a power storage device, includes a harmonic filter in an AC circuit on the electric power system side and a DC capacitor and a DC breaker in a DC circuit on the power storage device side, and performs AC/DC conversion processing using an inverter. The power converter is configured in such a way that, when the power storage device starts running, a current limited by a limiting resistor is given from the electric power system side to the DC capacitor, the difference between the voltage of the DC capacitor and the voltage of the power storage device is monitored, and the power converter is connected to the power storage device by switching on the DC breaker on the basis of the difference.

Abstract: The dual-shaft gas turbine power generation system includes: a high-pressure gas turbine; a first rotating shaft connecting a compressor and the high-pressure gas turbine; an electric motor connected to the first rotating shaft; a governor which adjusts the amount of air taken into the compressor; a low-pressure gas turbine; a second rotating shaft connected to the low-pressure gas turbine; a synchronous power generator connected to the second rotating shaft; a frequency converter which converts the frequency of power transmitted between the synchronous power generator and the electric motor; and a control device which controls a frequency converter control device for controlling the frequency converter, and the governor, on the basis of a power output command value indicating the power to be outputted to an external grid.

Abstract: A two-shaft gas turbine having high operability is provided. The two-shaft gas turbine includes: a gas generator having a compressor, a combustor and a high pressure turbine; a power turbine having a low pressure turbine; a load connected to the power turbine; a motor/generator capable of rotatably driving the gas generator and capable of extracting power from the gas generator; electric equipment controlling the rotational driving and the power extraction by delivering electric power between the electric equipment and the motor/generator; and a control device controlling the electric equipment, wherein the combustor has a plurality of combustion regions to which a fuel is supplied through fuel adjustment means which are independent from each other, and the control device controls a delivery amount of the electric power delivered by the electric equipment corresponding to the number of combustion regions to which the fuel is supplied.

Abstract: A rotary machine includes two sets of three-phase stator winding wires and two sets of inverters connected to the same direct-current power supply. Alternating-current terminals of the inverters are respectively connected to the three-phase stator winding wires. Stator winding wires are housed in a plurality of slots to form a stator. The two sets of three-phase stator winding wires and the stator winding wires in the same phase of the sets are started to be wound from the slot positions, with phases thereof being different from each other by 180 degrees, among the plurality of slots and are finished being wound in the slot positions, with phases thereof different from each other by 180 degrees. Winding end points of the three-phase stator winding wires are respectively connected in common, and alternating-current voltages having the same magnitude and opposite phases are applied to the two sets of three-phase stator winding wire.

Abstract: An energy saving type feeder voltage compensation apparatus improved in availability at low temperatures, wherein when a electric energy storage apparatus is lower in temperature than a predetermined value, an output voltage output to a feeder side is made equal to or higher than a no-load output voltage of a substation connected in parallel. Power is supplied to a power running rolling stock preferentially from the electric energy storage apparatus. The heating value of the secondary battery is increased and the battery temperature is raised by this discharging, whereby internal resistance of the electric energy storage apparatus is lowered, and the charging and discharging loss is suppressed, and the efficiency and availability of the energy saving type feeder voltage compensation apparatus as a whole are improved.

Abstract: In a system to which a fluctuating load is connected, compensating for fluctuation in voltage harmonics at the load connecting point and fluctuation in system current harmonics has been difficult for a power converting device connected in parallel with the load. To resolve the problem, a power converting device connected in parallel with a fluctuating load includes: a Fourier series expansion unit which executes Fourier series expansion to load current by use of a reference sine wave in sync with a system and thereby outputs Fourier coefficients; and a fundamental component calculating unit which calculates a positive phase active fundamental component of the load current from the Fourier coefficients. A current instruction of the power converting device is generated by subtracting the fundamental current from the load current. With the current instruction, the fluctuations in system current harmonics and in voltage harmonics at the connecting point can be compensated for.