Abstract: The present invention provides a power-system stabilization system and a power-system stabilization method, which fundamentally solve the problems of insufficiency and fluctuation in the voltage maintenance capacity and the frequency maintenance capacity. A power-system stabilization system of the present invention comprises a synchronous machine to be field-regulated disposed in an electric power station connected to a power system, a magnetic field regulator for controlling the synchronous machine, and a compensation circuit for correcting a control constant of the magnetic field regulator in accordance with a power-system stability maintaining index that is an index reflecting a renewable energy amount in the power system.

Abstract: The present invention provides a magnetic field control device and a magnetic field control method for a synchronous machine, which can fundamentally cope with the problem of the lack and fluctuation in the voltage maintaining ability from a point of view of a power generation of a power system. A magnetic field control device of the present invention is a device for a synchronous machine that controls a magnetic field of the synchronous machine connected to a power system. The magnetic field control device comprises a magnetic field control system operating electric current flowing through a magnetic field coil of the synchronous machine; a regulator of the magnetic field control system; and a compensation circuit variably regulating a control constant of the magnetic field control system according to a magnitude of magnetic field current or an equivalent of the magnetic field current.

Abstract: A water level control system for enhancing the controllability of the level of water retained in a steam drum. A water level control section of the system determines the volume of retained water in a steam-water separator from a detected steam flow rate signal by using a function operator and a first order lag circuit, determines a signal representing the mass flow rate balance of water in the steam-water separator by differentiating the volume of retained water with respect to time with a differentiator, generates a compensated signal by adding the signal to the difference between a detected feed water flow rate signal and the detected steam flow rate signal, and properly compensates a valve area demand for a feed water flow control valve.

Abstract: To achieve a fluid level measurement instrument requiring no detecting pipe that can accurately measure over a long period of time a fluid level in a tank for storing therein fluid without having to use a detecting pipe for sampling the fluid from the tank. A balance tube 41 has no detecting pipes and a solenoid coil 45 is wound around an outside of the balance tube 41. A float 46 containing therein a magnetic material 47 is disposed inside the solenoid coil 45. A cover 59 formed, for example, of metal covers an outer surface of the float 46 to prevent entry of fluid and hydrogen from outside. The float 46 moves according to a fluid level in the balance tube 41, which results also in inductance of the solenoid coil 45 being changed. Measuring the inductance of the solenoid coil 45 allows the fluid level of the balance tube 41 to be measured without having to use the detecting pipe.

Abstract: A water level control system for enhancing the controllability of the level of water retained in a steam drum. A water level control section of the system determines the volume of retained water in a steam-water separator from a detected steam flow rate signal by using a function operator and a first order lag circuit, determines a signal representing the mass flow rate balance of water in the steam-water separator by differentiating the volume of retained water with respect to time with a differentiator, generates a compensated signal by adding the signal to the difference between a detected feed water flow rate signal and the detected steam flow rate signal, and properly compensates a valve area demand for a feed water flow control valve.

Abstract: In a bushing which has a terminal with a bend for connecting a conduit tube and a lead tube, the effect to cool the inner corner of the bend is enhanced. The bushing includes a conductive conduit tube, a conductive lead tube, and a terminal. The terminal has a bend and connects the conduit tube and the lead tube. Electric current and cooling gas flows in these tubes. A cooling means is provided for forced cooling of the inner corner of the bend of the terminal. One example of the cooling means is a guide vane which makes cooling gas flowing in the bushing come closer to the inner corner of the bend. A larger current can flow even when the bushing has the same size as a conventional one.