Abstract: An electrical power supply system includes an electrical power source system connected to a bus bar and a plurality of electric power transmission systems each connected via circuit breakers to the bus bar. The supply system has overvoltage suppression equipments each installed between the transmission system and the ground. The overvoltage suppression equipment includes a switching device and an impedance connected to the switching device. The switching device in a sound transmission system is closed when the circuit breaker operates in other faulty transmission system, thereby an overvoltage being occurred on the sound system is effectively suppressed.

Abstract: A three-phase collected type optical current transformer having a common hermetically sealed container miniaturized in its radial direction. The common hermetically sealed container incorporating central conductors and optical current transformers corresponding to three phases has a branch tube or flange in its radial direction. The flange incorporates optical spacial transmission members for three phases which guide the signals sent from the optical current transformers through optical fibers to the exterior of the common hermetically container. The optical spatial transmission members are arranged collectively. The common hermetically sealed container, when it has a branching portion protruding in its radial direction at its end, incorporates no flange but a concentrated optical spacial transmission member for three phases at the end in the axial direction of the common hermetically sealed container having the branching member.

Abstract: An electrical power system protection device includes a circuit breaker and a switch connected in series to a power line. The protection device also has a current limiting element connected in parallel to the circuit breaker. When the level of electrical current flowing in the power line, detected by a current detector, has exceeded a predetermined first set level, a first over-current detector delivers immediately a trip command to the circuit breaker. As a consequence, fault current is commutated to the current limiting element so that any drop of voltage in the power line upstream of the circuit breaker is greatly suppressed. When a state in which a predetermined second set level is exceeded by the detected current level is continued beyond a predetermined period, a second over-current detector delivers an off command to the switch, thus protecting the upstream portion of the power line against the fault in this power line.

Abstract: A gas blast circuit breaker comprises an insulation nozzle for blowing extinguishing gas to an arc generated between a stationary contact and a movable contact. The nozzle has a throat section into and out of which one of the two contacts is movable and a divergent section provided downstream of the throat section. A slanting surface for increasing a reflectivity of energy intensity of the arc is formed on the divergent section of the nozzle. The nozzle is formed of a fluoroplastic material and boron nitride powder of not more than 15 vol. % is added as a filler.

Abstract: A power apparatus has a network formed by a plurality of interconnected components being, e.g., one or more high voltage conductors in a casing of a metal filled with an insulating gas. Detectors are provided which detect electromagnetic waves, which are generated if there is a fault. The electromagnetic waves are analyzed to detect the location of the fault. The analysis may make use of attenuation coefficients corresponding to each component of the network to extrapolate between detectors on either side of the fault and/or to compare with predetermined wave strengths. A map of the network may be stored in a suitable memory to assist in the calculation of the fault location, and the memory may also store the attenuation coefficients themselves. The location of the fault may then be displayed by a suitable display, to give the time variation of the fault.

Abstract: A power appliance diagnosis apparatus includes a plurality of detectors provided on outer surfaces of gas-insulated casings of a power appliance for detecting the state of an insulating function and/or a current conduction function of the power appliance, a switch for time-divisionally taking in detection signals of the plurality of detectors, a frequency analyzer for performing frequency analysis on the detection signals taken in by the switch, and a controller for performing switching control of the switch.

Abstract: A puffer type gas-insulated circuit breaker is adapted to, when its movable electrode separates from a stationary electrode, enable an insulating gas blow toward an occurring arc to extinguish the same. An insulated nozzle is provided to direct the gas toward the arc and forms a gas passage in cooperation with an insulating cover which covers the movable electrode. The insulated cover is formed of an insulating material which contains a filler for preventing energy lines of the arc from entering the cover. Furthermore, the insulated cover has a specific inductive capacity greater than a specific inductive capacity of the insulated nozzle so as to reduce the electric field strength at the front end of the movable electrode.

Abstract: An abnormality diagnosing system and method for high voltage power apparatus wherein a plurality of detectors for detecting abnormalities of the high voltage power apparatus and providing outputs indicative thereof are disposed to detect predetermined phenomena indicative of at least an insulation abnormality, power supply abnormality, and foreign matter among abnormalities existing inside of the high voltage power apparatus. A monitoring arrangement responsive to the outputs of the detectors provides at least one of an output and display of the kind of abnormality detected.

Abstract: A power apparatus in which a particle in an enclosure of the apparatus containing an electric conductor therein is moved in the enclosure by an electric field so as to cause an abnormality of insulation. The apparatus includes a first sensor for detecting an existence position of the particle on the basis of a sound of collision of the particle against the enclosure, a second sensor for detecting a partial discharge generated in the enclosure, and a device for receiving respective detection signals from the first and second sensors, for judging the existence of insulation abnormality caused by the particle inside the enclosure, and for outputting a result of the judgment.

Abstract: An abnormality diagnosing system and method for high voltage power apparatus wherein a plurality of detectors for detecting abnormalities of the high voltage power apparatus and providing outputs indicative thereof are disposed to detect predetermined phenomena indicative of at least an insulation abnormality, power supply abnormality and foregin matter among abnormalities existing inside of the high voltage power apparatus. A monitoring arrangement responsive to the outputs of the detectors provides at least one of an output and display of the kind of abnormality detected.

Abstract: A contact abnormality detection system for use in a gas-insulated switchgear or other power transmission or distribution apparatus. A gas-insulated switchgear includes a hermetic housing, an insulating gas sealed in the housing, and conductors in the housing having contacts for providing a path for a large current and being electrically insulated from the housing. An abnormality in the contacts causes the contacts to generate vibrations when a large current flows through them. A vibration detector detects vibrations generated by the switchgear including the vibrations generated by the contacts. The frequency spectrum of the vibrations detected by the vibration detector is analyzed to detect if the vibrations contain frequency components in the range of 200 to 500 Hz which meet predetermined criteria.

Abstract: In an insulation testing device for testing insulation characteristics of a gas insulated apparatus, at least one pair of positive and negative polarity impulse voltages each having a duration shorter than a half period of a commercial frequency voltage are applied to the gas insulated apparatus by a test voltage generator.

Abstract: An insulating spacer for use in a gas-insulated electric apparatus for supporting a high-tension electric conductor inserted through a metallic pipe enclosing an insulating gas, in which the insulating spacer is provided with a plurality of fins on its creeping surface, and in which fin intervals between the metallic pipe and one of the fins adjacent to the metallic pipe, between adjacent ones of the fins, and between the high-tension electric conductor and one of the fins adjacent to the high-tension electric conductor are formed in a manner so that the fin interval formed at a position where a creeping component electric field is high is made narrower than the fin interval formed at a position where a creeping component electric field is lower than that in the first-mentioned position.

Abstract: The invention relates to a conductor supporting apparatus for gas insulated equipment in which a high voltage conductor which is arranged in a grounded tank is insulated and supported by an insulating spacer having attaching metal fittings at both end portios. In the apparatus of the invention, a cylindrical insulating barrier having a flange portion on the side of the free end so as to be substantially perpendicular to the surface of the insulating spacer is attached by use of the attaching metal fitting of the insulating spacer on at least the side of the grounded tank. The insulating spacer is surrounded by this insulating barrier through a space. By use of the insulating barrier, the approach of conductive foreign matters to the insulating spacer can be prevented and the high dielectric strength can be maintained.

Abstract: A gas insulated electrical apparatus comprises: a metal pipe in which an insulation gas is sealed; a conductor supported inside of the metal pipe by an insulation supporting member; and an insulation layer provided on the inner surface of the metal pipe. Strong dielectric material is mixed in the insulation layer so that its specific inductive capacity becomes ten or more.

Abstract: An electret capable of holding electric charges semi-permanently is used to attract conductive particles generated or intruded in a gas-insulated electric apparatus during assembly work including an operation test of movable parts thereof, thus improving the reliability of insulation characteristic of the apparatus.

Abstract: There is disclosed a method of testing and verifying a performance for insulation to ground of a disconnecting switch when breaking a charging current. This disconnecting switch has a movable electrode and a fixed electrode which are arranged in a tank so as to face each other. One of these electrodes is connected to an electrostatic capacity load and the other is connected to a power supply. This test method comprises the steps of: applying a voltage from the power supply through the disconnecting switch to the load to cause the voltage to be trapped in the load; and applying a voltage of the polarity opposite to that of the trapped charged voltage from the power supply to the disconnecting switch to cause the discharge between those electrodes, thereby verifying the performance for insulation to ground.

Abstract: A ceramic capacitor comprises a column-like ceramic element having end faces provided with electrodes, respectively. A disk-like reinforcing element is secured to at least one of the electrodes in close contact therewith. The thickness T and diameter D of the ceramic element are selected so that T/D.ltoreq.0.5 and D.sub.t /D.gtoreq.0.6 where D.sub.t represents the thickness of the reinforcing metal member. The dielectric breakdown field strength appearing upon application of a chopped-wave impulse voltage can be increased at least to the dielectric breakdown field strength appearing upon application of a full-wave impulse voltage.