Abstract: A power switching control device includes a voltage measurement unit to measure a power-source-side voltage of a circuit breaker and a load-side voltage of the circuit breaker, an inter-pole-voltage estimation unit to estimate a future inter-pole voltage from a value of the power-source-side voltage and a value of the load-side voltage, a target closing-clock-time determination unit to set a target activation point of the circuit breaker on a waveform of an absolute value of the future inter-pole voltage, set an inter-pole withstand-voltage characteristic line calculated from a rate of decrease of dielectric strength, so that the inter-pole withstand-voltage characteristic line passes through the target activation point, and determine a clock time when the inter-pole withstand-voltage characteristic line becomes zero as a target closing clock time of the circuit breaker, and a closing control unit to close the circuit breaker at the target closing clock time.

Abstract: A power switching control device includes a unit to measure a power-supply-side voltage of a circuit breaker, a unit to calculate a current that flows through a resistor after a switch is turned on and before a circuit breaking unit is turned on, and to calculate an interelectrode voltage of the circuit breaking unit after the switch is turned on and before the circuit breaking unit is turned on, a unit to determine a target closing time point for the circuit breaking unit so that a target turn-on phase for the circuit breaking unit becomes a phase that is set in accordance with the capacitor, and to output a control signal such that the circuit breaking unit is closed at the target closing time point.

Abstract: The present invention provides a phase control device applied to a three-phase circuit including a three-phase transformer and a three-phase breaker that turns on/off the transformer. The device suppresses an excitation rush current generated in the transformer. The device includes a controller that closes any one phase of the breaker as a closing first phase and subsequently closes the other phases, a determiner that determines the closing first phase based on residual magnetic fluxes of the respective phases in the transformer, a determiner that determines, based on a pre-arc characteristic and a closing time variation characteristic of the breaker, target closing phases and target closing times of the closing first phase and the other phases, a calculator that calculates a closing time of each phase of the breaker, and an operation time table that stores, as a median of the variation characteristic represented by a normal distribution, the calculated time.

Abstract: An operating device for a power switchgear includes: an output lever coupled to a movable-contact of the switchgear; a torsion bar releasing an accumulated force when the switchgear is opened to rotate the lever in the counterclockwise direction and drive the movable-contact in an opening direction; an opening latch engaged with the lever to hold an accumulated force of the torsion bar; a cam rotating when the switchgear is closed, having contact with the lever to rotate the lever in the clockwise direction, and driving the movable-contact in a closing direction; another torsion bar releasing the accumulated force when the switchgear is closed to rotate the cam; and a closing latch which can be engaged with the cam to hold the accumulated force of the torsion bar. The cam includes opposed cam elements, a pin whose ends are rotatably supported by the elements, and a bolt fastening the elements.

Abstract: A circuit breaker characteristic monitoring device monitors the operation of a circuit breaker to estimate the amount of consumption of a movable contact and fixed contacts included in the circuit breaker. The device includes an operating time measurement unit to measure at least one of closing time, which is the time required for the circuit breaker to be closed after starting a closing operation, and opening time, which is the time required for the circuit breaker to be open after starting an opening operation, and a contact consumption amount estimation unit to estimate the amount of consumption of the movable contact and the fixed contacts on the basis of the result of measurement performed by the operating time measurement unit and travel speed of the movable contact during the closing operation or the opening operation for which the measurement result is obtained.

Abstract: An operating device includes: a movable core reciprocally movable along an operational axis; a stationary core provided along the operational axis and facing the movable core; a first coil configured from a first wire wound in a cylindrical shape centered about the operational axis; and a second coil configured from a second wire wound around an outer side of the first coil in a cylindrical shape centered about the operational axis. The second wire has a larger wire diameter than the first wire.

Abstract: A power switching control apparatus includes a current measurement unit that measures the current of a main circuit; a current estimation unit that detects a fault current on the basis of a current measurement value and estimates a future current waveform on the basis of a current waveform measured in a given duration after the detection; a target opening time determination unit that uses a current zero point obtained from the estimated current waveform, a predicted opening time, and a given minimum arc duration so as to determine a time by subtracting a sum of the opening time and the minimum arc duration from the current zero point as the target opening time; and an opening control unit that waits until the nearest one of the target opening times is reached and transmits an interruption control signal when the target opening time is reached.

Abstract: A power switching control device includes a unit to measure a power-supply-side voltage of a circuit breaker, a unit to calculate a current that flows through a resistor after a switch is turned on and before a circuit breaking unit is turned on, and to calculate an interelectrode voltage of the circuit breaking unit after the switch is turned on and before the circuit breaking unit is turned on, a unit to determine a target closing time point for the circuit breaking unit so that a target turn-on phase for the circuit breaking unit becomes a phase that is set in accordance with the capacitor, and to output a control signal such that the circuit breaking unit is closed at the target closing time point.

Abstract: A phase control device includes a connection error detection unit. The connection error detection unit includes a phase sequence detection unit that detects a phase sequence of voltage signals, a phase sequence detection unit that detects a phase sequence of current signals, a collation unit that collates the phase sequence of the voltage signals and the phase sequence of the current signals and determines that a connection error is present when the phase sequences are different, phase difference detection units that detect a phase difference between the voltage signal and the current signal, and a phase difference determination unit that determines, when the phase differences output from the phase difference detection units fall without a determination range, that a connection error is present.

Abstract: An operating device for a power switchgear includes: an output lever coupled to a movable-contact of the switchgear; a torsion bar releasing an accumulated force when the switchgear is opened to rotate the lever in the counterclockwise direction and drive the movable-contact in an opening direction; an opening latch engaged with the lever to hold an accumulated force of the torsion bar; a cam rotating when the switchgear is closed, having contact with the lever to rotate the lever in the clockwise direction, and driving the movable-contact in a closing direction; another torsion bar releasing the accumulated force when the switchgear is closed to rotate the cam; and a closing latch which can be engaged with the cam to hold the accumulated force of the torsion bar. The cam includes opposed cam elements, a pin whose ends are rotatably supported by the elements, and a bolt fastening the elements.

Abstract: An apparatus for predicting an operating time in a power device includes an operating characteristic parameter estimating unit, and only the operation historical data in the vicinity of a current operation environmental condition is extracted and input by a vicinity operation historical data extracting unit.

Abstract: A power switching control device includes a voltage measurement unit to measure a power-source-side voltage of a circuit breaker and a load-side voltage of the circuit breaker, an inter-pole-voltage estimation unit to estimate a future inter-pole voltage from a value of the power-source-side voltage and a value of the load-side voltage, a target closing-clock-time determination unit to set a target activation point of the circuit breaker on a waveform of an absolute value of the future inter-pole voltage, set an inter-pole withstand-voltage characteristic line calculated from a rate of decrease of dielectric strength, so that the inter-pole withstand-voltage characteristic line passes through the target activation point, and determine a clock time when the inter-pole withstand-voltage characteristic line becomes zero as a target closing clock time of the circuit breaker, and a closing control unit to close the circuit breaker at the target closing clock time.

Abstract: The present invention provides a phase control device applied to a three-phase circuit including a three-phase transformer and a three-phase breaker that turns on/off the transformer. The device suppresses an excitation rush current generated in the transformer. The device includes a controller that closes any one phase of the breaker as a closing first phase and subsequently closes the other phases, a determiner that determines the closing first phase based on residual magnetic fluxes of the respective phases in the transformer, a determiner that determines, based on a pre-arc characteristic and a closing time variation characteristic of the breaker, target closing phases and target closing times of the closing first phase and the other phases, a calculator that calculates a closing time of each phase of the breaker, and an operation time table that stores, as a median of the variation characteristic represented by a normal distribution, the calculated time.

Abstract: A circuit breaker characteristic monitoring device monitors the operation of a circuit breaker to estimate the amount of consumption of a movable contact and fixed contacts included in the circuit breaker. The device includes an operating time measurement unit to measure at least one of closing time, which is the time required for the circuit breaker to be closed after starting a closing operation, and opening time, which is the time required for the circuit breaker to be open after starting an opening operation, and a contact consumption amount estimation unit to estimate the amount of consumption of the movable contact and the fixed contacts on the basis of the result of measurement performed by the operating time measurement unit and travel speed of the movable contact during the closing operation or the opening operation for which the measurement result is obtained.

Abstract: A target pole-close timing determining unit corrects a breaker characteristic correction signal of a preceding turn-on phase by using a correction amount which is proportional to an absolute value of the interpolar voltage upon turn-on of the proceeding turn-on phase, and a correction amount which is proportional to an elapsed time after a target pole-close timing of the preceding turn-on phase, to generate a subsequent phase interpolar voltage signal, and determines a target pole-close timing of the subsequent turn-on phase at a timing when the subsequent phase interpolar voltage signal is equal to or smaller than a threshold value.

Abstract: To provide a cam clutch including an outer ring, an inner ring provided inside of the outer ring, a plurality of cams inserted between the outer ring and the inner ring, and an annular spring. A line connecting a first abutment portion between the outer ring and each of the cams and a second abutment portion between the inner ring and the cam and a line passing the second abutment portion form an angle in a state with the cams engaging with the outer ring and the inner ring. Rotation of the outer ring and the inner ring is enabled in the respective one directions while rotation thereof is restricted in the respective other directions. A groove is formed on an inner periphery of the outer ring or an outer periphery of the inner ring.

Abstract: A pressure vessel includes a main pipe and branch pipes branching off from the side surface of the main pipe. Reinforcing ribs are provided as reinforcing members on the side surfaces of the branch pipes. Among the reinforcing members, the reinforcing rib has a structure continuously extended between the branch pipes to relieve the concentrations of stress that occur at the bases of the branch pipes.

Abstract: A power switching control apparatus includes a current measurement unit that measures the current of a main circuit; a current estimation unit that detects a fault current on the basis of a current measurement value and estimates a future current waveform on the basis of a current waveform measured in a given duration after the detection; a target opening time determination unit that uses a current zero point obtained from the estimated current waveform, a predicted opening time, and a given minimum arc duration so as to determine a time by subtracting a sum of the opening time and the minimum arc duration from the current zero point as the target opening time; and an opening control unit that waits until the nearest one of the target opening times is reached and transmits an interruption control signal when the target opening time is reached.

Abstract: A spring operation device for use in a switchgear includes an interlock bar, attached at its one end to a lock plate and includes a switch-on electromagnet that has a plunger provided with a flange portion. The lock plate is pushed by a lock member that is attached to a four-joint link and the position of the lock plate is changed by being rotated. During an opening operation of a switching contact, the other end of the interlock bar is arranged above the flange portion to stop the forward movement of the plunger of the switch-on electromagnet so as to prevent a switch-on trigger from rotating. During a closing operation of the switching contact, the other end of the interlock bar is arranged at a position that does not stop the plunger of the switch-on electromagnet from moving forward so that the switch-on trigger is allowed to rotate.

Abstract: A power switching control apparatus includes a voltage measurement unit that measures a power-source side voltage and a transmission-line side voltage of a circuit breaker, a voltage estimation unit that estimates a power-source side voltage estimate value and a transmission-line side voltage estimate value according to measurement values, and a target closing time calculation unit that calculates a target closing time according to the estimate values. The target closing time calculation unit calculates an interpolar voltage estimate value by using both the power-source side and the transmission-line side voltage estimate value, calculates an electric turn-on time range, which is the maximum variation range of an electric turn-on time of the circuit breaker, calculates a maximum value of interpolar voltage, and determines that a time at which the maximum value of the interpolar voltage is not more than a threshold and achieves the local minimum value be a target closing time.