Abstract: A diagnostic apparatus for switching device diagnoses whether any anomalies occurs in a switching device including an operation shaft that opens and closes a circuit breaker contact serving as a contact. The diagnostic apparatus for switching device includes: a gradient calculation unit that calculates a gradient of a waveform that indicates motion of the operation shaft and represents a relationship between a position of the operation shaft and a time that elapses since an operating command has been input to the switching device; and an anomaly diagnosis unit that extracts, from a relationship between the time and the gradient calculated, a feature value representing a motion characteristic of the operation shaft and diagnoses whether an anomaly occurs and a factor behind the anomaly that occurs, on the basis of a result of comparison between the extracted feature value and a preset reference value.

Abstract: The voltage measuring device includes: a light source; a polarizer polarizing light emitted from the light source; a grounded conductor provided apart from a high-voltage conductor; a crystal end face electrode being out of contact with the grounded conductor and the high-voltage conductor; a Pockels cell transmitting light from the polarizer; an analyzer transmitting light reflected by the Pockels cell; a photodetector detecting light emitted from the analyzer; an intra-crystal electric field measurement unit converting voltage output by the photodetector into intra-crystal electric field; a bias electrode being out of contact with the crystal end face electrode; a bias supply; a bias supply control unit controlling the bias supply to keep internal electric field of the Pockels cell at zero; and a measurement voltage calculation unit obtaining voltage of the high-voltage conductor based on results output by the intra-crystal electric field measurement unit and the bias supply control unit.

Abstract: A diagnostic apparatus for switching device diagnoses whether any anomalies occurs in a switching device including an operation shaft that opens and closes a circuit breaker contact serving as a contact. The diagnostic apparatus for switching device includes: a gradient calculation unit that calculates a gradient of a waveform that indicates motion of the operation shaft and represents a relationship between a position of the operation shaft and a time that elapses since an operating command has been input to the switching device; and an anomaly diagnosis unit that extracts, from a relationship between the time and the gradient calculated, a feature value representing a motion characteristic of the operation shaft and diagnoses whether an anomaly occurs and a factor behind the anomaly that occurs, on the basis of a result of comparison between the extracted feature value and a preset reference value.

Abstract: The voltage measuring device includes: a light source; a polarizer polarizing light emitted from the light source; a grounded conductor provided apart from a high-voltage conductor; a crystal end face electrode being out of contact with the grounded conductor and the high-voltage conductor; a Pockels cell transmitting light from the polarizer; an analyzer transmitting light reflected by the Pockels cell; a photodetector detecting light emitted from the analyzer; an intra-crystal electric field measurement unit converting voltage output by the photodetector into intra-crystal electric field; a bias electrode being out of contact with the crystal end face electrode; a bias supply; a bias supply control unit controlling the bias supply to keep internal electric field of the Pockels cell at zero; and a measurement voltage calculation unit obtaining voltage of the high-voltage conductor based on results output by the intra-crystal electric field measurement unit and the bias supply control unit.

Abstract: An anomaly diagnosis device diagnoses anomaly of an oil-hydraulic operating mechanism that controls opening and closing of a circuit breaker. The anomaly diagnosis device includes: a first counter, which is a counter that counts the number of times of a pressure-increasing operation started upon a decrease in a hydraulic pressure maintained in the oil-hydraulic operating mechanism to a first reference pressure, and stopped upon an increase in the hydraulic pressure to a second reference pressure; a timer that measures an operation interval that is a time period from when a pressure-increasing operation is stopped until a next pressure-increasing operation is started; and an anomaly determiner that corrects, based on the operation interval, the number of pressure-increasing operations obtained based on a result of counting by the counter, and determines presence or absence of an anomaly in the oil-hydraulic operating mechanism using the corrected data of the number of pressure-increasing operations.

Abstract: An anomaly diagnosis device diagnoses anomaly of an oil-hydraulic operating mechanism that controls opening and closing of a circuit breaker. The anomaly diagnosis device includes: a first counter, which is a counter that counts the number of times of a pressure-increasing operation started upon a decrease in a hydraulic pressure maintained in the oil-hydraulic operating mechanism to a first reference pressure, and stopped upon an increase in the hydraulic pressure to a second reference pressure; a timer that measures an operation interval that is a time period from when a pressure-increasing operation is stopped until a next pressure-increasing operation is started; and an anomaly determiner that corrects, based on the operation interval, the number of pressure-increasing operations obtained based on a result of counting by the counter, and determines presence or absence of an anomaly in the oil-hydraulic operating mechanism using the corrected data of the number of pressure-increasing operations.

Abstract: In a voltage detection device for a transforming apparatus, a voltage divider is constituted by providing an intermediate electrode between a central conductor and a tank of the transforming apparatus, to detect a voltage E1 of the central conductor based on a voltage E2 of the voltage divider. The voltage detection device for a transforming apparatus includes an incomplete integration circuit having a reverse characteristic to an input/output voltage amplitude ratio-frequency characteristic of a high-pass filter formed by a floating electrostatic capacitance between the central conductor and the intermediate electrode, an earth electrostatic capacitance between the intermediate electrode and the tank, and a voltage dividing resistor connected in parallel to the earth electrostatic capacitance, and a signal processing circuit that outputs a value based on an output voltage E3 of the incomplete integration circuit as the voltage E1 of the central conductor.

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: 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: The current detection device includes a plurality of air-cored coils respectively attached to conductors for a plurality of phases, which are supported by an insulator and housed in a ferromagnetic tank a plurality of output-voltage detection circuits that detect output voltages of the air-cored coils for respective phases; and a correction processing circuit that obtains, by dividing the output voltages of the air-cored coils for respective phases by transformation ratios of the air-cored coils, current value levels, which are temporary values of currents flowing in the conductors for respective phases, calculates the output-voltage correction values for respective phases according to the current value levels of respective phases, and calculates and outputs current flowing in the conductors for respective phases on the basis of the output-voltage correction values.

Abstract: A voltage detection device is such that an intermediate electrode is provided between a central conductor to which a voltage is applied and a grounded tank to constitute a voltage divider and detects a voltage of the central conductor on the basis of a voltage of the voltage divider. The voltage detection device includes an integration circuit to which a voltage of the voltage divider, which is an output of the voltage divider, is input, an analog circuit that amplifies an output voltage of the integration circuit to a specified amplitude, an amplifier/attenuator to which a voltage of the voltage divider, which is an output of the voltage divider, is input and that amplifies or attenuates the voltage of the voltage divider to the specified amplitude, and an adder that adds an output voltage of the analog circuit and an output voltage of the amplifier/attenuator.

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.

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: A power switching control device and a closing control method thereof that can suppress generation of a transient voltage or current that is possibly caused by a variation in a load-side voltage after interrupting a current are obtained. A circuit-breaker-gap-voltage estimate value at and after a present time is calculated based on a power-supply-side voltage estimate value and a load-side voltage estimate value at and after the present time, a target closing-time domain from a closing controllable time to a closing control limit time in which a circuit breaker can be closed at a timing when an absolute value of the circuit-breaker-gap-voltage estimate value falls within a preset allowable range is calculated based on this circuit-breaker-gap-voltage estimate value, and the closing controllable time is delayed by a preset delay time in a case of a subsequent closing phase of a second or later closing phase.

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: A voltage detection device is such that an intermediate electrode is provided between a central conductor to which a voltage is applied and a grounded tank to constitute a voltage divider and detects a voltage of the central conductor on the basis of a voltage of the voltage divider. The voltage detection device includes an integration circuit to which a voltage of the voltage divider, which is an output of the voltage divider, is input, an analog circuit that amplifies an output voltage of the integration circuit to a specified amplitude, an amplifier/attenuator to which a voltage of the voltage divider, which is an output of the voltage divider, is input and that amplifies or attenuates the voltage of the voltage divider to the specified amplitude, and an adder that adds an output voltage of the analog circuit and an output voltage of the amplifier/attenuator.

Abstract: The current detection device includes a plurality of air-cored coils respectively attached to conductors for a plurality of phases, which are supported by an insulator and housed in a ferromagnetic tank a plurality of output-voltage detection circuits that detect output voltages of the air-cored coils for respective phases; and a correction processing circuit that obtains, by dividing the output voltages of the air-cored coils for respective phases by transformation ratios of the air-cored coils, current value levels, which are temporary values of currents flowing in the conductors for respective phases, calculates the output-voltage correction values for respective phases according to the current value levels of respective phases, and calculates and outputs current flowing in the conductors for respective phases on the basis of the output-voltage correction values.

Abstract: In a voltage detection device for a transforming apparatus, a voltage divider is constituted by providing an intermediate electrode between a central conductor and a tank of the transforming apparatus, to detect a voltage E1 of the central conductor based on a voltage E2 of the voltage divider. The voltage detection device for a transforming apparatus includes an incomplete integration circuit having a reverse characteristic to an input/output voltage amplitude ratio-frequency characteristic of a high-pass filter formed by a floating electrostatic capacitance between the central conductor and the intermediate electrode, an earth electrostatic capacitance between the intermediate electrode and the tank, and a voltage dividing resistor connected in parallel to the earth electrostatic capacitance, and a signal processing circuit that outputs a value based on an output voltage E3 of the incomplete integration circuit as the voltage E1 of the central conductor.

Abstract: A power switching control device and a closing control method thereof that can suppress generation of a transient voltage or current that is possibly caused by a variation in a load-side voltage after interrupting a current are obtained. A circuit-breaker-gap-voltage estimate value at and after a present time is calculated based on a power-supply-side voltage estimate value and a load-side voltage estimate value at and after the present time, a target closing-time domain from a closing controllable time to a closing control limit time in which a circuit breaker can be closed at a timing when an absolute value of the circuit-breaker-gap-voltage estimate value falls within a preset allowable range is calculated based on this circuit-breaker-gap-voltage estimate value, and the closing controllable time is delayed by a preset delay time in a case of a subsequent closing phase of a second or later closing phase.