Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Tomohito Mori

Kenji Kamei

Sadayuki Kinoshita

Aya Yamamoto

Haruhiko Koyama

Daisuke Yoshida

Shuichi Tanigaki

Hiroki Ito

Daigo Matsumoto

Hiroyuki Tsutada

Shoichi Kobayashi

Kenji Inomata

Masahiro Shikai

Sho Tokoyoda

Kyoichi Otsuka

Kyoichi Ohtsuka

Nobuya Nakajima

Takashi Shindoi

Seiki Ishitani

Yves Corrodi

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.

Power switching control device

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.

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.

Phase control device

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.

Operating device for power switchgear

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.

Circuit breaker characteristic monitoring device

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.

Power switching control apparatus and switching control method therefor

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.

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.

Power switching device operating time prediction equipment and method

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.

Power switching control apparatus for switching timings of breaker to suppress transit voltage and current upon turning on the breaker

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.

Cam clutch

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.

Spring operation device for switchgear

A circuit breaker includes: a first arc-extinguishing chamber and a second arc-extinguishing chamber that interrupt a current by opening contact points and extinguish an arc during the current is being interrupted; and a connection unit that connects the first arc-extinguishing chamber and the second arc-extinguishing chamber to each other. The first arc-extinguishing chamber and the second arc-extinguishing chamber are connected to the connection unit in such a manner that shaft lines of the arc-extinguishing chambers form an angle of substantially 90 degrees. The first arc-extinguishing chamber is arranged on a side of the connection unit in such a manner that the shaft line thereof is substantially horizontal, and the second arc-extinguishing chamber is arranged on an upper side of the connection unit in such a manner that the shaft line thereof is substantially vertical.

Circuit breaker

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.

Power switching control device and closing control method thereof

An inrush current suppressing device includes a residual-magnetic-flux calculating unit configured to retain an interruption characteristic of a breaker and an attenuation characteristic of a magnetic flux that are estimated by measurement, analysis, or the like beforehand, and apply the attenuation characteristic to a magnetic flux value at the time of current interruption obtained based on the interruption characteristic of the breaker to calculate a residual magnetic flux value. The breaker is turned on in a power supply voltage phase in which the calculated residual magnetic flux value and a theoretical value of a steady magnetic flux match.

Inrush current suppressing device

An inrush-current suppressing device includes: a residual-magnetic-flux calculating unit that calculates a residual magnetic flux in a reference phase of a three-phase transformer while assuming a maximum magnetic flux level generated at a time of applying a rated voltage as 1 PU based on a measurement result of a transformer-voltage measuring unit before and after opening a three-phase circuit breaker; a stationary-magnetic-flux calculating unit that calculates a stationary magnetic flux in the reference phase of the three-phase transformer with reference to the maximum magnetic flux level obtained as the 1 PU based on a measurement result of a power-supply-voltage measuring unit, in response to a closing command to the three-phase circuit breaker; and a control unit that actuates a switch of the three-phase circuit breaker corresponding to the reference phase at a timing when the stationary magnetic flux and the residual magnetic flux in the reference phase match each other.

Growing community of inventors

Tokyo, Japan

Tomohito Mori