Mitsubishi Electric Corporation

Agc Inc.

Aya Yamamoto

Daisuke Yoshida

Hiroki Ito

Tomohito Mori

Yusuke Kobayashi

Kenji Kamei

Kenji Inomata

Sho Tokoyoda

Daigo Matsumoto

Shuichi Tanigaki

Hiroyuki Tsutada

Haruhiko Koyama

Shoichi Kobayashi

Yoshitaka Saijo

Takashi Shindoi

A transparent substrate having an antiglare function includes first and second faces. The transparent substrate has a resolution index value T, a reflected image diffusivity index value R, and a sparkle index value S satisfying T&#x2265;0.25, R&#x2265;0.8, and 0.75&#x2264;S&#x2264;0.95, respectively. The resolution index value T is calculated as (luminance of zero-degrees transmission light)/(luminance of total transmission light). The reflected image diffusivity index value R is calculated as (R+R)/(2&#xd7;R), where Rdenotes a luminance of reflected light reflected at first angle &#x3b1;, and R, Rdenote luminance of reflected light at the second angle &#x3b1;, the third angle &#x3b1;, respectively, with respect to the first angle &#x3b1;. The sparkle index value S is calculated as 1&#x2212;(S/S), where the first sparkle Sand the second sparkle Sdenote a sparkle value of the transparent substrate and a sparkle value of a glass substrate, respectively.

Transparent substrate

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

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.

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

An inrush-current suppressing device includes a residual-magnetic-flux calculation unit that obtains a residual magnetic flux generated within a three-phase transformer, an input magnetic-flux-error calculation unit that obtains a closing-phase input magnetic-flux error, a closing-order determination unit that determines a closing order of phases of a three-phase breaker, a target-closing-phase/time setting unit that sets a time from a reference point to a target closing phase of a first closing phase as a first target closing time, and sets a time obtained by adding up a time from the reference point to a target closing phase of a second closing phase and a delay time set to exclude a period in which a magnetic flux in the first closing phase possibly saturates as a second target closing time, and a closing control unit that generates and outputs a closing control signal to close each phase at the target closing time.

Growing community of inventors

Tokyo, Japan

Aya Yamamoto