Abstract: A storage battery management device according to one embodiment includes a hardware processor that causes a display device to display first remaining life information and second remaining life information. The first remaining life information indicates current remaining life of a storage battery system. The first remaining life information is calculated on the basis of a state of health (SOH) of each of multiple storage battery modules constituting the storage battery system. The second remaining life information indicates remaining life of the storage battery system and corresponds to a case where one or more of the multiple storage battery modules are replaced with one or more other storage battery modules. The second remaining life information is calculated on the basis of an SOH of each storage battery module not being replaced and an SOH of each of the one or more other storage battery modules.

Abstract: A storage battery management device includes an acquisition unit, a selection unit, an estimation unit, and a display control unit. The acquisition unit acquires a battery characteristic and an operation condition of a storage battery device. The selection unit selects data values from a data value group of a data item in which variation in data value is caused out of data items included in the battery characteristic and the acquired operation condition. The estimation unit estimates, for each of the selected data values, a battery characteristic after operation corresponding to a case where the storage battery device is operated under the operation condition. The battery characteristic is estimated on the basis of the battery characteristic and the operation condition acquired by the acquisition unit. The display control unit displays the battery characteristic estimated by the estimation unit in a comparable state.

Abstract: A storage battery management device according to one embodiment includes a hardware processor functioning as an acquisition unit, a calculation unit, and a display control unit. The acquisition unit acquires, as current operation state data of a storage battery system including a plurality of storage batteries, charge/discharge power, a cell voltage, a charge/discharge current, and a temperature of a battery board of the storage battery system. The calculation unit calculates, by using a digital model for simulating operation of the storage battery system, a chargeable/dischargeable capacity, a State of Charge (SOC) level change amount, and an SOC maintainable charge/discharge amount being a charge/discharge amount maintaining an SOC level within a predetermined range. The display control unit causes a display unit to display the chargeable/dischargeable capacity, the SOC level change amount, and the SOC maintainable charge/discharge amount.

Abstract: A storage battery control device includes a hardware processor functioning as an acquisition unit, a first calculation unit, and a control part. The acquisition unit acquires operation conditions of a storage battery system including a storage battery being chargeable and dischargeable. The first calculation unit calculates, as a first predicted value, a battery capacity of the storage battery in a predetermined period on the basis of the operation conditions acquired by the acquisition unit. The battery capacity corresponds to a case where the storage battery is operated under the operation conditions. The control part controls a charging voltage when the storage battery system charges the storage battery. The charging voltage is controlled on the basis of the first predicted value calculated by the first calculation unit.

Abstract: Provide is a power conversion device capable of avoiding a power outage even if reference AC power is lost. A power conversion device 1 includes a phase detector 31 calculating a voltage phase based on the phase of AC power supplied to an electric power system 9, a waveform controller 35 generating a control signal designating the frequency and phase of the AC power based on the voltage phase calculated by the phase detector 31, a power conversion circuitry 12 which converts power supplied from a power supply source 15 into the AC power based on the control signal generated by the waveform controller 35, and which outputs the converted power to the electric power system 9, and a determination block 44 which detects the frequency of the AC power supplied to the electric power system 9, and which determines that the AC power that becomes the reference for the frequency is not supplied to the electric power system 9 when the detected frequency is not within a preset first frequency range.

Abstract: Provided is a power converter capable of reducing cross current. The power converter 1 includes a phase controller 20 that calculate a phase angle reference value ?m based on a difference between a commanded active power reference value Pe and an output active power P supplied to a distribution line 5, a voltage controller 10 that calculates a voltage reference values Vu, Vv, and Vw based on the phase angle reference value ?m calculated by the phase controller 20, and a power conversion unit 52 that converts, based on the voltage reference values Vu, Vv, and Vw calculated by the voltage controller 10, an electric power supplied from a power supply source 60 into AC power and outputs it to the distribution line 5.

Abstract: A stored power production source management device of an embodiment includes an acquisition unit, a power storage management unit, and a discharging management unit. The acquisition unit acquires first information indicating a power supply source when a power storage is charged. The power storage management unit stores information indicating a power supply source for power stored in the power storage in a data storage in association with an amount of stored power on the basis of the first information. The discharging management unit specifies a power supply source for the power to be discharged on the basis of information indicating the power supply source stored in the data storage when the power storage is discharged, and subtracts the amount of power to be discharged from the amount of power corresponding to the specified power supply source in the data storage.

Abstract: In a protective relay device for a three-terminal transmission line comprising terminal A, terminal B and terminal C, when for example terminal information is transmitted to a protective relay Ry-A of one remote terminal (terminal A) from the protective relay Ry-C of the terminal C, terminal information Db that was sent from the protective relay Ry-B of another remote terminal (terminal B) is transmitted, in addition to the information Dc of the terminal in question. In the same way, when terminal information is transmitted to a protective relay Ry-B of the terminal B from the protective relay Ry-C of the terminal C, terminal information Da that was sent from the protective relay Ry-A of the terminal A is transmitted, in addition to the information Dc of the terminal in question.

Abstract: In a protective relay device for a three-terminal transmission line comprising terminal A, terminal B and terminal C, when for example terminal information is transmitted to a protective relay Ry-A of one remote terminal (terminal A) from the protective relay Ry-C of the terminal C, terminal information Db that was sent from the protective relay Ry-B of another remote terminal (terminal B) is transmitted, in addition to the information Dc of the terminal in question. In the same way, when terminal information is transmitted to a protective relay Ry-B of the terminal B from the protective relay Ry-C of the terminal C, terminal information Da that was sent from the protective relay Ry-A of the terminal A is transmitted, in addition to the information Dc of the terminal in question.

Abstract: A current differential relay apparatus includes a ratio-differential-characteristic determining unit determining an operation in a ratio differential characteristic based on an operation level Id and a suppression level Ir, a first-current-range determining unit determining that it is activated when Id>a1Ir+b1 is satisfied, a second-current-range determining unit determining that it is activated when Id>a2Ir+b2 is satisfied with relationships a1?a2 and b1?b2 being satisfied where a1, a2, b1 and b2 are real numbers, and an AND operator, a reset unit, and a flip flop which determine that it is an operation in a ratio differential characteristic when both first and second current ranges are activated, and which continue the operation until an operation in the first range is reset.

Abstract: A current differential relay apparatus includes a ratio-differential-characteristic determining unit determining an operation in a ratio differential characteristic based on an operation level Id and a suppression level Ir, a first-current-range determining unit determining that it is activated when Id>a1Ir+b1 is satisfied, a second-current-range determining unit determining that it is activated when Id>a2Ir+b2 is satisfied with relationships a1?a2 and b1?b2 being satisfied where a1, a2, b1 and b2 are real numbers, and an AND operator, a reset unit, and a flip flop which determine that it is an operation in a ratio differential characteristic when both first and second current ranges are activated, and which continue the operation until an operation in the first range is reset.

Abstract: A distance relay apparatus includes a directional relay element which performs computation to detect a fault, which occurs in the forward direction from an installing point of the relay apparatus, based on a voltage and a current which are received from an object to be protected, a zone-1 distance relay element which performs computation to detect a fault within a predetermined zone, a fault detecting relay element which performs computation to detect a fault within a zone that is narrower than that of the zone-1 distance relay element in terms of data time length which is shorter than that used for the computation of the zone-1 distance relay element, and a logic element which outputs a relay signal in accordance with a detecting operation of the zone-1 distance relay element, the fault detecting relay element, and the directional relay element.

Abstract: A directional ground relay (50) for receiving electric values relating to voltage and current from a power transmission line (1) to be protected. The directional ground relay may decide a direction of a fault in the power transmission line based upon the electric values. The directional ground relay comprises a zero-phase sequential current calculation unit (10-2) for calculating a zero-phase sequential current based upon the current detected from the power transmission line. The directional ground relay further comprises a phase-comparison unit (10-3) configured to compare a phase of the zero-phase sequential current to a phase of voltage corresponding to the voltage in the power transmission line, to decide whether the zero-phase sequential current is within a pre-determined range, and to output the phase of the voltage as a faulty phase of voltage, when the zero-phase sequential current is within the pre-determined range.

Abstract: A digital directional relay converts a voltage value and a current value of a power system into digital voltage data and digital current data by periodic sampling and determines a direction of a fault using the digital voltage data and the digital current data. In the digital directional relay, a variation in unbalanced component voltage and a variation in unbalanced component current are computed using both voltage data at a reference point in time and voltage data at a point in time elapsed from the reference point in time by a given sampling interval and using both current data at reference time and current data at time elapsed from the reference time by a given sampling interval, respectively. A relationship in phase between these variations is obtained to determine whether a forward fault or a reverse fault occurs.

Abstract: A directional comparison distance relay system for protecting a power transmission line. The relay system comprises a fault detection unit which includes a directional distance relay element for deciding whether a fault is in forward or reverse directions; a short-circuit distance relay element for deciding whether a fault is within a protection zone by distance calculation; and an evolving fault detecting unit for deciding an evolving fault when a forward earth fault directional relay in a single phase and a reverse directional relay in a phase are in operation. The relay system further comprises a block unit for blocking trip of a circuit breaker at a near end due to the short-circuit distance relay, and for blocking permissive trip signal to a circuit breaker at the far end, based on an operation of the evolving fault detecting unit.

Abstract: In a protective relay system according to an aspect of the present invention, a direction of a fault is correctly determined during system oscillation using one of a negative-phase-sequence relay and a zero-phase-sequence relay. A circuit breaker is tripped only when an internal fault is determined at both terminals to be protected using a carrier signal. Thus, even though a fault occurs during system oscillation, the circuit breaker can be tripped against the internal fault.

Abstract: A directional ground relay (50) for receiving electric values relating to voltage and current from a power transmission line (1) to be protected. The directional ground relay may decide a direction of a fault in the power transmission line based upon the electric values. The directional ground relay comprises a zero-phase sequential current calculation unit (10-2) for calculating a zero-phase sequential current based upon the current detected from the power transmission line. The directional ground relay further comprises a phase-comparison unit (10-3) configured to compare a phase of the zero-phase sequential current to a phase of voltage corresponding to the voltage in the power transmission line, to decide whether the zero-phase sequential current is within a pre-determined range, and to output the phase of the voltage as a faulty phase of voltage, when the zero-phase sequential current is within the pre-determined range.

Abstract: A distance relay apparatus includes a directional relay element which performs computation to detect a fault, which occurs in the forward direction from an installing point of the relay apparatus, based on a voltage and a current which are received from an object to be protected, a zone-1 distance relay element which performs computation to detect a fault within a predetermined zone, a fault detecting relay element which performs computation to detect a fault within a zone that is narrower than that of the zone-1 distance relay element in terms of data time length which is shorter than that used for the computation of the zone-1 distance relay element, and a logic element which outputs a relay signal in accordance with a detecting operation of the zone-1 distance relay element, the fault detecting relay element, and the directional relay element.

Abstract: A directional comparison distance relay system for protecting a power transmission line. The relay system comprises a fault detection unit which includes a directional distance relay element for deciding whether a fault is in forward or reverse directions; a short-circuit distance relay element for deciding whether a fault is within a protection zone by distance calculation; and an evolving fault detecting unit for deciding an evolving fault when a forward earth fault directional relay in a single phase and a reverse directional relay in a phase are in operation. The relay system further comprises a block unit for blocking trip of a circuit breaker at a near end due to the short-circuit distance relay, and for blocking permissive trip signal to a circuit breaker at the far end, based on an operation of the evolving fault detecting unit.

Abstract: A digital directional relay converts a voltage value and a current value of a power system into digital voltage data and digital current data by periodic sampling and determines a direction of a fault using the digital voltage data and the digital current data. In the digital directional relay, a variation in unbalanced component voltage and a variation in unbalanced component current are computed using both voltage data at a reference point in time and voltage data at a point in time elapsed from the reference point in time by a given sampling interval and using both current data at reference time and current data at time elapsed from the reference time by a given sampling interval, respectively. A relationship in phase between these variations is obtained to determine whether a forward fault or a reverse fault occurs.