Abstract: An arc detection circuit includes a current detector and arc determination unit. The current detector detects a current flowing through a transmission line which connects an electric power supply device and an electric power conversion circuit. The arc determination unit calculates, from a result of measurement of the current, an area of interest and an area for comparison. The area of interest is an area of a region of interest defined by a predetermined frequency range and predetermined time for determination. The area for comparison is an area of a portion in which detected strength exceeds a predetermined strength threshold in the region of interest. The arc determination unit determines an electric arc has occurred when a ratio between the area of interest and the area for comparison exceeds a predetermined area-ratio threshold.

Abstract: An arc detection circuit includes a current detector and arc determination unit. The current detector detects a current flowing through a transmission line which connects an electric power supply device and an electric power conversion circuit. The arc determination unit calculates, from a result of measurement of the current, an area of interest and an area for comparison. The area of interest is an area of a region of interest defined by a predetermined frequency range and predetermined time for determination. The area for comparison is an area of a portion in which detected strength exceeds a predetermined strength threshold in the region of interest. The arc determination unit determines an electric arc has occurred when a ratio between the area of interest and the area for comparison exceeds a predetermined area-ratio threshold.

Abstract: A frequency control method for use in a frequency control system including: a server that receives, from a power system operator, a power command for controlling a frequency of a power grid within a predetermined frequency; at least one distributed energy resource; and a local controller connected to the server through a communication network and to the at least one distributed energy resource, the frequency control method includes: receiving the power command from the power system operator; obtaining a frequency measurement of the power grid; predicting a next power command using the frequency measurement, before the next power command is received from the power system operator; and controlling an input or output of the at least one distributed power energy resource using the predicted next power command, before the next power command is received from the power system operator.

Abstract: A charge/discharge control device according to an aspect of the present disclosure is equipped with a system frequency measurer 303 that measures a system frequency, a base frequency updater 304 that updates a base frequency, a frequency bias calculator 305 that calculates a frequency bias indicating the difference between the base frequency and the system frequency, a charge/discharge command value decider 306 that uses the frequency bias to decide a power command value, and a charge/discharge controller 307 that causes a power storage system to charge/discharge power.

Abstract: Provided is a frequency regulation method for regulating a frequency of a power system so that the frequency approximates to a rated frequency, the method including: measuring the frequency; obtaining an SOC (state of charge) of a storage battery; determining a base-point of power to be charged in or discharged from the storage battery when the measured frequency is equal to a predetermined rated frequency; determining a control variable changed from the base-point by an amount corresponding to a frequency deviation that is a difference between the predetermined rated frequency and the measured frequency; and charging or discharging the storage battery based on the control variable, wherein in the determining a base-point, a third rate of change is smaller than a first rate of change and a second rate of change that are average rates of change in the base-point with respect to the SOC when the SOC is within a first range and a second range, respectively.

Abstract: A storage battery controller includes a charging/discharging rate setter which sets a rate at which the battery is charged/discharged to approximate the power system frequency to rated frequency; and a charge and discharge controller which controls charge and discharge of the battery, in which the gain adjuster: when the measured charge level is lower than a lower limit of a normal range and the obtained power system frequency is within a first non-sensitive zone ranging from a first frequency lower than the rated frequency to the rated frequency, decreases the charging rate to a predetermined percentage of the charging rate; and when the measured frequency is higher than an upper limit of the normal range and the obtained power system frequency is within a second non-sensitive zone ranging from a second frequency higher than the rated frequency to the rated frequency, adjusts the discharging rate to decrease the discharging rate.

Abstract: A storage battery controller includes a charging/discharging rate setter which sets a rate at which the battery is charged/discharged to approximate the power system frequency to rated frequency; and a charge and discharge controller which controls charge and discharge of the battery, in which the gain adjuster: when the measured charge level is lower than a lower limit of a normal range and the obtained power system frequency is within a first non-sensitive zone ranging from a first frequency lower than the rated frequency to the rated frequency, decreases the charging rate to a predetermined percentage of the charging rate; and when the measured frequency is higher than an upper limit of the normal range and the obtained power system frequency is within a second non-sensitive zone ranging from a second frequency higher than the rated frequency to the rated frequency, adjusts the discharging rate to decrease the discharging rate.

Abstract: A frequency control method for use in a frequency control system including: a server that receives, from a power system operator, a power command for controlling a frequency of a power grid within a predetermined frequency; at least one distributed energy resource; and a local controller connected to the server through a communication network and to the at least one distributed energy resource, the frequency control method includes: receiving the power command from the power system operator; obtaining a frequency measurement of the power grid; predicting a next power command using the frequency measurement, before the next power command is received from the power system operator; and controlling an input or output of the at least one distributed power energy resource using the predicted next power command, before the next power command is received from the power system operator.

Abstract: A current control device is a current control device which supplies current to a load device by controlling a current source including a first electric appliance and a voltage source including a second electric appliance. The current control device includes: an obtaining unit which obtains information indicating non-linear components included in load current that is current supplied to the load device; a determining unit which determines a first current that includes the non-linear components; and a notifying unit which notifies the current source of a command value for causing the current source to output the first current to cause the current source to output the first current.

Abstract: Provided is a frequency regulation method for regulating a frequency of a power system so that the frequency approximates to a rated frequency, the method including: measuring the frequency; obtaining an SOC of a storage battery; determining a base-point of power to be charged in or discharged from the storage battery; determining a control variable changed from the base-point by an amount corresponding to a frequency deviation that is a difference between the rated frequency and the measured frequency; and charging or discharging the storage battery based on the control variable, wherein in the determining of a base-point, a third rate of change is smaller than a first rate of change and a second rate of change that are average rates of change in the base-point with respect to the SOC when the SOC is within a first range and a second range, respectively.

Abstract: A charge/discharge control device according to an aspect of the present disclosure is equipped with a system frequency measurer 303 that measures a system frequency, a base frequency updater 304 that updates a base frequency, a frequency bias calculator 305 that calculates a frequency bias indicating the difference between the base frequency and the system frequency, a charge/discharge command value decider 306 that uses the frequency bias to decide a power command value, and a charge/discharge controller 307 that causes a power storage system to charge/discharge power.

Abstract: The control device includes: an acquisition unit which acquires voltage information indicating a voltage applied to a capacitor provided between a power generation unit and a load via first and second power supply lines, and deterioration information indicating a state of deterioration of a storage battery connected to the power generation unit; a determination unit which compares the acquired voltage information with a reference voltage so as to detect a fluctuation of the voltage, and determines power to be outputted so as to suppress the fluctuation; and an informing unit which informs the storage battery of a current value corresponding to the power to be outputted, wherein the determination unit detects the state of deterioration of the storage battery using the deterioration information, and determines power to be outputted in accordance with the state of deterioration.

Abstract: The supply-and-demand control apparatus includes an obtaining unit that obtains power consumption and heat consumption; a forecast processing unit that obtains demand forecast data on each of electric power and an amount of heat using the power consumption and heat consumption, respectively; and a supply-and-demand planning unit that calculates a control parameter for controlling operations of an electricity storage system and a heat pump that supplies heat to a hot water storage tank, by substituting the calculated demand forecast data into a predetermined function. Additionally, a supply-and-demand control unit controls the operations using the control parameter, wherein the supply-and-demand planning unit calculates the control parameter such that electric power generated by a solar power system is distributed to the electricity storage system and the heat pump.

Abstract: The electric power conditioning device, connected to an apparatus and an electric storage device in a house, comprises an electric power receiving section, a communication section and an operation section. The electric power receiving section, connected to a commercial power supply, acquires a total electric power consumption amount of the commercial power supply. The operation section makes comparison as to whether an integrated value obtained by integrating the total electric power consumption amount and an electric power consumption amount which is an amount of electric power expected to be consumed when the apparatus is operated exceeds a predetermined value. When the integrated value does not exceed, the operation section transmits a use permission signal to the apparatus via the communication section. When the integrated value exceeds, the electric power conditioning device transmits to the electric storage device a supply electric power inquiring signal via the communication section.

Abstract: In an electric power storage system connected to a commercial power system, a controller includes a deterioration price holding unit that holds discharge costs in association with depths of discharge of a storage battery, a price information obtaining unit that obtains a price of electricity, and a depth-of-discharge switching unit that discharges the storage battery at a depth of discharge at which the discharge cost held in association with the depth of discharge does not exceed a difference in the price, so as to properly determine the depth of charge and discharge in consideration of life properties of the battery and the difference in the price in the dynamically changing price of electricity.

Abstract: A current control device is a current control device which supplies current to a load device by controlling a current source including a first electric appliance and a voltage source including a second electric appliance. The current control device includes: an obtaining unit which obtains information indicating non-linear components included in load current that is current supplied to the load device; a determining unit which determines a first current that includes the non-linear components; and a notifying unit which notifies the current source of a command value for causing the current source to output the first current to cause the current source to output the first current.

Abstract: The control device (105) includes: an acquisition unit (201) which acquires voltage information indicating a voltage applied to a capacitor provided between a power generation unit and a load via first and second power supply lines, and deterioration information indicating a state of deterioration of a storage battery connected to the power generation unit; a determination unit (202) which compares the acquired voltage information with a reference voltage so as to detect a fluctuation of the voltage, and determines power to be outputted so as to suppress the fluctuation; and an informing unit (203) which informs the storage battery of a current value corresponding to the power to be outputted, wherein the determination unit (202) detects a state of deterioration of the storage battery using the deterioration information, and determines power to be outputted in accordance with the state of deterioration.

Abstract: In an electric power storage system connected to a commercial power system, a controller (14) includes a deterioration price holding unit (14a) that holds discharge costs in association with depths of discharge of a storage battery (13), a price information obtaining unit (14b) that obtains a price of electricity, and a depth-of-discharge switching unit (14c) that discharges the storage battery at a depth of discharge at which the discharge cost held in association with the depth of discharge does not exceed a difference in the price, so as to properly determine the depth of charge and discharge in consideration of life properties of the battery and the difference in the price in the dynamically changing price of electricity.

Abstract: The supply-and-demand control apparatus (100) includes: an obtaining unit (201g) that obtains power consumption and heat consumption; a forecast processing unit (201h) that obtains demand forecast data on each of electric power and an amount of heat using the power consumption and heat consumption, respectively; a supply-and-demand planning unit (200) that calculates a control parameter (the fourth and fifth columns in FIG. 7) for controlling operations of an electricity storage system (102) and a heat pump (104) that supplies heat to a hot water storage tank (105), by substituting the calculated demand forecast data into a predetermined function; and a supply-and-demand control unit (204) that controls the operations using the control parameter, wherein the supply-and-demand planning unit (200) calculates the control parameter such that electric power generated by a solar power system (101) is distributed to the electricity storage system (102) and the heat pump (104).

Abstract: A supply-and-demand control apparatus (100) is used that includes an input-output relationship obtaining unit (1001) that obtains information (100i) on energy input-output relationships between a plurality of energy devices including an added energy device, an operation planning unit (1002) that calculates, from the information (100i), the values of control parameters to the plurality of energy devices including the added device, and a supply-and-demand control unit (1003) that sends the calculated values as commands to the plurality of energy devices including the added device.