Abstract: A solar power generation control device controls a solar power generation system storing electric power generated by a solar panel in a battery. The solar power generation control device includes a detection unit configured to detect a state of the battery, and a controller configured to control, based on the state of the battery, a sleep time for temporarily stopping the solar power generation system when a predetermined sleep condition is satisfied.

Abstract: In a power system voltage reactive power monitoring control device, a balance between the power system voltage and the reactive power can be maintained even when, for example, the output of renewable energy varies over time due to the weather, or the power supply configuration or system configuration changes, and the economic efficiency can be improved. In the power system voltage reactive power monitoring control device, which supplies transmission data to individual devices capable of adjusting the voltage and the reactive power of a power system, indices indicating the stability of the power system are used to determine one or more target value restrictions, information about the target value is obtained from the target value restrictions, transmission data containing information about the target value is supplied to the individual devices, and the voltage and reactive power at the relevant installation site are adjusted by the individual devices.

Abstract: A voltage stability monitoring device, which monitors voltage stability of a power system, produces a plurality of assumed change scenarios indicating a scenario of a change that is assumed based on at least one of a system configuration of the power system and a change of a tide state, calculates the voltage stability using the assumed change scenario, calculates a voltage stability margin indicating margin degree of the voltage stability, based on the voltage stability selects an assumed change scenario with high severity of the voltage stability for each assumed change scenario, based on the voltage stability margin calculates which buses in the power system are vulnerable buses that decrease voltage stability, based on the assumed change scenario which is selected, and changes a monitoring target of the voltage stability, based on information of the vulnerable bus.

Abstract: The objective is to provide a power system voltage reactive power monitoring control device with which a balance between the power system voltage and the reactive power can be maintained even when, for example, the output of renewable energy varies over time due to the weather, or the power supply configuration or system configuration changes, and a power system voltage reactive power monitoring control device with which the economic efficiency can be improved.

Abstract: A voltage stability monitoring device for monitoring the voltage stability of a system, the device including: an assumed change scenario calculation unit for predicting the output variation of a renewable energy connected to said system and calculating an assumed change time-series power flow state on the basis of said output variation; a time-series voltage stability calculation unit for calculating a node voltage change with respect to demand at each node of said system on the basis of said power flow state calculated by said assumed change scenario calculation unit and calculating a voltage stability indicating the relationship curve between said node voltage and reactive power; and a voltage stability improvement countermeasure search unit for determining a controlled device on which an assumed control is to be performed, according to said voltage stability calculated by said time-series voltage stability calculation unit.

Abstract: An object is to accurately monitor deterioration of current or future voltage stability, by dynamically changing a bus in which current or future voltage stability deteriorates, in stability monitoring calculation of a power system.

Abstract: A panel heater with a flat metal sheet of substantially even thickness of from 0.06 to 0.2 mm and having a mesh-like radiation section formed in the central portion of the sheet, the mesh-like radiation section being composed of a plurality of units of wave-like current passageways of uniform width of approximately 2 mm from one end to the other, arranged parallel to each other and connected to each other at the crests of the wave-like current passageways so that the combined width of the passageways at the crests is twice the uniform width. The panel heater also has a pair of heat resistant boards between which the metal sheet is sandwiched; and a frame assembly joining together the heat resistant boards.