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 power supply system according to the present embodiment includes a plurality of first power converters configured to supply power according to dispatching characteristics of power to be supplied to a load, and a plurality of control devices each configured to associate a change ratio of active power to an output frequency of each of the first power converters with the dispatching characteristics and control each of the first power converters based on the change ratio.

Abstract: A power supply system according to the present embodiment includes a plurality of first power converters configured to supply power according to dispatching characteristics of power to be supplied to a load, and a plurality of control devices each configured to associate a change ratio of active power to an output frequency of each of the first power converters with the dispatching characteristics and control each of the first power converters based on the change ratio.

Abstract: A power supply system according to an embodiment includes at least one or more inverter-connected power sources, a controller, and a current supplier. The inverter-connected power sources are connected to a power transmission line provided in an electric grid. The controller limits, based on output states of the inverter-connected power sources, current output from the inverter-connected power sources to the power transmission line. The current supplier is connected to the power transmission line in parallel with the inverter-connected power sources and when the controller limits the current output of the inverter-connected power sources, outputs a current to the power transmission line.

Abstract: A power demand estimating apparatus includes a demand data memory, a demand estimator, and a display. The demand data memory stores plural power demand patterns and power demand amount data. The demand estimator selects, from the demand data memory, the demand pattern matching the environmental condition on an estimation day, obtains the maximum value of an power demand amount and the minimum value thereof at an expected temperature on the estimation day, calculates, using those pieces of information, the power demand amount per a unit time on the estimation day, and creates a demand estimating model. The display displays, together with the power demand pattern selected by the demand estimator, the demand estimating model.

Abstract: A power demand estimating apparatus includes a demand data memory, a demand estimator, and a display. The demand data memory stores plural power demand patterns and power demand amount data. The demand estimator selects, from the demand data memory, the demand pattern matching the environmental condition on an estimation day, obtains the maximum value of an power demand amount and the minimum value thereof at an expected temperature on the estimation day, calculates, using those pieces of information, the power demand amount per a unit time on the estimation day, and creates a demand estimating model. The display displays, together with the power demand pattern selected by the demand estimator, the demand estimating model.

Abstract: An energy management system of an embodiment includes first and second registration processors, first and second receivers, an aggregation processor, first and second transmitters, and a proration processor. The first registration processor registers a first energy management system as a host system. The second registration processor registers a second energy management system as a slave system. The first receiver receives an amount of an energy supply and demand and an adjustable amount of an energy supply and demand. The aggregation processor aggregates the received amount of an energy supply and demand and the received adjustable amount of an energy supply and demand. The first transmitter transmits aggregated results. The second receiver receives an adjustment amount of an energy supply and demand. The proration processor prorates the received adjustment amount of an energy supply and demand. The second transmitter transmits individual adjustment amounts of a power supply and demand.

Abstract: A power supply and demand control apparatus includes a power generation planning unit that calculates one day's power outputs of multiple distributed power sources and a power flow target of a linking point to another power system, a long-cycle control unit having a long-cycle supply-demand balancing control unit that performs control every few minutes so as to ensure the supply-demand balancing of electric energy in a given amount of time at the linking point in order to perform control for making deviations between total power output calculated by the power generation planning unit and load power in the power system constant, and a short-cycle control unit having a short-cycle supply-demand balancing control unit that performs similar control every few seconds. In the power supply and demand control apparatus, the long-cycle control unit and short-cycle control unit perform the supply-demand balancing control in a hierarchical fashion to determine output assignments of the distributed power sources.

Abstract: According to one embodiment, the economical load dispatcher calculates a discharging threshold value and a charging threshold value based on a discharging unit price of and a charging and discharging efficiency of the secondary battery and further calculates output allocations of the generators and secondary battery such that the secondary battery is discharged when incremental fuel costs of the generators are higher than the discharging threshold value, whereas the secondary battery is charged when incremental fuel costs of the generators are lower than the charging threshold value.

Abstract: To provide a secondary battery controlling apparatus and a controlling method that can keep a storage amount of a secondary battery used for supply and demand control of a power system not close to 100% or 0%. The present invention is a power supply and demand controlling apparatus of a small-scaled power system 1 including distributed power supplies 31, 32, . . .

Abstract: According to one embodiment, the economical load dispatcher calculates a discharging threshold value and a charging threshold value based on a discharging unit price of and a charging and discharging efficiency of the secondary battery and further calculates output allocations of the generators and secondary battery such that the secondary battery is discharged when incremental fuel costs of the generators are higher than the discharging threshold value, whereas the secondary battery is charged when incremental fuel costs of the generators are lower than the charging threshold value.

Abstract: A power supply and demand control apparatus includes a power generation planning unit that calculates one day's power outputs of multiple distributed power sources and a power flow target of a linking point to another power system, a long-cycle control unit having a long-cycle supply-demand balancing control unit that performs control every few minutes so as to ensure the supply-demand balancing of electric energy in a given amount of time at the linking point in order to perform control for making deviations between total power output calculated by the power generation planning unit and load power in the power system constant, and a short-cycle control unit having a short-cycle supply-demand balancing control unit that performs similar control every few seconds. In the power supply and demand control apparatus, the long-cycle control unit and short-cycle control unit perform the supply-demand balancing control in a hierarchical fashion to determine output assignments of the distributed power sources.

Abstract: To provide a secondary battery controlling apparatus and a controlling method that can keep a storage amount of a secondary battery used for supply and demand control of a power system not close to 100% or 0%. The present invention is a power supply and demand controlling apparatus of a small-scaled power system 1 including distributed power supplies 31, 32, . . .