An electric power control system for controlling supply and consumption of electric power in a system power supply, a storage battery and an electric power load, said electric power control system including: an estimated value correction unit configured to obtain a difference between a past power control estimated value and a past actual performance value, and to shift a power control estimated value obtained as a result of estimation in a predetermined period to an extent corresponding to said difference, thereby correcting the power control estimated value, wherein said past power control estimated value is a value obtained as a result of estimation performed in a past time relative to said predetermined period, and said past actual performance value is a value obtained as an actual result in the past time; and a power control unit configured to control supply and consumption of electric power in the system power supply, the storage battery, and the electric power load, based on the power control estimated value corrected by the estimated value correction unit.

A system includes a converter configured to be coupled between an energy storage unit and a grid and a control circuit configured to detect frequency and voltage variations of the grid and to responsively cause the converter to transfer power and reactive components to and/or from the grid. The control circuit may implement a power control loop having an inner frequency control loop and a reactive component control loop having an inner voltage control loop. The control circuit may provide feedforward from the inner frequency control loop to the inner voltage control loop to inhibit reactive component transfer in response to a voltage variation deviation of the grid due to a power transfer between the energy storage unit and the grid.

Techniques for managing an off-grid power system include executing update requests for an off-grid power system that is communicably coupled to an energy management system by determining an amount of stored energy in energy storage devices in response to at least one update request, determining an amount of electrical power generatable by renewable energy power systems in response to another update request, determining a predicted reliability of at least a portion of the energy storage devices and the renewable energy power systems in response to another update request, and determining an amount of electrical power for a remote facility that is electrically coupled to the off-grid power system in response to another update request. The techniques further include determining a control command for the off-grid power system based on the responses to the update requests; and providing the control command to the off-grid power system to adjust an operation of at least one of the energy storage devices or the renewable energy power systems.

A low-voltage circuit in a bidirectional DC-DC converter converts output AC power from a high-voltage circuit to DC power to charge a smoothing reactor and discharge the smoothing reactor, and includes an active snubber circuit including switching elements and each having a backward diode and a snubber capacitor. The snubber capacitor of the active snubber circuit has its one end connected to a drain end of the switching elements and has its other end connected to a node between a center tap of a high-frequency transformer and a smoothing reactor.

The present disclosure is directed to energy storage and supply management system. The system may include one or more of a control unit, which is in communication with the power grid, and an energy storage unit that stores power for use at a later time. The system may be used with traditional utility provided power as well as locally generated solar, wind, and any other types of power generation technology. In some embodiments, the energy storage unit and the control unit are housed in the same chassis. In other embodiments, the energy storage unit and the control unit are separate. In another embodiment, the energy storage unit is integrated into the chassis of an appliance itself.

A power converting device includes a DC-DC converting circuit, a DC-AC converting circuit, and an insulation detecting circuit. The DC-DC converting circuit is configured to convert a DC input voltage to a DC bus voltage. The DC-AC converting circuit is electrically coupled to the DC-DC converting circuit and configured to convert the DC bus voltage to an AC voltage. The insulation detecting circuit is electrically coupled between the DC-DC converting circuit and the DC-AC converting circuit. The insulation detecting circuit is configured to detect a ground impedance value of the power converting device according to the DC bus voltage.

Wind power generating equipment includes: a generator that is driven by a blade which rotates by receiving the wind; a power converter that converts an electric output of the generator such that the output is interconnected with an electric power system; a power converter controller that controls the power converter; and a wind turbine control board that transmits, to the power converter controller, an active power command value that is used as a command value of the electric output which is transmitted from the power converter. The power converter controller controls the output of the power converter in response to an active power command value, depending on a reduction amount of a system voltage when instantaneous reduction occurs in the system voltage interconnected with the wind power generating equipment. This permits stable operation of the wind power generating system when instantaneous voltage reduction occurs such as during a system abnormality.

Disclosed are a power optimization method and an apparatus therefor, and a photovoltaic device and a photovoltaic system. The power optimization of a photovoltaic assembly can be realized when a series connection architecture or a parallel connection architecture is used for the photovoltaic assembly. The method includes: power optimization apparatuses carrying out MPPT processing on photovoltaic assemblies according to operating parameters of the photovoltaic assemblies corresponding to the power optimization apparatuses on a one-to-one basis (101); and controlling the photovoltaic assemblies according to MPPT processing results so that power states of the photovoltaic assemblies are optimized (102). By means of providing a power optimization apparatus for each photovoltaic assembly, the power optimization apparatus carries out MPPT processing on the corresponding photovoltaic assembly, thereby preventing the occurrence of power mismatch.

An externally-controllable electrical power generating system for providing auxiliary or backup power to a load bus or device. The system may be used indoors, and generally includes a power source comprising a first DC output, an electrical storage unit comprising a DC input coupled to the first DC output of the power source, the electrical storage unit further comprising a second DC output. An inverter coupled to the second DC output receives power, the inverter having a first AC output that can be synchronized with an AC load bus or AC grid. The system includes a contactor connected between the first AC output and an AC load bus, and is controllable with an external controller operated by a utility or a managing entity, such that the external controller can enable the controller to connect or disconnect the contactor.

Methods for implementing power delivery transactions between a buyer and a seller of electrical energy supplied to an electrical grid by an integrated renewable energy source (RES) and energy storage system (ESS) of a RES-ESS facility are provided. Estimated total potential output of the RES is compared to a point of grid interconnect (POGI) limit to identify potential RES overgeneration, and the buyer is charged if potential RES overgeneration is less than potential overgeneration during one or more retrospective time windows. The method provides a basis for the RES-ESS facility owner to be paid for an estimated amount of energy that did not get stored as a result of a grid operator not fully discharging an ESS prior to the start of a new day.