Aspects of the present invention relate to controlling a renewable energy power plant comprising a plurality of wind turbine generators (WTG)s and an energy storage system (ESS). A method includes: controlling the plurality of WTGs to stop generating power, and thereby to enter a non-exporting mode of operation of the renewable energy power plant, during which one or more auxiliary systems of the renewable energy power plant are powered to maintain at least one of the plurality of WTGs in a standby state, operable to start generating power upon demand; wherein the one or more auxiliary systems are powered during the non-exporting mode of operation.

Aspects of the present invention relate to controlling a renewable energy power plant comprising a plurality of wind turbine generators (WTG)s and an energy storage system (ESS). A method includes: controlling the plurality of WTGs to stop generating power, and thereby to enter a non-exporting mode of operation of the renewable energy power plant, during which one or more auxiliary systems of the renewable energy power plant are powered to maintain at least one of the plurality of WTGs in a standby state, operable to start generating power upon demand; wherein the one or more auxiliary systems are powered during the non-exporting mode of operation.

A method for designing a distributed communication topology of a micro-grid based on network mirroring and global propagation rates includes the following steps: first, determining the communication connectivity of distributed directed networks in the micro-grid; next, obtaining, for connected directed communication networks, mirror networks thereof based on a mirroring operation, and selecting an optimal distributed directed communication topology corresponding to a maximum performance indicator based on algebraic connectivity and communication costs; solving, for the optimized distributed communication topology, pinned distributed generation sets corresponding to different pinning numbers based on global propagation rates and out-degrees; and finally, establishing a distributed secondary voltage control of the micro-grid based on the optimal distributed communication network and pinned nodes of the micro-grid, to achieve accurate reactive power sharing and average voltage restoration.

An energy saving support system according to an embodiment is configured to provide a consumer, who has an electric load to which electric energy is supplied from an electric power supply system within a house, with energy consumption-related information through a photo frame or the like. The information providing apparatus is configured to acquire an acceptability level, which stepwise indicates a degree of interest of the consumer in the energy consumption-related information, and to determine the energy consumption-related information to be newly provided to the consumer based on the acceptability level.

An energy saving support system according to an embodiment is configured to provide a consumer, who has an electric load to which electric energy is supplied from an electric power supply system within a house, with energy consumption-related information through a photo frame or the like. The information providing apparatus is configured to acquire an acceptability level, which stepwise indicates a degree of interest of the consumer in the energy consumption-related information, and to determine the energy consumption-related information to be newly provided to the consumer based on the acceptability level.

A method for controlling an electrical transmission network including a plurality of DC high-voltage lines and at least three AC/DC converters identified by a respective index i. For each of the converters having index i, the method includes recovering the setpoint active power value Pdci applied thereto, and recovering instantaneous voltage value Vi and voltage angle value θi of the buses having index i and modifying the setpoint active power Pdci of each of the converters having index i by a value including a term ΔPdcsi as a function of a sum of deviations of voltage angles multiplied by contribution adjustment parameters.

Provided are a method and system for controlling a voltage. The method includes: acquiring a current output voltage of an inverter; calculating a current voltage error of the current output voltage relative to a given output voltage; inputting the current voltage error into a fuzzy controller to determine a target output voltage of the inverter; determining an amplitude adjustment command based on a difference between an amplitude of the target output voltage and an amplitude of the current output voltage; determining a phase adjustment command based on a difference between a phase of the target output voltage and a phase of the current output voltage; and adjusting an amplitude and a phase of an output voltage of the inverter according to the amplitude adjustment command and the phase adjustment command respectively, to maintain the output voltage of the inverter within a preset range.

Aspects of the disclosure include a power system comprising at least one three-wire active harmonic filter (AHF) configured to be coupled to, and provide compensation current to, a three-phase load, at least one four-wire AHF configured to be coupled to, and provide compensation current to, the three-phase load, and a controller configured to determine a total compensation current to provide to the three-phase load, the total compensation current including a zero component and a non-zero component, determine an output capacity of the at least one three-wire AHF and the at least one four-wire AHF, calculate a current-compensation ratio based on the output capacity of the at least one three-wire AHF and the at least one four-wire AHF, and control the at least one four-wire AHF to provide at least a portion of the non-zero component of the total compensation current to the three-phase load based on the current-compensation ratio.

A distributed power system including multiple (DC) batteries each DC battery with positive and negative poles. Multiple power converters are coupled respectively to the DC batteries. Each power converter includes a first terminal, a second terminal, a third terminal and a fourth terminal. The first terminal is adapted for coupling to the positive pole. The second terminal is adapted for coupling to the negative pole. The power converter includes: (i) a control loop adapted for setting the voltage between or current through the first and second terminals, and (ii) a power conversion portion adapted to selectively either: convert power from said first and second terminals to said third and fourth terminals to discharge the battery connected thereto, or to convert power from the third and fourth terminals to the first and second terminals to charge the battery connected thereto. Each of the power converters is adapted for serial connection to at least one other power converter by connecting respectively the third and fourth terminals, thereby forming a serial string. A power controller is adapted for coupling to the serial string. The power controller includes a control part adapted to maintain current through or voltage across the serial string at a predetermined value.

A power management method includes a step A of specifying an influence of a distributed power supply on a power demand-supply balance by a power management server, the power management server managing a plurality of facilities and the distributed power supply being individually provided in each of the plurality of facilities; and a step B of transmitting distributed power supply information from a local control apparatus to the power management server, the local control apparatus being individually provided in each of the plurality of facilities and the distributed power supply information including information indicating an operation state of the distributed power supply, wherein the step A includes a step of specifying the influence on the power demand-supply-demand balance based on the distributed power supply information.