A power conversion apparatus and a control method for a power conversion apparatus to reduce an amplitude of an output voltage of a converter when a grid is recovered from a fault, to ensure device safety. The power conversion apparatus includes a controller and a converter, and the controller is connected to the converter. The controller is configured to: after the output voltage of the converter is less than a first threshold, when the output voltage of the converter rises to be greater than a second threshold, reduce an active current output by the converter to a first current value, and reduce a reactive current output by the converter to a second current value, where the second threshold is greater than the first threshold.

A method of power transfer control among a plurality of power sources coupled through a distribution system. The method comprises determining, at each power source of the plurality of power sources, an assignment of priorities for each of the plurality of power sources. The method also comprises obtaining, at each power source, information indicating an availability of each of the plurality of power sources and determining a set of available power sources, and identifying, at each power source, a preferred power source and a standby power source from the plurality of power sources. The method further comprises determining to change the preferred power source from a first power source to a second power source in response to detecting a condition, and conducting the power transfer.

A method of power transfer control among a plurality of power sources coupled through a distribution system. The method comprises determining, at each power source of the plurality of power sources, an assignment of priorities for each of the plurality of power sources. The method also comprises obtaining, at each power source, information indicating an availability of each of the plurality of power sources and determining a set of available power sources, and identifying, at each power source, a preferred power source and a standby power source from the plurality of power sources. The method further comprises determining to change the preferred power source from a first power source to a second power source in response to detecting a condition, and conducting the power transfer.

A photovoltaic power system includes a DC/AC inverter circuit, N DC/DC converter circuits that are located at a previous stage of the DC/AC inverter circuit and that are respectively connected to photovoltaic strings, and a controller connected to the DC/AC inverter circuit and the N DC/DC converter circuits. The controller is configured to: perform MPPT control on n DC/DC converter circuits, and perform CPG control on (N−n) DC/DC converter circuits. In the two control manners, a fast and accurate power reserve or limit of a photovoltaic string inverter with any illumination intensity and ambient temperature can be implemented, and fluctuation of a DC bus voltage and AC output power of the photovoltaic string inverter can be eliminated. Control on a virtual synchronous generator of the photovoltaic string inverter is implemented, and a lifespan of the photovoltaic string inverter is prolonged, without a need to add an energy storage element.

Techniques are described for incorporating distribution network analysis in the demand response scheduling process. In one example, a method includes receiving demand response (DR) request from a DR initiator, transmitting the DR request to an aggregator, for each customer, receiving customer location information and a customer DR value from the aggregator, aggregating DR at a distribution transformer in a distribution system, determining if there are any violations in the distribution system, determining an aggregated DR value for each electric node affected by the DR request, and transmitting each determined DR value to the DR initiator.

A wind farm comprises a plurality of wind turbines connected to a network internal to the wind farm, a network feed-in point in the network internal to the wind farm for feeding electrical power into a supply network, a control device associated with the network feed-in point designed to control the wind turbines feeding power into the supply network by the network feed-in point on the basis of measured values recorded at the network feed-in point, and at least one additional network feed-in point having an additional control device designed to control the wind turbines feeding power into the supply network by the additional network feed-in point on the basis of measured values recorded at the additional network feed-in point, wherein the network internal to the wind farm is designed to variably connect at least one wind turbine to one of the plurality of network feed-in points.

Provided are a power control method and apparatus for a wind farm. The power control method includes: calculate an adjustable power range for each wind turbine according to a current power output state of each wind turbine in the wind farm, in response to receiving a whole-farm active power adjustment signal for the wind farm sent by a power grid; and calculate a power allocated to each wind turbine based on the adjustable power range for each wind turbine and a whole-farm target power indicated by the whole-farm active power adjustment signal, so as to generate an active power adjustment command and send the generated active power adjustment command to each wind turbine.

A method may include obtaining irradiance data at a first time and a second time from sensors, determining whether one or more solar modules of a plurality of networked power plants will be covered by a shadow or shade at a third time based on the irradiance data, and generating, based on the determination, a power output prediction for each power plant of the networked power plants at the third time. The method may further include receiving power delivery profiles for first and second loads, adjusting a power output of one or more power plants of the networked power plants based at least in part on the power output prediction and the power delivery profiles for the first and second loads, and allocating a combined power output of the power plants to the first and second loads based on first and second load reliability thresholds.

A photovoltaic power plant and a secondary frequency modulation control method therefor are disclosed. The photovoltaic power plant includes a photovoltaic power station and an active power control system, wherein the photovoltaic power station includes a photovoltaic array and a photovoltaic inverter, the photovoltaic inverter being used for converting direct-current electric energy generated by the photovoltaic array into alternating-current electric energy; and the active power control system is used for performing power allocation on the photovoltaic inverter based on a power control AGC instruction value when running data of the photovoltaic power plant meets a pre-set secondary frequency modulation condition, and adjusting an active power output from the photovoltaic inverter based on an AGC instruction value of the photovoltaic inverter subjected to power allocation. The photovoltaic power station can improve the accuracy of power control and the stability of a power system.

A photovoltaic power plant and a secondary frequency modulation control method therefor are disclosed. The photovoltaic power plant includes a photovoltaic power station and an active power control system, wherein the photovoltaic power station includes a photovoltaic array and a photovoltaic inverter, the photovoltaic inverter being used for converting direct-current electric energy generated by the photovoltaic array into alternating-current electric energy; and the active power control system is used for performing power allocation on the photovoltaic inverter based on a power control AGC instruction value when running data of the photovoltaic power plant meets a pre-set secondary frequency modulation condition, and adjusting an active power output from the photovoltaic inverter based on an AGC instruction value of the photovoltaic inverter subjected to power allocation. The photovoltaic power station can improve the accuracy of power control and the stability of a power system.