Multi-port power adapters. At least one example is a method including: supplying a first bus voltage to a first device by way of a DC-DC converter coupled to a link voltage; supplying a second bus voltage to a second device by way of a second DC-DC converter coupled to the link voltage; converting an AC voltage to the link voltage by way of an AC-DC converter; selecting, by a shunt regulator, a setpoint for the link voltage based on the first bus voltage and the second bus voltage; and regulating the link voltage to the setpoint by the AC-DC converter.

Provided is a method of feeding electric reactive power using a wind farm comprising wind turbines. The wind farm feeds a wind farm active power output and the wind farm active power output includes individual plant active power outputs each generated by one of the wind turbines. The wind farm feeds a wind farm reactive power output into the electrical supply network and the wind farm reactive power output includes individual plant reactive power outputs each generated by one of the wind turbines. The method includes determining a total wind farm reactive power output to be fed in by the wind farm and calculating, for each wind turbine, an individual plant reactive power output to be generated. The individual plant reactive power output is determined depending on the individual plant active power output and depending on the wind farm reactive power output to be fed in.

A method of transmitting reactive power between at least one wind turbine and a power system through a transformer connected between the at least one wind turbine and the power system, the wind turbine including a power converter. The method includes a second step of connecting at least one passive device to the transformer and reducing or increasing a reactive power of the power converter of an amount corresponding to the reactive contribution from the passive device.

A method of transmitting reactive power between at least one wind turbine and a power system through a transformer connected between the at least one wind turbine and the power system, the wind turbine including a power converter. The method includes a second step of connecting at least one passive device to the transformer and reducing or increasing a reactive power of the power converter of an amount corresponding to the reactive contribution from the passive device.

A grid-forming wind turbine control method for a diode rectifier unit-based offshore wind power transmission system. A control system for controlling a grid-side converter has a three-layered structure, where a first layer is a combination of an active power controller and a reactive power controller; a second layer is a voltage controller; and a third layer is a current controller. The actual reactive power is represented by a per-unit value of a capacity of a corresponding wind turbine unit. The wind turbine units have the same reactive-power reference value, which is constant and does not change with time. The reactive power controllers of all wind turbine units have the same structure and parameters.

A grid-forming wind turbine control method for a diode rectifier unit-based offshore wind power transmission system. A control system for controlling a grid-side converter has a three-layered structure, where a first layer is a combination of an active power controller and a reactive power controller; a second layer is a voltage controller; and a third layer is a current controller. The actual reactive power is represented by a per-unit value of a capacity of a corresponding wind turbine unit. The wind turbine units have the same reactive-power reference value, which is constant and does not change with time. The reactive power controllers of all wind turbine units have the same structure and parameters.

The present invention provides a power control circuit connectable to a load adapted to receive a power supply, the power control circuit adapted to absorb power from the power supply and adapted to deliver power to the power supply to stabilize at least one electrical parameter of the power supply. The present invention also provides an associated method of stabilizing at least one electrical parameter of a power supply connectable to a load, the method including absorbing power from the power supply or delivering power to the power supply. The at least one electrical parameter of the power supply includes parameters such as voltage and frequency.

The present invention provides a power control circuit connectable to a load adapted to receive a power supply, the power control circuit adapted to absorb power from the power supply and adapted to deliver power to the power supply to stabilize at least one electrical parameter of the power supply. The present invention also provides an associated method of stabilizing at least one electrical parameter of a power supply connectable to a load, the method including absorbing power from the power supply or delivering power to the power supply. The at least one electrical parameter of the power supply includes parameters such as voltage and frequency.

In order to output sufficient reactive power for voltage stabilization of a utility grid, and calculate an appropriate consideration according to an amount of the output reactive power, is provided a control device for controlling a distributed power source connected to the utility grid, comprising: a range setting unit where an allowable range of reactive and active powers output at normal times is set; an output control unit for controlling the reactive and active powers supplied from the distributed power source to the utility grid within the allowable range set in the range setting unit; and a reception unit for receiving, from a command device in the utility grid, an excess output command indicating that the reactive power exceeding the allowable range should be output, wherein the output control unit is for outputting the reactive power out of the allowable range when the reception unit receives the excess output command.

In order to output sufficient reactive power for voltage stabilization of a utility grid, and calculate an appropriate consideration according to an amount of the output reactive power, is provided a control device for controlling a distributed power source connected to the utility grid, comprising: a range setting unit where an allowable range of reactive and active powers output at normal times is set; an output control unit for controlling the reactive and active powers supplied from the distributed power source to the utility grid within the allowable range set in the range setting unit; and a reception unit for receiving, from a command device in the utility grid, an excess output command indicating that the reactive power exceeding the allowable range should be output, wherein the output control unit is for outputting the reactive power out of the allowable range when the reception unit receives the excess output command.