A method performed in an electrical microgrid for facilitating connection of a first and second AC power networks. The method includes, when the power networks are disconnected, from the second power network, controlling the AC frequency of the first power network based on the AC frequency of the second power network for ensuring that when the first and second networks are connected power will flow from the power network of the first and second power networks having a higher frequency to the power network of the first and second power networks having a lower frequency. The method also includes, after the controlling, connecting the first power network to the second power network, whereby power, at the instant of connecting, flows from the power network of the first and second power networks having a higher frequency to the power network of the first and second power networks having a lower frequency.

A method performed in an electrical microgrid for facilitating connection of a first and second AC power networks. The method includes, when the power networks are disconnected, from the second power network, controlling the AC frequency of the first power network based on the AC frequency of the second power network for ensuring that when the first and second networks are connected power will flow from the power network of the first and second power networks having a higher frequency to the power network of the first and second power networks having a lower frequency. The method also includes, after the controlling, connecting the first power network to the second power network, whereby power, at the instant of connecting, flows from the power network of the first and second power networks having a higher frequency to the power network of the first and second power networks having a lower frequency.

The present invention relates to the field of generator technology. It is an object of the invention to control the stability in an electric grid in which a plurality of generators are connected providing electric power to the grid. A static exciter system includes a control device for controlling the field voltage of the field winding of at least two generators connected to a grid system via a busbar.

The present invention relates to the field of generator technology. It is an object of the invention to control the stability in an electric grid in which a plurality of generators are connected providing electric power to the grid. A static exciter system includes a control device for controlling the field voltage of the field winding of at least two generators connected to a grid system via a busbar.

A controller for individual sites of the microgrid controls loads, sources, the importing of power, and the exporting of power as a function of the energy storage at the site. A microgrid of such sites provides the benefits of improved energy storage without the need for real-time communication between sites.

A controller for individual sites of the microgrid controls loads, sources, the importing of power, and the exporting of power as a function of the energy storage at the site. A microgrid of such sites provides the benefits of improved energy storage without the need for real-time communication between sites.

A code modulator transmits power to at least one code demodulator via a transmission path. The code modulator is provided with: a code modulation circuit to which output power of a power supply is supplied, the code modulation circuit modulating the output power of the power supply to generate a code-modulated wave by code modulation using a modulation code based on a code sequence, and transmitting the code-modulated wave to the code demodulator via the transmission path; and a control circuit that controls the code modulation circuit. The control circuit sets a frequency of the modulation code to a multiple of an output power frequency of the power supply.

A code modulator transmits power to at least one code demodulator via a transmission path. The code modulator is provided with: a code modulation circuit to which output power of a power supply is supplied, the code modulation circuit modulating the output power of the power supply to generate a code-modulated wave by code modulation using a modulation code based on a code sequence, and transmitting the code-modulated wave to the code demodulator via the transmission path; and a control circuit that controls the code modulation circuit. The control circuit sets a frequency of the modulation code to a multiple of an output power frequency of the power supply.

Electrically connecting a first node of a first power grid to a second node of a second power grid includes: determining a phase angle of at least one phase of an AC voltage at the first node in the first power grid; determining a phase angle of at least one phase of an AC voltage at the second node in the second power grid; determining a phase angle metric based on comparing the phase angle of the AC voltage in the first power grid to the phase angle of the AC voltage in the second power grid; comparing the phase angle metric to a phase angle threshold; and if the phase angle metric is equal to or exceeds the phase angle threshold, controlling a dispatchable energy source in the first power grid in a P-Q control mode to adjust the phase angle of at least one phase of the AC voltage at the first node.

A method for supplying power at a network connection point into an electric supply network having a network frequency by means of a converter-controlled generator unit, in particular a wind turbine, comprising the following steps: supplying electric power depending on a control function, wherein the electric power can comprise active and reactive power, and a selection can be made between a normal control function and at least one frequency-maintaining control function differing from the normal control function as a control function, and the normal control function is selected if it has been recognized that the electric supply network is operating in a normal state, and the frequency-maintaining control function is selected if a steady-frequency operating state is present or is being prepared, wherein a steady-frequency operating state describes an operating state particularly of the electric supply network in which the network frequency is to be maintained at a constant value.