A method for feeding electric power into an electrical supply grid by means of a local feed unit. The feed unit is connected to a grid link point connected to a transformer point directly or via a supply connection. The transformer point is connected to a grid section via a transformer. The method includes feeding electrical real power into the electrical supply grid at the grid link point, feeding electrical reactive power into the electrical supply grid at the grid link point, detecting a change to be made in the real power to be fed in, and changing the fed-in real power in accordance with the detected change to be made. The method includes limiting a change in the fed-in reactive power over time when changing the fed-in real power and/or immediately thereafter or temporarily activating voltage control on the basis of the change in the fed-in real power.

A method for feeding electric power into an electrical supply grid by means of a local feed unit. The feed unit is connected to a grid link point connected to a transformer point directly or via a supply connection. The transformer point is connected to a grid section via a transformer. The method includes feeding electrical real power into the electrical supply grid at the grid link point, feeding electrical reactive power into the electrical supply grid at the grid link point, detecting a change to be made in the real power to be fed in, and changing the fed-in real power in accordance with the detected change to be made. The method includes limiting a change in the fed-in reactive power over time when changing the fed-in real power and/or immediately thereafter or temporarily activating voltage control on the basis of the change in the fed-in real power.

A method can be used to control a flexible interconnection device that includes a number of converters. The method includes receiving a plurality of voltage signals indicating respective voltages of a plurality of load branches and a plurality of current signals indicating respective currents of the plurality of load branches, determining reference active power values for each of the plurality of converters based on the plurality of voltage signals and a plurality of reference voltage signals, determining reference reactive power values for each of the plurality of converters based on the plurality of voltage signals, the plurality of reference voltage signals and the plurality of current signals, and controlling the plurality of converters based on the determined reference active power values and the determined reference reactive power values.

A method can be used to control a flexible interconnection device that includes a number of converters. The method includes receiving a plurality of voltage signals indicating respective voltages of a plurality of load branches and a plurality of current signals indicating respective currents of the plurality of load branches, determining reference active power values for each of the plurality of converters based on the plurality of voltage signals and a plurality of reference voltage signals, determining reference reactive power values for each of the plurality of converters based on the plurality of voltage signals, the plurality of reference voltage signals and the plurality of current signals, and controlling the plurality of converters based on the determined reference active power values and the determined reference reactive power values.

A method and system for controlling voltage and reactive power for electrical grids includes monitoring the output of the energy generation facilities at the point of interconnection (POI) of each energy generation facility to the power transmission system of the electrical grid. In addition, the voltage at a point of utilization (POU) is monitored to determine when the output voltage of the energy generation facilities must be adjusted to maintain voltage at the POU. In addition, when it is determined that energy generation facilities are exchanging reactive power, the voltage set points of the energy generation facilities are adjusted to reduce the exchanged power.

A method and system for controlling voltage and reactive power for electrical grids includes monitoring the output of the energy generation facilities at the point of interconnection (POI) of each energy generation facility to the power transmission system of the electrical grid. In addition, the voltage at a point of utilization (POU) is monitored to determine when the output voltage of the energy generation facilities must be adjusted to maintain voltage at the POU. In addition, when it is determined that energy generation facilities are exchanging reactive power, the voltage set points of the energy generation facilities are adjusted to reduce the exchanged power.

A method and system for controlling voltage and reactive power for electrical grids includes monitoring the output of the energy generation facilities at the point of interconnection (POI) of each energy generation facility to the power transmission system of the electrical grid. In addition, the voltage at a point of utilization (POU) is monitored to determine when the output voltage of the energy generation facilities must be adjusted to maintain voltage at the POU. In addition, when it is determined that energy generation facilities are exchanging reactive power, the voltage set points of the energy generation facilities are adjusted to reduce the exchanged power.

A method and system for controlling voltage and reactive power for electrical grids includes monitoring the output of the energy generation facilities at the point of interconnection (POI) of each energy generation facility to the power transmission system of the electrical grid. In addition, the voltage at a point of utilization (POU) is monitored to determine when the output voltage of the energy generation facilities must be adjusted to maintain voltage at the POU. In addition, when it is determined that energy generation facilities are exchanging reactive power, the voltage set points of the energy generation facilities are adjusted to reduce the exchanged power.

It is desirable to improve the accuracy of voltage control in the grid interconnection device for supplying the power generated by the distributed power source to the interconnection point. Provided is a grid interconnection device for supplying power generated by a distributed power source to an interconnection point, comprising: a calculation unit for calculating voltage at the interconnection point based on output voltage of the grid interconnection device, output current of the grid interconnection device, and an impedance component between the grid interconnection device and the interconnection point; and a control unit for controlling output power from the grid interconnection device, based on voltage at the interconnection point calculated by the calculation unit.

It is desirable to improve the accuracy of voltage control in the grid interconnection device for supplying the power generated by the distributed power source to the interconnection point. Provided is a grid interconnection device for supplying power generated by a distributed power source to an interconnection point, comprising: a calculation unit for calculating voltage at the interconnection point based on output voltage of the grid interconnection device, output current of the grid interconnection device, and an impedance component between the grid interconnection device and the interconnection point; and a control unit for controlling output power from the grid interconnection device, based on voltage at the interconnection point calculated by the calculation unit.