Abb Schweiz Ag

Marici Holdings the Netherlands B.v.

Silvia Mastellone

Kedar Kulkarni

Carsten Franke

Adrian Vasile Timbus

Jan Poland

Yan Zhang

Pietro Raboni

Peter Al-Hokayem

David Martini

Stefan Almer

Ki-Bum Park

Helfried Peyrl

Thiago Batista Soeiro

A method for islanding detection in an electrical power grid supplied by an electrical power source. The method includes measuring an output voltage (V) and a grid current (I) at an interconnection point of the power source with the power grid; estimating at least one grid parameter from the output voltage (V) and the grid current (I) based on optimizing a cost function, which minimizes a difference between the measured output voltage (V) and an estimated output voltage or a difference between the measured grid current (I) and an estimated grid current, which estimated output voltage or estimated output current is a function of the measured grid current (I) or the measured output voltage (V) and the least one estimated grid parameter; and detecting an islanding condition by detecting a jump and/or a deviation in the at least one estimated grid parameter.

Islanding detection in an electrical power grid

The present invention relates to a method of operating a wind farm comprising an upstream and a downstream turbine, wherein the upstream turbine is operated with current operation parameters under current wind conditions, wherein the method comprises the steps of: receiving future wind conditions for a time period for the wind farm, and evaluating required operation parameters for minimising wake effect of the downstream turbine under the future wind conditions, and determining a cost coefficient for changing the operation parameters to required operation parameters under consideration of fatigue effect of the wind turbine, calculating power productions Pand P, in the predetermined time period, by the wind farm if operated with the current operation parameters under the current wind conditions and if operated with the required operation parameters under the future wind conditions, respectively, and operating the upstream turbine with the required operation parameters if the cost coefficient is lower than a cost that would be obtained by a power production increment P-P.

Optimal wind farm operation

The present invention is concerned with an operation of a wind farm with a plurality of wind turbines in view of a dynamic frequency response. According to the invention, dynamic frequency support and power production for all wind turbines in a wind farm are handled concurrently in a single optimization step and taking into account wake effects within the wind farm as well as optional wind forecast information. The dynamic frequency support capability of the entire wind farm is planned in advance according to grid requirements and power system condition changes. While existing methods de-load wind turbines with a static percentage in order to supply additional power when needed, the proposed method incorporates the dynamic frequency support into the optimal operation system of wind farm.

Wind farm inertial response

A method for controlling a modular multi-level converter comprises the steps of: collecting control input variables from the converter; transmitting the control input variables to a controller of the converter via a first communication medium; determining, in the controller, and actual state of the converter and at least one control output variable based on a model of the converter; and transmitting the control output variable to the converter for controlling the converter via a second communication medium. The model of the converter accounts for the first and/or the second communication medium.

Networked control of a modular multi-level converter

A DC/AC converter is provided with a new control device and method for managing inrush current transients during operation without requiring additional external devices or emergency operating modes forcing the DC/AC converter to shut down. The present invention is particularly, but not exclusively, aimed at grid connected DC/AC, converters, often subject to inrush current phenomena due to perturbations in the grid.

DC/AC converter comprising control means for inrush current protection

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Nussbaumen, Switzerland

Silvia Mastellone