Abstract:
A wind turbine generator 1 is connected to a section 2 of an electricity grid 3 via a converter 4, which converts the ac output power from the generator into three-phase electric power at the voltage and frequency of the grid 3. The converter 4 comprises silicon carbide transistors which act as ON-OFF switches which are controlled so as to create a voltage profile which is the same as that of the grid voltage. Each grid section 2, 2' has a respective circuit breaker 10, 10' which disconnects the associated section from the remainder of the grid 3 in the event of an abnormally high current. The converter 2 includes a fault detector 11 arranged to detect grid faults, such as an abnormally low voltage level which, in response, generates an alarm signal which causes a high-level transient current to be supplied to the grid 3 sufficient to trip the circuit breaker 10' so as to disconnect the faulty section of the grid. By using silicon carbide transistors, which can withstand high operating temperatures, a higher-level current can be generated than would be the case with converters using conventional silicon transistors.
Abstract:
A method for operating a wind turbine and a system for operating a wind turbine are provided. The wind turbine includes a grid side converter and the grid side converter is coupled to a grid via a power line. The method includes determining a wind turbine operation strategy; determining a first active power reference and a first reactive power reference indicating a requested amount of active power and reactive power, respectively, depending on at least the wind turbine operation strategy; measuring a grid voltage of the grid; determining a positive sequence component and a negative sequence component of the grid voltage i.e. a positive sequence voltage and a negative sequence voltage; determining a second active power reference and a second reactive power reference indicating an actual amount of active power and reactive power to be supplied by the grid side converter to the grid, respectively, depending on at least the first active power reference, the first reactive power reference, and the wind turbine operation strategy; generating, based on at least the wind turbine operation strategy, a first parameter and a second parameter which define a proportion of positive sequence current component and negative sequence current component to be injected by the grid side converter in order to supply active power and reactive power in accordance with the second active power reference and the second reactive power reference; generating a current reference based on at least the second active power reference, the second reactive power reference, the positive sequence voltage, the negative sequence voltage, the first parameter, and the 77 second parameter; and supplying, with the grid side converter, active and reactive power to the power line based on the current reference.
Abstract:
The present invention relates to method for operating a power plant, with at least one wind turbine generator arranged for supplying power to an electrical grid, at least one energy storage device arranged for supplying power to the electrical grid, and a power plant controller, the method comprises, measuring repetitively measurement sets of at least one electrical parameter from the electrical grid, and calculating, in respect the measurement sets of the at least one electrical parameter, a change in active and/or a required change in reactive power at a point of common coupling, and calculating and dispatching of a first control reference signal to the at least one wind turbine generator and a second control reference signal to the at least one energy storage device,for providing ancillary service functionalities to the electrical grid. The invention also relates to a power plant with at least one wind turbine generator for supplying power to an electrical grid, at least one energy storage device for supplying power to the electrical grid, and a power plant controller for providing ancillary service functionalities to the electrical grid.
Abstract:
The present invention relates to a grid monitoring system, in particular a grid monitoring system enabling real-time monitoring of grid variables, e.g. voltage and current, in electrical power systems, such as single or three-phase networks. The grid monitoring system comprises a harmonic detection unit being adapted to subtract harmonics of an input signal before feeding the input signal to a plurality of signal generators in the harmonic detection unit.
Abstract:
The present invention relates to method for operating a power plant, with at least one wind turbine generator arranged for supplying power to an electrical grid, at least one energy storage device arranged for supplying power to the electrical grid, and a power plant controller, the method comprises, measuring repetitively measurement sets of at least one electrical parameter from the electrical grid, and calculating, in respect the measurement sets of the at least one electrical parameter, a change in active and/or a required change in reactive power at a point of common coupling, and calculating and dispatching of a first control reference signal to the at least one wind turbine generator and a second control reference signal to the at least one energy storage device, for providing ancillary service functionalities to the electrical grid. The invention also relates to a power plant with at least one wind turbine generator for supplying power to an electrical grid, at least one energy storage device for supplying power to the electrical grid, and a power plant controller for providing ancillary service functionalities to the electrical grid.
Abstract:
The present invention relates to a grid monitoring system, in particular a grid monitoring system enabling real-time monitoring of grid variables, e.g. voltage and current, in electrical power systems, such as single or three-phase networks. The grid monitoring system comprises a harmonic detection unit being adapted to subtract harmonics of an input signal before feeding the input signal to a plurality of signal generators in the harmonic detection unit.
Abstract:
A method for operating a power generation system coupled to a power grid during a grid unbalance event, a method for determining an injection current to be supplied into a power grid by a power generation system, and a method for addressing an asymmetric grid fault in a power grid connected to a power generation system are provided. The methods may be carried out based on a reactive or an active power/current priority.