Abstract:
The present invention relates to a method for operating a wind power facility during high- wind operations, the method comprising the steps of determining one or more operational parameters, and limiting one or more reactive power capabilities of the wind power facility to one or more predetermined reactive power values if at least one determined operational parameter differs from a predetermined value or a predetermined range. The one or more determined operational parameters may be a measured or estimated wind speed, or it may be based on at least a measured active power value and a measured generator speed. The present invention further relates to a wind power control module for carrying out the method.
Abstract:
The present invention relates to a method for operating a wind power facility in order to provide reactive power support to a power grid, the method comprising the step of increasing an amount of reactive power injected into the power grid, decreasing an amount of active power injected into the power grid by a certain amount, and dissipating and/or storing essentially said certain amount of active power in power dissipation and/or power storage means. The wind power facility may comprise a wind turbine or a wind power plant.
Abstract:
This invention concerns a method of controlling a power converter system 26 operating in an overmodulation region. The power converter system 26 comprises more than two current controllers 71, 73, 77, 79 a modulator 76 and a power converter 78, and the modulator 76 is configured to provide at least one modulated drive signal 87 to the power converter 78 based on voltage reference vector signals 82a, 82b, 82c, 82d from the more than two current controllers 71, 73, 77, 79. The method comprises determining the voltage reference vector signals 82a, 82b, 82c, 82d; determining compensated voltage reference vector signals 84a, 84b, 84c, 84d indicative of a fundamental frequency of a respective voltage reference vector signal 82a, 82b, 82c, 82d; and, determining the at least one modulated drive signal 87 based on a combination of the compensated voltage reference vector signals 84a, 84b, 84c, 84d.
Abstract:
The invention relates to a method for operating a wind turbine which comprises a power generator, a generator side converter, a grid side converter, a DC link electrically connected to an output of the generator side converter and an input of the grid side converter. The method comprises monitoring a wind turbine signal for detection of an operational condition which requires an increase of an output voltage of the grid side converter, upon detection of the operational condition, initiate an over-modulation mode wherein the grid side converter is operated with a modulation index in an over-modulation range, and upon the detection of the operational condition, initiate a DC-voltage adjustment mode wherein the a DC-voltage of the DC link is increased from a first voltage level towards a second voltage level.
Abstract:
A method, converter arrangement, and controller are disclosed for connecting an output of a converter with an electrical grid to control inrush currents into a grid filter assembly connected with the output of the converter, the electrical grid carrying an alternating current (AC) signal having one or more phases. The method includes determining a voltage of the AC signal and operating, after pre-charging a direct current (DC) link of the converter to a predetermined voltage, the converter using open-loop voltage control to produce an AC output signal that substantially matches the AC signal of the electrical grid. The open-loop voltage control is based on the determined voltage of the AC signal. The method further includes closing, after a predetermined amount of time of operating the converter using the open-loop voltage control, a switching device to thereby connect the output of the converter with the electrical grid.
Abstract:
A method of controlling a full-scale converter system in which both the grid-side inverter unit and the generator-side inverter unit have a series-connection of parallel inverters and form a generator-side and grid-side voltage-center-point at a voltage level between the inverters connected in series. The voltage-center-points are electrically connected by a center-line conductor. Conversion operation with a de-rated maximum active power-output is performed in response to at least one of (i) the grid-side inverter and (ii) the generator-side inverter of the first converter-string being disabled, by disabling active power production of at least one of (i) the grid-side inverter and (ii) the generator-side inverter of the second converter-string, or correspondingly reducing active power production of the second converter-string, thereby preventing a compensation current along the center-line conductor.
Abstract:
A wind turbine generator 1 supplies three-phase a.c. current of variable voltage and variable frequency to two pairs of rectifiers 4a, 4b and 4c, 4d which generate respective d.c. outputs connected to positive, negative and neutral d.c. conductors 6, 7, 8. The outputs from each pair of rectifiers are connected together, and the outputs from the two pairs are connected in series to create a high-voltage d.c. output. Inverters 10a, 10b, 10c, 10d then convert the d.c. power to a.c. at a fixed frequency and voltage suitable for connection to the mains grid. To reduce the effect of common-mode noise, a capacitor is connected between the 1 neutral conductor7 and earth, and a respective filter circuit 30 is connected between each of the a.c. outputs of the inverters 10a, 10b, 10c, 10d and earth. To reduce the effect of voltage surges during lightning, a surge protection device is also connected between the neutral d.c. conductor 7 and earth. Any imbalance in the current in the positive and negative conductors 6, 8 is compensated by detecting the presence of current flowing in the neutral conductor 7. Power supplied to auxiliary circuits from the output of one of the inverters, e.g. 10a, of the wind turbine is measured, and any resulting imbalance between the current in the positive and negative conductors is compensated. In the event of an earth-leakage fault in the conductors connecting the a.c. outputs of the inverters to the grid, when isolated, isolation detection relays 25 are provided.
Abstract:
A system for a wind turbine, comprising a generator (28) connected to a power converter (30) by an electrical connection (32), a circuit breaker system (69) controlling the connection between the generator and the power converter through the electrical connection, and a sensor system (66) configured to sense operational parameters, wherein the generator is a permanent magnet generator. The system further comprises a protection system (61) interfaced to the circuit breaker system and the sensing system. The protection system is configured to determine an operational mode of the wind turbine (102) by monitoring at least two parameters of: the speed of the generator, the operational status of the power converter, and the operational status of the circuit breaker system, and defining an operational mode based on the monitored parameters, determine a parameter set comprising a plurality of operational parameters (104) based on the determined operational mode, and an associated set of expected values corresponding to the parameter set, wherein the determined parameter set includes generator voltage and generator speed, determine actual values corresponding to the determined parameter set (108), identify a fault condition in the event that the determined set of actual values of the operational parameters do not correspond to the determined set of expected values of the operational parameters, and implement a protection action based on the identified fault condition.
Abstract:
METHOD OF CONTROLLING A WIND TURBINE GENERATOR A method of controlling a wind turbine generator (1) comprising a power converter (22) and at least one circuit breaker (25, 41). The method comprises determining a condition of the circuit breaker (25, 41) and modifying one or more operational parameters of the power converter (22) in accordance with the condition of the circuit breaker (25, 41). In particular, the invention proposes that the converter (22) is derated if one or more of the circuit breakers (25, 41) is close to violating a protection characteristic, thereby avoiding tripping of the circuit breaker (25, 41) and the associated lost production. [Figure 3]
Abstract:
A power reference management module (52) for a power converter (22) of a wind turbine generator (1), the power reference management module (52) comprising: an input arranged to receive multiple power reference values; a processor (58) arranged to determine, based on the received power reference values, an active power target and a reactive power target; and an output arranged to transmit the active power target and the reactive power target to the power converter (22).