Method of operating a wind park
View Patent ↗A method of operating a wind park having a plurality of wind turbines is provided. The method includes determining a grid condition indicator indicative of the condition of a grid into which the wind park feeds; determining a first maximum power value of the wind park on the basis of the grid condition indicator; determining an operating margin on the basis of the grid condition indicator, for a grid condition indicator indicative of a weak grid; determining a second maximum power value on the basis of the operating margin; and curtailing the active power output of the wind park according to a maximum power value. A computer program product for carrying out the steps of such a method; an active power controller adapted for use in operating a wind turbine of a wind park; a wind turbine; and a wind park are also provided.
1. A method of operating a wind park comprising a plurality of wind turbines, which method comprises:
determining by an active power controller:
a grid condition indicator indicative of a condition of a grid into which the wind park feeds;
a first maximum power value of the wind park based on the grid condition indicator wherein the first maximum power value is the maximum active power that is allowed to be transferred to the grid;
an operating margin based on the grid condition indicator and;
a second maximum power value based on the operating margin wherein the second maximum power value is a power limit for a wind turbine of the plurality of wind turbines; and
curtailing by the active power controller an active power output of the wind park to a lowest maximum power value between the first maximum power value and the second maximum power value that is associated with stable operation of the wind park when the grid condition indicator is indicative of a weak grid.
2. The method according to claim 1 , wherein the grid condition indicator is based on a short-circuit-ratio of a power network to which the wind park is connected.
3. The method according to claim 1 , wherein the grid condition indicator is based on a reactance-to-resistance ratio of a power network to which the wind park is connected.
4. The method according to claim 1 , wherein the grid condition indicator is based on a voltage profile at the connection point of the wind park or a voltage profile within the wind park.
5. The method according to claim 1 , wherein the grid condition indicator is based on a voltage-dependent active/reactive power capability of the wind turbines of the wind park.
6. The method according to claim 1 , wherein the grid condition indicator is dynamically determined in a real-time manner.
7. The method according to claim 1 , wherein an active power output of a wind turbine of the wind park is curtailed to the first maximum power value by a wind park controller.
8. The method according to claim 1 , wherein the operating margin comprises a reactive current margin derived from one or more parameters from the set of parameters comprising: short-circuit ratio; ratio of reactance to resistance; voltage stability margin; and voltage profile at a point of common coupling.
9. The method according to claim 8 , further comprising providing a look-up-table to a controller, which look-up-table relates operating margin values to one or more parameters from the set of parameters.
10. The method according to claim 1 , wherein an active power output of a wind turbine is curtailed to the second maximum power value by a wind turbine controller when the operating margin exceeds a current reserve of that wind turbine.
11. The method according to claim 1 wherein, the wind park comprising multiple connection points to power networks, the method comprises switching a feeder line from a first connection point to a second connection point.
12. A computer program product comprising a non-transitory computer readable medium having instructions thereon for carrying out the method according to claim 1 , when the computer program product is loaded into a memory of a programmable device of a wind turbine controller and/or a wind park controller.
13. An active power controller adapted for use in operating a wind turbine of a wind park, which controller programmed to:
determine a grid condition indicator indicative of a condition of a grid into which the wind park feeds;
determine a first maximum power value of the wind park based on the basis of the grid condition indicator wherein the first maximum power value is the maximum active power that is allowed to be transferred to the grid;
determine an operating margin based on the basis of the grid condition indicator;
determine a second maximum power value based on the basis of the operating margin wherein the second maximum power value is the power limit for the wind turbine; and
indicate a curtailment of an active power output of the wind park according to a lowest maximum power value between the first maximum power value and the second maximum power value for a grid condition indicator indicative of a weak grid.
14. A wind turbine arranged in a wind park and comprising a wind turbine controller, which wind turbine controller comprises an active power controller according to claim 13 .
15. A wind park comprising a plurality of wind turbines and a wind park controller, wherein the wind park controller comprises an active power controller according to claim 13 .