Method for testing a rotor blade ice detection system as well as rotor blade ice detection system and wind turbine for carrying out the method

1. A method for testing a rotor blade ice detection system for a wind turbine having a rotor blade, the rotor blade ice detection system being configured to monitor the rotor blade and output a warning in the event of icing or damage to the rotor blade being monitored, the method comprising the steps of:

acquiring data relating to the rotor blade to be monitored;

providing at least one value of at least one of an operating and an environmental parameter;

modifying the at least one value so as to cause the at least one modified value to differ from an actual value of the parameter and to cause the at least one modified value to represent icing of the rotor blade;

evaluating the data and the at least one modified value via the rotor blade ice detection system; and,

testing whether the rotor blade ice detection system outputs a warning as a result of said at least one modified value in combination with said data being evaluated via the rotor blade ice detection system.

2. The method of claim 1 , wherein said evaluating the data via the rotor blade ice detection system includes determining a real natural frequency of the rotor blade to be monitored.

3. The method of claim 1 , wherein said evaluation of the at least one modified value via the rotor blade ice detection system includes determining an expected natural frequency of the rotor blade to be monitored.

4. The method of claim 2 , wherein:

said evaluation of the at least one modified value via the rotor blade ice detection system includes determining an expected natural frequency of the rotor blade to be monitored; and,

the rotor blade ice detection system outputs a warning if the real natural frequency is lower than the expected natural frequency.

5. The method of claim 1 , wherein the wind turbine has a sensor arranged on or in the rotor blade; and, the at least one value includes an environmental parameter provided by the sensor.

6. The method of claim 1 , wherein the at least one value includes a measured real temperature; and, the at least one modified value includes a modified temperature which is lower than the measured real temperature.

7. The method of claim 1 , wherein said modifying the at least one value is carried out by the rotor blade ice detection system.

8. A rotor blade ice detection apparatus for monitoring a rotor blade of a wind turbine, the rotor blade ice detection apparatus comprising:

a sensor configured to capture data and be arranged on or in the rotor blade;

an interface configured to read in values of at least one parameter;

said at least one parameter being at least one of an operating parameter and an environmental parameter;

an evaluation unit configured to evaluate the data captured by said sensor and the values read in by said interface for evidence of icing of the rotor blade;

said evaluation unit being configured to output a warning in the event of evidence of icing of the rotor blade;

a modification device configured to modify at least one of the values read in via said interface so as to cause the at least one modified value to differ from an actual value of said at least one said operating parameter and said environmental parameter and to cause the at least modified value to represent an icing of the rotor blade; and,

said modification device being configured to provide said evaluation unit with said at least one modified value for evaluation in a test mode, wherein it is determined whether said evaluation unit outputs the warning in response to evaluating the at least one modified value in combination with said data.

9. A wind turbine comprising:

a rotor blade;

a rotor blade ice detection apparatus for monitoring said rotor blade;

said rotor blade ice detection apparatus having a sensor, an interface, an evaluation unit, and a modification device;

said sensor being configured to capture data and be arranged on or in the rotor blade;

said interface being configured to read in values of at least one parameter;

said at least one parameter being at least one of an operating parameter and an environmental parameter;

said evaluation unit being configured to evaluate the data captured by said sensor and the values read in by said interface for evidence of icing of said rotor blade;

said evaluation unit being configured to output a warning in the event of evidence of icing of the rotor blade;

said modification device being configured to modify at least one of the values read in via said interface so as to cause the at least one modified value to differ from an actual value of said at least one said operating parameter and said environmental parameter and to cause the at least modified value to represent an icing of the rotor blade; and,

said modification device being configured to provide said evaluation unit with said at least one modified value for evaluation in a test mode, wherein it is determined whether said evaluation unit outputs the warning in response to evaluating the at least one modified value in combination with said data.