Estimating a characteristic of a wind turbine electrical signal
AssigneeVestas Wind Systems A/S
InventorsTorsten Lund, John Godsk Nielsen
Life of this patent
Estimating the term…
Abstract
A method and apparatus for estimating a characteristic of a wind turbine electrical signal comprises buffering a sequence of sample values of the wind turbine electrical signal and a sequence of sample times corresponding with the sequence of sample values. The time periods represented by the sample times are variable. A sub-sequence of the buffered sample values to integrate is determined, based at least in part on a sum of the time periods. The characteristic is estimated by integrating the sample values in the sub-sequence.
Claims19
A method of estimating a characteristic of an electrical signal of a wind turbine, the method comprising:
- buffering a sequence of sample values of the wind turbine electrical signal in one or more buffers;
- buffering a sequence of sample times corresponding with the sequence of sample values in the one or more buffers, wherein time periods represented by the sample times are variable;
- determining a sub-sequence of the buffered sample values to integrate by:
- updating a time integrator by adding to a value of the time integrator a time period represented by a sample time of the sequence of sample times;
- and
- until a value of the time integrator is less than or equal to an integration period, repeatedly (i) removing an oldest sample value and corresponding oldest sample time from the one or more buffers and (ii) subtracting the time period corresponding to the oldest sample time from the time integrator;
- and
- estimating the characteristic by integrating the sample values in the sub-sequence.
A method of estimating a characteristic of a wind turbine electrical signal, the method comprising:
- (i) sampling a wind turbine electrical signal to determine a sample value;
- (ii) buffering the sample value, and a sample time associated with the sample value, at one or more buffer addresses of one or more buffers, the one or more buffer addresses being based on a value of a front counter;
- (iii) adding, to a time integrator, a time period associated with the sample time, the time integrator representing a total of the time periods associated with a sub-sequence of buffered sample values, the sub-sequence being defined by a buffer address based on the value of the front counter and a buffer address based on a value of a rear counter;
- (iv) adjusting a value of the rear counter to adjust a length of the sub-sequence and updating the time integrator in dependence on the adjusted value of the rear counter;
- (v) integrating the sample values in the sub-sequence;
- (vi) incrementing the front counter;
- and
- (vii) repeating steps (i)-(vi);
- wherein time periods associated with sample times associated with the samples values in the sub-sequence are variable.
A system, comprising:
- a wind turbine, comprising:
- a tower;
- a nacelle disposed on the tower;
- a generator disposed in the nacelle;
- a rotor mechanically coupled to the generator and extending from the nacelle;
- a plurality of blades disposed on the rotor;
- and
- an apparatus for estimating a characteristic of an electrical signal from the wind turbine, the apparatus comprising:
- at least one processor;
- and
- a memory operatively coupled to the at least one processor, the memory storing instructions that, when executed, causes the at least one processor to perform an operation, comprising:
- buffering a sequence of sample values of the wind turbine electrical signal;
- buffering a sequence of sample times corresponding with the sequence of sample values, wherein the time periods represented by the sample times are variable;
- determining a sub-sequence of the buffered sample values to integrate by:
- updating a time integrator by adding to a value of the time integrator a time period represented by a sample time of the sequence of sample times;
- and
- until a value of the time integrator is less than or equal to an integration period, repeatedly (i) removing an oldest sample value and corresponding oldest sample time from the one or more buffers and (ii) subtracting the time period corresponding to the oldest sample time from the time integrator;
- and
- estimating the characteristic by integrating the sample values in the sub-sequence.
Dependencies are inferred from the claim text.