Method of automatically calculating power curve limit for power curve monitoring of wind turbine

Patent metadata

Field	Value
Publication number	US-9664176-B2
Application number	US-201314418922-A
Country	US
Kind code	B2
Filing date	Mar 8, 2013
Priority date	Sep 18, 2012
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

The present invention provides a method of automatically calculating a power curve limit for the power curve monitoring of a wind turbine that may set an optimal power curve limit by automatically calculating a power curve limit for power curve monitoring even if wind speed-power data measured at a wind turbine includes a large amount of abnormal data in addition to normal data. To this end, the present invention includes: classifying, by an input data classifying unit, the input data on wind power generation through a variable speed bin; calculating, by a power calculating unit, a power average value and standard deviation for each bin for the classified input data; estimating, by a power curve estimating unit, a power curve for the calculated power average value for each bin; searching for, by a limit searching unit, an accurate power curve limit while moving the estimated power curve; and setting, by a data extracting unit, the data included in the accurate power curve limit as new input data.

First claim

The invention claimed is:

1. A method of automatically calculating power curve limits for power curve monitoring of a wind turbine, comprising:
a first operation of classifying input data of wind power generation through variable speed bins by an input data classification unit;
a second operation of calculating a first mean value and a standard deviation of power for each bin for the classified input data by a power calculation unit;
a third operation of estimating a power curve for the first mean value of power for each bin by a power curve estimation unit;
a fourth operation of searching for accurate power curve limits while shifting the estimated power curve by a limit search unit; and
a fifth operation of setting the input data between the accurate power curve limits as new input data by a data extraction unit.

2. The method according to claim 1 , wherein the input data classification unit determines wind speed-power data of the input data based on the variable speed bins according to a bin width given by equation below:
Bin Width=1/Number of repetition of entire algorithm loop (m/sec),
wherein the entire algorithm loop includes the first to fifth operations.

3. The method according to claim 1 , wherein the power curve estimation unit estimates the power curve using interpolation, based on the first mean value of power for each bin as an input for the interpolation.

4. The method according to claim 3 , wherein the interpolation is cubic B-spline interpolation.

5. The method according to claim 1 , wherein the limit search unit searches for the accurate power curve limits while shifting the power curve leftwards and rightwards or upwards and downwards.

6. The method according to claim 5 , wherein the limit search unit repeatedly shifts the power curve leftwards and rightwards by a distance of a preset velocity until the following inequality is satisfied:
PDL i −PDL i−1 <β shift ( i >1),

wherein i is the number of repetitions of a limit search algorithm, βshift is a constant for determining whether optimal upper and lower power curve limits are determined at a present stage, and PDL has units of %, and
wherein PDL is defined by equation below:

PDL
i

=

[

⁢

⁢

Number
⁢

⁢
of
⁢

⁢
data
⁢

⁢
present
⁢

⁢
between
⁢

⁢
upper

and
⁢

⁢
lower
⁢

⁢
power
⁢

⁢
curve
⁢

⁢
limits

Total
⁢

⁢
number
⁢

⁢
of
⁢

⁢
input
⁢

⁢
data

×
100

]

i

.

7. The method according to claim 5 , wherein the limit search unit repeatedly shifts the power curve upwards and downwards by a distance of preset power until the following inequality is satisfied:
PDL i −PDL i−1 <γ offset ( i >1)

where i is the number of repetitions of a limit search algorithm, PDL has units of %, and γ shift is a constant for determining whether accurate upper and lower power curve limits are determined, and
wherein PDL is defined by equation below:

PDL
i

=

[

⁢

⁢

Number
⁢

Assignees

• Korea Electric Power Corp

Inventors

• Park Joon Young
• Lee Jun Shin
• Lee Jae Kyung
• Oh Ki Yong
• Park Byoung Mok
• Kang Keum Seok
• Ryu Moo Sung
• Kim Seok Tae
• Kim Ji Young

Classifications

• G06Q50/10 Primary

  Services · CPC title

• F03D7/02 Primary

  the wind motors having rotation axis substantially parallel to the air flow entering the rotor · CPC title

• F03D7/0224 Primary

  Adjusting blade pitch · CPC title

• F03D80/40

  Ice detection; De-icing means · CPC title

• F03D7/00 Primary

  Controlling wind motors  (supplying or distributing electrical power H02J, e.g. arrangements for adjusting, eliminating or compensating reactive power in networks H02J3/18; controlling electric generators H02P, e.g. arrangements for controlling electric generators for the purpose of obtaining a desired output H02P9/00) · CPC title