Control method and system for wind turbine

Patent metadata

Field	Value
Publication number	US-9976539-B2
Application number	US-201514732862-A
Country	US
Kind code	B2
Filing date	Jun 8, 2015
Priority date	Jun 11, 2014
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A control method and a control system for a wind turbine are disclosed. The control method comprises measuring wind turbine blade pitch angles; obtaining a wind turbine rotor acceleration value; determining whether a blade pitch runaway fault condition is occurring; and during the blade pitch runaway fault condition, adjusting a pitch angle command based at least in part on the rotor acceleration value, a pitch angle of at least one faulted blade and a pitch angle of a healthy blade; and controlling wind turbine blades based at least in part on the adjusted pitch angle command.

First claim

What is claimed is:

1. A control method comprising:
measuring wind turbine blade pitch angles;
obtaining a wind turbine rotor acceleration value;
determining whether a blade pitch runaway fault condition is occurring; and
during the blade pitch runaway fault condition,
adjusting a pitch angle command based at least in part on the wind turbine rotor acceleration value, a pitch angle of at least one faulted blade and a pitch angle of a healthy blade, wherein adjusting the pitch angle command comprises:
generating a first pitch angle rate command based at least in part on a difference between the pitch angle of the at least one faulted blade and the pitch angle of the healthy blade;
generating a second pitch angle rate command based at least in part on the wind turbine rotor acceleration value;
summing the first pitch angle rate command and the second pitch angle rate command; and
integrating the summed pitch angle rate command; and

controlling wind turbine blades based at least in part on the adjusted pitch angle command.

2. The control method of claim 1 , wherein the pitch angle of the healthy blade comprises a pitch angle command for normal operation or a pitch angle measurement of the healthy blade.

3. The control method of claim 1 , wherein the first pitch angle rate command is calculated by the following equation,
{dot over (θ)} sync [n ]=max{(θ c [n− 1]−θ f [n ])÷Δ T, 0}

wherein:
{dot over (θ)} sync represents the first pitch angle rate command,
θ c represents the pitch angle of the healthy blade,
θ f represents the pitch angle of the at least one faulted blade,
n represents a sampling time, and
ΔT represents a sampling time interval.

4. The control method of claim 3 , wherein when at least two blades comprise faulted blades, the pitch angle of the at least one faulted blade comprises an average pitch angle of the faulted blades.

5. The control method of claim 1 , further comprising:
generating the second pitch angle rate command based on the wind turbine rotor acceleration value in conjunction with a saturation arithmetic with a rotor acceleration upper limit and no lower limit.

6. The control method of claim 5 , wherein the second pitch angle rate command is calculated by the following equation,

θ
.

ω
.

r

=

(

∂

Mz
aero

∂

θ
1

+
…
+

∂

Mz
aero

∂

θ
m

)

-
1

⁢

(

-

∂

Mz
aero

∂

ω
r

⁢

ω
.

r

+

K
1

⁡

(

ω
.

r
,
ref

-

ω
.

r

)

)

⁢

ω
.

r
,
ref

=

[

ω
.

r
,
max

,

-
∞

)

wherein:
{dot over (θ)} {dot over (ω)} r represents the second pitch angle rate command,

∂

Mz
aero

∂

θ
m

represents a partial derivative of rotational moment on the blade pitch angle,
m represents a number of the blades,
ω r represents an angular velocity of the rotor,

∂

Mz
aero

∂

ω
r

represents a partial derivative of rotational moment on the angular

Assignees

• Gen Electric

Inventors

• Daher Adegas Fabiano
• Huang Xiongzhe
• Agarwal Pranav

Classifications

• Y02E10/728

  Onshore wind turbines · CPC title

• Y02E10/723

  Cross-Sectional Technologies · mapped topic

• F03D13/20 Primary

  Arrangements for mounting or supporting wind motors; Masts or towers for wind motors · CPC title

• F03D7/0224

  Adjusting blade pitch · CPC title

• F03D17/00

  Monitoring or testing of wind motors, e.g. diagnostics (testing during commissioning of wind motors F03D13/30) · CPC title