Environmental Engineering Reference
In-Depth Information
0.3%
Hub
1.1%
Drive train
1.2%
Mechanical brakes
Structure
1.5%
Entire unit
2.7%
Generator
5.5%
Yaw system
6.7%
9.8%
Gears
12.9%
Control system
13.3%
Hydraulics
Blades
13.4%
Sensors
14.1%
Electric system
17.5%
0.0%
2.0%
4.0%
6.0%
8.0%
10 .0% 12 .0% 14 .0% 16 .0% 18 .0% 20 .0%
Fig. 7.1
Distribution of number of failure for Swedish wind power plants [
35
]
For example, the wind turbine benchmark in [
29
,
30
] involves rotor and generator
speed parameter scaling and stuck sensor faults. These faults have a direct effect
on the reference torque signal provided by the controller. Consequently, the
controller will start to drive the wind turbine away from its optimal operation,
which in turn leads to lower conversion efficiency or may even prevent the turbine
from converting energy (cutoff).
This chapter focuses on investigations of different aspects related to a fault
tolerant control approach to sustainable wind turbine systems, as well as the
presentation of FTC strategies for OWTs based on the T-S fuzzy framework.
A typical non-linear state space model of a wind turbine system is described and a
T-S fuzzy model of this system is also presented. The investigations are based on
a 4.8 MW benchmark model proposed by [
29
,
30
].
7.2 Structure and Approaches to FTC Systems
Generally, the nominal controller (sometimes referred to as the 'baseline' con-
troller, see [
32
]) aims to stabilise and achieve the required closed-loop perfor-
mance during normal operating conditions. To give the controlled system the
ability to tolerate fault effects, additional inherent ability of the controller and/or
extra assistant blocks should be inserted in the control loop. Figure
7.2
illustrates
the main structure of the fault tolerant system.
Generally, two steps are required to provide the system with the capability to
tolerate faults:
• Equip the system with some mechanism to make it able to detect the fault once
it occurs, provide information about the location, identification of faulty
component and decide the required remedial action in order to maintain
acceptable operation performance (Supervision level).
