Environmental Engineering Reference
In-Depth Information
1.1
1.1
1.1
1
1
1
0.9
0.9
0.9
0.8
0.8
0.8
EC1 EC2 EC3 EC4 EC5
EC1 EC2 EC3 EC4 EC5
EC1 EC2 EC3 EC4 EC5
1.1
1.1
1.1
1
1
1
0.9
0.9
0.9
0.8
0.8
0.8
EC1 EC2 EC3 EC4 EC5
EC1 EC2 EC3 EC4 EC5
EC1 EC2 EC3 EC4 EC5
M1
M2
M3
M4
Fig. 11.13 Fault: blade pitch sensor gain. Normalized RMS (NRMS) of generator power error,
blade pitch rates and platform motions. Platform motion is hardly affected by this fault
(M1 and M2). This effect is clear by the increased tower torsional and LSS DEL
indices. The slow performance of the actuator increases the rotor imbalance due to
the late response of the faulty blade compared to the others (Fig.
11.14
). However,
the slow performance of the pitch system does not affect power production;
moreover, its effects on platform motion are marginal. On the other side, the slow
performance decreases the faulty blade pitch rate and introduces small increase to
the rate of the healthy blades as they try to compensate for the slow behavior of the
faulty one. The slow pitch system also works as a low-pass filter as it cannot
respond to the high frequency measurement noise as the healthy blades do which is
clear from Fig.
11.15
.
1.3
1.3
1.3
1.2
1.2
1.2
1.1
1.1
1.1
1
1
1
0.9
0.9
0.9
0.8
0.8
0.8
EC1 EC2 EC3 EC4 EC5
EC1 EC2 EC3 EC4 EC5
EC1 EC2 EC3 EC4 EC5
M1
M2
M3
Fig. 11.14
Fault:
actuator
performance
degradation.
Normalized
DEL
(NDEL)
of
tower
torsional and LSS moments
