Environmental Engineering Reference
In-Depth Information
Fig. 10.9 Residual vectors
r
i
ð
k
Þ
a for stator voltages
b for stator currents
(a)
0.04
0.02
0
−0.02
−0.04
0
2
4
6
8
1
0
0.04
r
2
,
1
0.02
0
−0.02
r
2
,
2
−0.04
0
2
4
6
8
1
0
0.04
r
3
,
1
0.02
0
−0.02
r
3
,
2
−0.04
0
2
4
6
8
10
time [s]
(b)
0.1
r
4
,
2
0.05
0
−0.05
r
4
,
1
−0.1
0
2
4
6
8
1
0
0.1
r
5
,
2
0.05
0
−0.05
r
5
,
1
−0.1
0
2
4
6
8
1
0
0.1
0.05
0
−0.05
−0.1
0
2
4
6
8
10
time [s]
Simulations with fault magnitudes of 2, 3, 5, 8 % for the stator voltages, 5, 8,
10, 15 % for the stator currents have been performed. In all the cases, the decision
algorithm was able to detect and isolate all the faults, with a detection/isolation
delay lower than the required one. We can conclude that, with the proposed sensor
FDI system based on the model of the three-phase signals, sensor FDI for the stator
voltages and currents can be achieved. The performance is not affected by either
changes in the references or in the disturbance, or by faults in the rotor currents.
Faults in the rotor currents are compensated by the control algorithm; so the
effect of the fault in the signals is not noticeable as in the case of faults affecting
the stator voltages and the stator currents. This is shown in Fig.
10.11
.
Figure
10.11
a depicts the measured stator and rotor currents when the fault in
sensor i
s
;
c
(
' ¼
6) is present between t
¼
8
:
5 s and t
¼
9
:
5 s, while Fig.
10.11
b
presents both currents when the fault in sensor i
r
;
b
is present between t
¼
1 s and
t
¼
2 s. Notice in Fig.
10.11
a that the measurement of i
s
;
c
presents a change in
its mean, and that the fault does not produce significative changes in the mean
