Information Technology Reference
In-Depth Information
1.2
1
0.8
0.6
K
e
=1.5562;K
d
=5.1256;
ʱ
=4.2115;
ʲ
=30.2011
0.4
K
e
=1.5200;K
d
=9.0011;
ʱ
=6.2364;
ʲ
=29.2500
K
e
=1.0000;K
d
=9.0600;
=3.1107;
=42.7888
ʱ
ʲ
0.2
K
e
=1.2550;K
d
=8.3340;
ʱ
=2.0012;
ʲ
=48.0100
0
0
0.5
1
1.5
2
2.5
Time (sec)
Fig. 10 Step responses of the PSO-tuned PID-type fuzzy controlled system: ISE criterion case
4.4 Experimental Results
In order to illustrate the ef
ciency of the proposed metaheuristics-tuned PID-type
fuzzy control structure, we try to implement the controller within a real-time
framework. The developed real-time application acquires input data, speed of the
DC drive, and generates control signal for thyristors of AC-DC power converter as
a PWM signal (Hagg
ge et al.
2009
). This is achieved using a digital control system
based on a PC computer and a PCI-1710 multi-functions data acquisition board
which is compatible with MATLAB/Simulink as described in Fig.
11
.
The power part of the controlled process is constituted of the single-phase bridge
recti
è
er,
constituted by two thyristors and two diodes. The presence of thyristors makes the
average output voltage controllable. A thyristor can be triggered by the application
of a positive gate voltage and hence a gate current supplied from a gate drive
circuit. The control voltage is generated with the help of a gate drive circuit, which
is called a
er converter. Figure
11
shows the considered half-controlled bridge recti
firing or triggering circuit. The used bridge thyristors are switched ON by
a train of high-frequency impulses.
In order to obtain an impulse train, beginning with a
fixed delay after the AC
supply source zero-crossing, it is necessary to generate a sawtooth signal, syn-
chronized with this zero-crossing. This is achieved using a capacitor charged with a
constant current during the 10 ms half period of the AC source, and abruptly
discharged at every zero-crossing instant. The constant current is obtained using a
BC547 bipolar transistor whose base voltage is maintained constant due to a
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