Approximation of Optimized Fuzzy Logic Controller for Shunt Active Power Filter - Complex System Modelling and Control Through Intelligent Soft Computations - page 580

Load Current (Phase A)

20

0

-20

Source Current (Phase A)

40

20

0

-20

-40

Filter Current (Phase A)

10

0

-10

DC Link Voltage & Ref. Voltage

700

680

660

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65

Time (sec)

Fig. 19 Dynamic response of shunt APF with 4-rule approximated FLC using Gaussian MFs

Table 5 Dynamic response of shunt APF controlled by 49-rule FLC and approximated FLC using
Gaussian MFs
Load

% peak overshoot/under-shoot Settling time (cycles)

49-rule
FLC

Approximated
4-rule FLC

49-rule
FLC

Approximated
4-rule FLC

Case-1 0.51 0.53 0.92 0.95

Case-2 2.29 2.33 1.86 1.90

Case-3 1.32 1.34 0.42 0.44

time, are comparable with that of a 49-rule FLC and hence con rm the effectiveness

of proposed approximation methodology.
The comparison of THD pro le of source current with proposed approximated

FLC and 49-rule FLC using Gaussian MFs is shown in Fig. 20 . The harmonic
compensation performance of proposed scheme is at par with 49-rule FLC and even
better at the instant of load change.