Predictive Control of Three Phase AC/DC Converters

98 CHAPTER 6. EXPERIMENTAL STUDY
(a)
DPC-SVM
(b)
P
u P a
Q
CSF-P-DPC
VF-CSF-P-DPC
Figure 6.8: Experimental transient state of: DPC-SVM, CSF-P-DPC and VF-
CSF-P-DPC, step change of referenced active power P ref from 1 to 2 kW. From
the top: (a) referenced P ref and measured P active powers (500 W/div), and referenced
Q ref and measured Q reactive powers (500 var/div) (b) VSC input voltage
u P a (200 V/div)
Figures 6.9 – 6.10 present second test, which was step change of DC-link
voltage reference value U DCref from 300 V to 600 V. The DC-link voltage PI
controller has been tuned for each method according to the rules presented in
Section 3.4. For all controls U DC overshoot is between 3% – 5%, and regulation
time is between 30 – 40 ms. Note that DC-link controller output has been limited
to 3.5 kW in order to avoid converter shot down caused by over current protection.