Predictive Control of Three Phase AC/DC Converters

74 CHAPTER 4. PREDICTIVE DIRECT POWER CONTROL
650
600
VF-CSF-P-DPC
200
u La i La 20 (b)
(a) U DC
0.24 0.26 0.28 0.3 0.32 0.34
550
ψ La
500
450
0
0
400
350
300
−20
250
0.24 0.26 0.28 0.3 0.32 0.34
−200 0.24 0.26 0.28 0.3 0.32 0.34
500
8000
400
300
200
100
0
7000
6000
5000
4000
P Q
(d)
(c) u P a
0.24 0.25 0.26 0.27 0.28 0.29 0.3 0.31 0.32 0.33
−100
−200
3000
2000
−300
−400
−500
0.24 0.26 0.28 0.3 0.32 0.34
Figure 4.27: Transient operation of VF-CSF-P-DPC, step change of referenced
DC voltage U DCref from 300 V to 600 V: (a) referenced and measured DC voltage
U DC [V], (b) line voltage u La [V], estimated virtual flux ψ La [Wb] and line
current i La [A], (c) VSC input voltage u P a [V], (d) referenced and measured
active P [W]and reactive power Q [var]
1000
0
4.9 Summary
Principles of Model Predictive Control with Finite control Sets (FS-MPC) as well
as Virtual Flux approach for CSF-P-DPC have been presented in this Chapter.
In view of switching frequency, control methods have been divided into variable
(VSF) and constant switching frequency (CSF) approaches.
Control Method t set [µs] t r [µs]
VSF-P-DPC 300 125
HC-VSF-P-DPC 300 125
FL-VSF-P-DPC 300 200
CSF-P-DPC 300 250
VF-CSF-P-DPC 300 250
Table 4.8: Dynamic properties of P-DPC methods for P ref step change
The VSF based methods have following advantages: