Predictive Control of Three Phase AC/DC Converters

48 CHAPTER 4. PREDICTIVE DIRECT POWER CONTROL
0
(a)
Bode Diagram
From: Input Point1 To: Output Point1
−50
−100
Magnitude (dB)
−150
−200
System: Band Stop Filter
I/O: Input to Output
Frequency (Hz): 4.02e+003
Magnitude (dB): −266
−250
−300
0
−45
−90
−135
Phase (deg)
−180
−225
System: Band Stop Filter
I/O: Input to Output
Frequency (Hz): 4.02e+003
Phase (deg): −181
−270
−315
−360
10 2 10 3 10 4
Frequency (Hz)
0
(b)
Bode Diagram
From: Input Point To: Output Point
−50
−100
Magnitude (dB)
−150
−200
−250
System: Band Pass Filter
I/O: Input to Output
Frequency (Hz): 4e+003
Magnitude (dB): −0.022
−300
−350
180
135
Phase (deg)
90
45
0
−45
System: Band Pass Filter
I/O: Input to Output
Frequency (Hz): 4e+003
Phase (deg): 2.61
−90
−135
−180
10 2 10 3 10 4
Frequency (Hz)
Figure 4.5: Bode diagrams of cost function digital filters: (a) band stop filter
4 kHz, (b) band pass filter 4 kHz
errors defined as:
P err = P ref − P P (4.19)
Q err = Q ref − Q P (4.20)
However, additional K F BP factor has to be set up individually for different
frequencies what is major drawback of this method. Also, it is difficult to use
it for low frequencies removal, because filter pass band window has to be very
narrow, which leads to high order of the designed filter.