
PROGRAMMING
INSTRUCTIONS
SINUS PENTA
249/452
31.
CARRIER
FREQUENCY
MENU
3 1.1.
Overview
The Carrier Frequency Menu sets some of the PWM modulation characteristics based on the preset type of control.
31.1.1.
IFD
C
O NTRO L A ND
VTC
C
O NTRO L
The IFD and VTC control algorithms allow gaining access to all the parameters included in the Carrier Frequency
menu.
The user can set the minimum value and the maximum value of the switching carrier frequency and the number of
pulses per period used to produce the output frequency when switching from min. carrier frequency to max. carrier
frequency (synchronous modulation).
The silent modulation function can also be enabled (
C004
).
31.1.2.
E
X AMP LE
(IFD
A ND
VTC)
Setting two levels of carrier frequency and the number of pulses used for synchronous modulation.
A lower value for carrier frequency ensures a better performance of the motor but implies higher noise levels. Suppose
that the connected motor has a rated speed equal to 1500rpm at 50Hz and that you need the best performance up to
200rpm and a “noiseless” carrier frequency at max. speed (3000rpm).
In this case, the max. speed of the drive will produce an output voltage with a frequency value equal to 100Hz; in
proximity to this speed the carrier frequency should be at its maximum level. Suppose that a model implementing max.
16kHz carrier frequency is used.
Assign the following:
C001
= 1600Hz
C002
= 16000Hz
C003
(
C002
/100Hz) = (160 pulses per period)
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
0
10
20
30
40
50
60
70
80
90 100
fout ( Hz )
fcarrier
( Hz )
C002
C001
(C001 / C003)
(C002 / C003)
Figure 40: Carrier frequency (example).
Suppose that
C003
= 192np, so that
C002
/
C003
= 16000/192 = 83.33Hz. The max. carrier frequency is obtained with
this output frequency. The min. frequency is kept constant until frequency
C001
/
C003
= 8.33 Hz is attained,
corresponding to 250 rpm of the motor speed. In the output frequency range, ranging from 8.33 to 83.33Hz,
synchronous modulation is obtained and the carrier frequency applied results from: f carrier = fout *
C003
[Hz].
Содержание SINUS PENTA
Страница 142: ...SINUS PENTA PROGRAMMING INSTRUCTIONS 142 452 Figure 21 Curve voltage speed implemented by AO1 Example 5 ...
Страница 184: ...SINUS PENTA PROGRAMMING INSTRUCTIONS 184 452 Figure 33 ANALOG Mode Figure 34 DOUBLE DIGITAL Mode ...
Страница 185: ...PROGRAMMING INSTRUCTIONS SINUS PENTA 185 452 Figure 35 General structure of the parameterization of a digital output ...
Страница 348: ...SINUS PENTA PROGRAMMING INSTRUCTIONS 348 452 Figure 57 Power Down Example ...
Страница 435: ...PROGRAMMING INSTRUCTIONS SINUS PENTA 435 452 ...