
Current control, -limiting and switching frequencies
© KEB, 2012-10
COMBIVERT F5-A, -E, -H
Page 7.10 - 5
7
7.10.3
Switching frequencies and derating
7.10.3.1
Switching frequency (uF.11, In.03, In.04, ru.45)
The desired switching frequency can be selected in parameter uF.11. The higher the switching frequency the
smaller the noise level and the smaller the current ripple and the losses in the motor involved. Simultaneously
the losses in the inverter and also the isolation straining of the motor increase caused by switching edges.
uF.11: Switching frequency
Value
Switching frequency
0
2 kHz
1
4 kHz
2
8 kHz
3
12 kHz
4
16 kHz
The current ripple is a harmonic current which superimposes the sine-wave output current.
It is generated by the clocked output voltage of the frequency inverter. This ripple increases the maximum value
of the current and thus may lead to triggering of the overcurrent error or the hardware current limit, although the
displayed apparent current (ru.15) or utilization value (ru.13) is significant below this limit.
Picture 7.10.3.1 Carrier frequencies
Base frequency of the phase
current
actual current = base frequency
with superimposed ripple
0.0955
0.096
0.0965
0.097
0.0975
0.098
0.0985
0.099
0.0995
-20
-15
-10
-5
0
5
10
15
20
The size of the current ripple is depending on the switching frequency and the motor inductance. The current
ripple is usually insignificant for standard motors with a power < 50kW and a rated switching frequency of the
unit of min. 4 kHz.
The smaller the leakage inductance (ASM) and/or the winding inductance (SM) the higher the ripple. This is
particularly the case for motors with high power or spindle motors. Therefore the carrier frequency must be
selected as high as possible for these motors.
Attention: Generally the switching frequency should be at least 10 times higher than the maximum occurring
output frequency of the inverter.
The maximum switching frequency can be read in parameter In.03. The frequency inverter can be operated
permanently only with its rated carrier frequency (In.04) (independent on temperature and utilization).
Содержание COMBIVERT F5-A
Страница 1: ...KEB COMBIVERT F5 A E H 4 4 APPLICATION MANUAL Mat No Rev 00F5AEA K440 1A...
Страница 2: ...Page 1 1 2 COMBIVERT F5 A E H KEB 2008 02 Table of contents...
Страница 4: ...Page 1 1 4 COMBIVERT F5 A E H KEB 2008 02 Table of contents...
Страница 14: ...Page 1 1 14 COMBIVERT F5 A E H KEB 2008 02 Table of contents...
Страница 20: ...Page 2 1 6 COMBIVERT F5 A E H KEB 2012 10 Product Overview...
Страница 28: ...Page 3 1 8 COMBIVERT F5 A E H KEB 2012 10 Control Units...
Страница 34: ...Page 4 1 6 COMBIVERT F5 A E H KEB 2012 10 Fundamentals...
Страница 40: ...Page 4 2 6 COMBIVERT F5 A E H KEB 2012 10 Password input...
Страница 42: ...Page 5 1 2 COMBIVERT F5 A E H KEB 2012 10 Selection of Operating Mode...
Страница 46: ...Page 5 1 6 COMBIVERT F5 A E H KEB 2012 10 Selection of Operating Mode...
Страница 70: ...Page 6 2 20 COMBIVERT F5 A E H KEB 2012 10 Start up...
Страница 140: ...Page 7 3 44 COMBIVERT F5 A E H KEB 2012 10 Digital in and outputs...
Страница 200: ...Page 7 5 38 COMBIVERT F5 A E H KEB 2012 10 Motor data and controller adjustments of the asynchronous motor...
Страница 207: ...Motor data and controller adjustments of the synchronous motor KEB 2012 10 COMBIVERT F5 A E H Page 7 6 7 7...
Страница 238: ...Page 7 7 12 COMBIVERT F5 A E H KEB 2012 10 Speed control...
Страница 254: ...Page 7 8 16 COMBIVERT F5 A E H KEB 2012 10 Torque display and limiting...
Страница 260: ...Page 7 9 6 COMBIVERT F5 A E H KEB 2012 10 Torque control...
Страница 292: ...Page 7 11 26 COMBIVERT F5 A E H KEB 2012 10 Speed measurement...
Страница 432: ...Page 7 14 14 COMBIVERT F5 A E H KEB 2012 10 Parameter sets...
Страница 466: ...Page 7 15 34 COMBIVERT F5 A E H KEB 2012 10 Special functions...
Страница 478: ...Page 7 16 12 COMBIVERT F5 A E H KEB 2012 10 CP Parameter definition...
Страница 480: ...Page 8 1 2 COMBIVERT F5 A E H KEB 2012 10 Troubleshooting 8 1 1 General 8 1 3 8 1 2 Error Messages and their Cause 8 1 3...
Страница 488: ...Page 8 1 10 COMBIVERT F5 A E H KEB 2012 10 Troubleshooting...
Страница 496: ...Page 9 1 8 COMBIVERT F5 A E H KEB 2012 10 General design...
Страница 538: ...Page 11 1 28 COMBIVERT F5 A E H KEB 2012 10 Parameter...
Страница 540: ...Page 12 1 2 COMBIVERT F5 A E H KEB 2008 02 Annex 12 1 1 Index 12 1 3...