Siemens SINAMICS S120 Function Manual page 92

Operating Modes
Servo control
Structure of V/f control
n*
Ramp-function
generator
p1318 p0314
Fig. 3-15 Structure of V/f control
Prerequisites for V/f control
1. Initial commissioning has been performed:
The parameters for V/f control have been initialized with appropriate values.
2. Initial commissioning has not been performed:
The following relevant motor data must be checked and corrected:
– r0313
– p0314
– p1318
– p1319
– p1326
– p1327
V/f control can now be commissioned.
Note
With synchronous motors, V/f mode is normally only stable at low speeds. Higher
speeds can induce vibrations.
Commissioning V/f control
1. Verify the preconditions for V/f control mode.
2. Set p0311 ––> rated motor speed
3. Set p1300 = 0 ––> activates the function
4. Activate the enable signals for operation
5. Specify the speed setpoint ––> evaluate the diagnostic function
3-92
p1317 = 1
p1327
p1319
Motor pole pair number, actual (or calculated)
Motor pole pair number
V/f control ramp-up/ramp-down time
V/f control voltage at zero frequency
V/f control programmable characteristic frequency 4
V/f control programmable characteristic voltage 4
Drive converter
f*
U*
p1326
© Siemens AG 2006 All Rights Reserved
SINAMICS S120 Function Manual, 03/2006 Edition
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