V/F Control Or Speed Control - Siemens Sinamics G110M Getting Started

When a control command is received at the respective digital input, the motor rotates at
±150 rpm. The same ramp-up and ramp-down times as described above apply.
Image 4-6
4.4

V/f control or speed control

For induction motors, there are two different open-loop control or closed-loop control
techniques:
● V/f control (calculation of the motor voltage using a characteristic curve)
● Closed-loop speed control (also: field-oriented control or vector control)
Criteria for selecting either V/f control or speed control
In many applications, the V/f control suffices to change the speed of induction motors.
Examples of typical applications for V/f control include:
● Pumps
● Fans
● Compressors
● Horizontal conveyors
When compared to V/f control, vector control offers the following advantages:
● The speed is more stable for motor load changes.
● Shorter accelerating times when the setpoint changes.
● Acceleration and braking are possible with an adjustable maximum torque.
● Improved protection of the motor and the driven machine as a result of the adjustable
torque limiting.
● Torque control is only possible with vector control.
Examples of typical applications in which speed control is used:
● Hoisting gear and vertical conveyors
● Winders
● Extruders
Distributed converter for SIMOGEAR geared motors
Getting Started, 01/2016, FW V4.7.6, A5E36100338B AD
Jogging the motor with the factory settings
Commissioning
4.4 V/f control or speed control
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