Voltage Sensing Module - Siemens SINAMICS S120 Function Manual

5.19

Voltage Sensing Module

The Voltage Sensing Module (VSM) is required in the Vector Control and in V/f control for
following functions:
● Synchronizing
Using the "synchronizing" function, the system is synchronized to a line supply. For
example, after synchronization the motor is directly switched over to the line supply
(bypass). Another application is the temporary operation of the motor on the line supply to
allow the converter to be maintained without shutting down the plant or system.
For p3800 = 1, the voltage is sensed using a VSM, which is assigned to the line phases
and a Motor Module (via DRIVE-CLiQ).
● Flying restart
After power ON, the "flying restart" function automatically connects a Motor Module to a
motor which may already be turning. In operation without an encoder, a search is carried
out initially for the motor speed.
For this function, a Voltage Sensing Module (VSM) is required for permanent-magnet
synchronous motors (for additional information, see SINAMICS S120 Control Units
Manual and SINAMICS S120/S150 List Manual in parameter p1200).
A VSM can be used for induction motors in order to reduce the duration of the search
(see Chapter "Fast flying restart (Page 273)").
If only one VSM exists, it is used to acquire the motor voltages when "synchronize" is
deactivated (p3800 = 0).
Topology view
The VSM is used on the encoder side for SINAMICS S120 drives. The VSM is only used at
the VECTOR drive object in sensorless operating modes. The VSM is integrated into the
topology at the position of the motor encoder.
VSM commissioning using STARTER
The VSM for the VECTOR drive object is selected in STARTER using the drive wizard. As
the VSM is not assigned to the encoder data sets (EDS), it cannot be selected on the
encoder side. The component number of the VSM from the current topology must be entered
in parameter p0151[0...1]. This parameter assigns the VSM data set to a VSM evaluation
routine. With parameter p0155[0...n] "Activate/deactivate Voltage Sensing Module", it is
possible to activate or deactivate the VSM explicitly as a topology component.
VSM parameters are independent of the SINAMICS data set model. A maximum of two
VSMs are permitted for each VECTOR drive object.
Note
Using two VSMs
If 2 VSMs are connected to one Motor Module, the 1st VSM (p0151[0]) is used to measure
the line voltage (p3801). The motor voltage is measured (p1200) with the 2nd VSM.
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Vector control
5.19 Voltage Sensing Module
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