Integrated Voltage Protection - Siemens SINAMICS S120 Function Manual

6.10

Integrated voltage protection

Description
The speed range of permanent-field synchronous motors (e.g. 1FE1 spindles) can be greatly
extended by means of field weakening.
If faults that hinder controlled operation occur in this operating status, the EMF
(electromotive force) can result in high terminal voltages. These excessively high voltages
must not be applied to the Motor Module because otherwise this could damage all the
components connected to the DC link.
The DC link group can be protected by feeding the motor energy back to the supply system
and tripping the integrated voltage protection mechanism in the Motor Module. If a ground
fault occurs, a Braking Module with a suitable braking resistor can prevent the DC link
voltage from rising until the pre-charging relay of the infeed module is open. The voltage
protection mechanism in the Motor Module is then applied.
Integrated voltage protection is implemented by shorting the motor cables in the power unit
(Motor Module) (internal armature short-circuit).
This eliminates the need for a VPM (Voltage Protection Module) for 1FE motors (e.g. VPM
120 or VPM 200).
The integrated voltage protection is activated with p1231 = 3. It is initiated when the pulses
are canceled.
To ensure that the motor functions properly in the event of a power failure, an external 24 V
supply (USV) must be used for the components.
If the Motor Module supports integrated voltage protection (r0192.10=1), the Motor Module
decides on the basis of the DC link voltage whether or not the internal armature short-circuit
is applied. In this case, the voltage protection remains operative even if the DRIVE-CLiQ
connection between the Control Unit and the Motor Module is interrupted. To ensure
continued operation of the components in the drive line-up after a mains power failure, 24 V
is supplied from the DC link via a Control Supply Module (CSM).
The IVP (Internal Voltage Protection) mechanism ensures a stable 24 V supply.
The DC link voltage is monitored independently in the Motor Module.
If the DC link voltage exceeds 820 V, the internal armature short-circuit is activated.
If the DC link voltage drops below 450 V, the internal armature short-circuit is deactivated
again. This ensures that the necessary input voltage for the Control Supply Module is
maintained.
Note
The "Integrated voltage protection" (IVP) function can be used only on Motor Modules in
booksize and booksize compact format.
Suitable booksize modules can be identified by the number 3 at the end of the order number
e.g. 6SL3130-6TE21-6AA3. The booksize Compact modules are universally usable.
Drive functions
Function Manual, (FH1), 10/2008, 6SL3097-2AB00-0BP5
Basic functions
6.10 Integrated voltage protection
217