50
7VV3002 must be implemented on the infeed side of the current converter. Siemens
technical advisers will support you with configuration.
More at:
http://support.automation.siemens.com/WW/view/en/19338566
Direct-voltage-side overvoltage protection, SIOV, or 7VV3003...
If a direct current motor is used as the load, no overvoltage protection is required on the
direct voltage output to protect the converter.
If a high load inductance occurs, for example, when feeding a motor field or a solenoid with a
6-pulse converter (output of armature voltage output terminals of 6RA80), overvoltage
protection parallel to the direct voltage output is always required. This must be configured for
the given current and induction of the load.
Converter transformer:
In the case of higher power converters, a separate converter transformer is recommended
(connection on high voltage side at the medium voltage level), to prevent overloading and/or
damage of weak system consumers by system perturbation from the converter(s)
(commutation notches, harmonics).
The transformer apparent power is:
S
T
= Unetwork* 1.35 * 1.05 * Id
S
T
: Required apparent power of transformer, Unetwork: Line-to-line network voltage at
converter input; Id: Direct Current
Converter Commutation Protector, CCP:
The additional component CCP is available from Siemens for protection against the effects of
conduction-through.
http://support.automation.siemens.com/WW/view/en/21688372
This CCP can be used with 6RA80 with a nominal direct current (actual value acc. to
r50072[1]) from 300 to 2000 A (if 6RA80 is connected in parallel, use, CCPs in parallel) and
nominal line voltages from 400 to 690 V.
Siemens technical advisers will support you with configuration.
Conduction-through is a physical effect of the line-commutated converter and is an effect that
can occur during braking operation (regenerative feedback, 4Q or 2Q with field reversal) with
a blown fuse.
See also the detailed article in the Internet, at the following address:
http://support.automation.siemens.com/WW/view/en/24120447
High-speed DC circuit-breaker:
Besides the CCP, implementation of a high-speed DC circuit-breaker is the only way of
protecting the converter against the effects of conduction-through. The CCP is the preferred
solution for new systems if the given current and voltage range is adequate. Older systems
being retrofitted frequently have a high-speed DC circuit-breaker. We recommend keeping
this. The high-speed circuit-breaker should trigger a fault during a current rise in order to
prevent a fuse blowing. An air smoothing reactor is usually required in the direct current
circuit to limit the rate of rise of the current on a fault. The required induction of the reactor
depends on the system size and the type of semi-conductor protective fuse used. When
retrofitting the old converter with 6RA80, check the design of these reactors; Siemens
advisory services will help you with this.
Main contactor in the 6RA80 infeed:
This is dimensioned for maximum current I
AC
for AC1 operation.
I
AC
= 0.816 * Id
max
. Id
max
= maximum operational direct current. See Catalog LV1.
