Siemens SINAMICS DCM Operating Instructions Manual page 622

Descriptions of functions
10.32 Diagnostics
Sequence of simulation mode
1. Selection of an individual thyristor with p51840.
This results in the activation of simulation mode. However, this only happens in operating
states ≥ o7.0. This means that during simulation mode the line contactor is opened and
the power unit is not under voltage load.
In all other operating states, p51840 is ineffective.
If simulation mode is active, every 20 ms it outputs two firing pulses with intervals of
3.33 ms to the selected thyristor. The length setting of the pulse packet with p50079
(short pulse/long pulse) is considered here.
While simulation mode is active, the DCM switches to operating state o8.1. As such, an
ON command is ineffective during simulation mode.
2. Measurement of the firing current on the gate connection of the selected thyristor using
current probe and oscilloscope.
3. End simulation mode with p51840 = 0.
By successively testing all thyristors, the following checks are possible:
● Correctness of wiring on firing pulse cables
● Correctness of set firing pulse chopping (see p51826)
● Correctness of firing current of the thyristors
Remarks on simulation mode
● Remark 1:
Simulation mode is in principle also possible for a DCM DC Converter. However, there is
no need for this there, as the corresponding tests have already been performed at the
manufacturer's factory. Furthermore, the firing pulse cables are not accessible without
impermissible intervention (opening cable ties).
● Remark 2:
The thyristor diagnostics described in Chapter "Thyristor diagnostics (Page 595)" are not
suitable for checking the electrical system following mounting. In the case of thyristor
diagnostics, the line voltage must be present at the power unit. The wiring of the firing
pulse cables is assumed to be correct.
Thyristor diagnostics are intended to support troubleshooting in the case of unexplained
fault messages or blown fuses which suggest the presence of defective thyristors
(F60004, F60010, F60057, F60300, etc.).
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SINAMICS DCM Control Module
Operating Instructions, 12/2018, A5E34888669A