Cell Section - Siemens SINAMICS PERFECT HARMONY GH180 Operating Instructions Manual

Description
4.1 Cabinet Details
Depending upon order specifications, the transformer is configured for 30 or 42-48 pulse power
quality by using extended delta 750 V secondary windings.
The transformer is a dry type forced air-cooled unit, and polyglass air baffles are used to direct
air movement across the coils. All SINAMICS PERFECT HARMONY GH180 transformers are
thermally monitored.
All connections to and from the transformer are made with insulated wire. The transformer is
equipped with off-line taps to accommodate utility line variations, +5%, 0%, and -5% are
supplied on typical units.
Dependent upon order specifications, the winding conductor material may be aluminum or
copper.
The transformers are appropriately sized for the application. However, other factors such as
motor lead length, motor service factor, environment conditions, ambient conditions, altitude,
and power cell redundancy must be considered.
4.1.4

Cell Section

The basic electrical diagrams for all SINAMICS PERFECT HARMONY GH180 systems are
similar. One of the most critical components of the drives is the power cell. The cell voltage
is 750 V. Depending on the operating load voltage, 15, 21, or 24 cells are used to develop the
multi-level PWM output waveform varies.
Each power cell input side is configured as a 6-pulse diode rectifier. Terminals are supplied
with power via a secondary winding of the transformer. The DC output of the rectifier is filtered
via the capacitor bank and supplies power to a single-phase inverter on the output side. Output
terminals of each cell are connected in series in each phase group.
Note
Discharging the DC Link
The power cells include discharge resistors to dissipate stored energy after the input voltage
is removed. The power cell DC bus voltage decays to less than 50 VDC in less than 10 minutes.
Fuses
The secondary of the transformer is routinely fused. The fuses are mounted externally on the
front panel of the power cells (located in the cell section). Only two phases of each transformer
secondary (power cell input) are fused. Fuses are forced air-cooled for longer life and less
thermal stress.
Note
Permitted Mixture of Fuse Vendors
A mixture of fuse vendors is permitted, but not within the same power cell (i.e., FA1A and FA1C
should be from the same vendor).
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Operating Instructions, 07/2018, A5E42736645A_AB
Air Cooled 6SR5