Rockwell Automation SB3000 AC Power Modules - Manual (Page 13)

Power Module Description 2-1
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HAPTER
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Power Module Description
This chapter provides an overview the Power Module’s main components and their
mechanical and electrical characteristics. Refer to Appendix B for a block diagram of
the Power Module. The SB3000 theory of operation is described in Appendix C.
2.1 Mechanical Description
High Power SB3000 Power Modules are housed in protective sheet metal enclosures,
as shown in figures 2.2 to 2.4. The Power Modules come in single, double, and triple
bay cabinet configurations, depending upon the current rating. See figures 3.1 to 3.3
for Power Module dimensions.
The Power Modules have the following main components:
Phase modules
Each Phase module contains four semiconductor IGBTs (insulated gate bi-polar
transistors). IGBT pairs are switched on and off by the integrated Snubber/Gate Driver
module to provide regulated DC output voltage. Fuses and thermostats are provided
to protect the IGBT modules.
Snubber/Gate Driver Module
Each Snubber/Gate Driver module receives gating signals via fiber-optic cabling from
the GDI module(s) in the PMI rack and translates the signals into the appropriate
voltage and current levels to turn the IGBTs on and off. Feedback, indicating the
integrity of the module and IGBTs, is then sent back to the GDI module(s).
This module also provides snubber circuitry, resistors, diodes, and capacitors, to
control voltage transients produced when the IGBTs are switching.
Fiber-Optic Communication
Fiber-optic cabling is used to transmit gate driver signals from the Gate Driver
Interface (GDI) module.These signals are used to turn the IGBTs on and off. IGBT
module feedback status information is sent via the fiber-optic cabling back to the GDI
module(s) in the PMI rack. Fiber-optic cabling is immune to electromagnetic and radio
frequency interference (EMI/RFI) and eliminates ground loops. For more information
on fiber-optic cabling refer to the Distributed Power System Fiber-Optic Cabling
instruction manual (S-3009).
Local Power Interface module (LPI)
The LPI module is the interface between the SB3000 Power Module and the PMI rack.
It is through this module that information is sent to the SB3000 Power Module and
feedback data is sent back to the PMI rack.