Rockwell Automation SA3100 AutoMax Distributed Power System - Manual (Page 32)

2-12 AutoMax Distributed Power System Overview
The AC Power Technology module performs the calculations required to generate the
pulse-width modulated (PWM) signals that fire the power devices in the AC Power
Module based on the required feedback inputs and the inner loop reference values
received from the UDC module and the PMI Processor.
The Power Module Interface port on the faceplate of the AC Power Technology module
provides direct connection to the AC Power Module and is used to receive all drive
feedback signals and transmit gate driver signals. One LED on the faceplate indicates
all conditions have been met to allow the output of firing signals to the power devices.
2.4.2.2 Medium Power SA3000 AC Power Modules
The Medium Power SA3000 AC Power Modules incorporate state-of-the-art IGBT
(insulated gate bipolar transistor) technology for variable speed control of induction
motors. The modules can operate from either 3-phase AC input or DC bus power.
Rectified, filtered DC voltage is fed from the rectifier (internal diode rectifier or external
DC bus) circuitry to the inverter bridge, which consists of three replaceable Intelligent
Power Modules and their snubber circuitry. Pulse-width modulation (PWM), a control
technique which results in a relatively smooth, synthesized AC sine wave, is used to
produce variable voltage/variable frequency output to the motor.
The Power Modules contain built-in diagnostics to provide warning and fault detection.
Diagnostics are run continuously by the PMI to detect problems like over temperature,
DC bus overvoltage/undervoltage, excess ground currents, IGBT overcurrent, and
communication faults.
2.4.3 SA3000 High Power Drives (534-1457 Amp)
The hardware components of the High Power SA3000 drive are an eight-slot PMI
rack, the Local Power Interface module, and the High Power AC Power Module all
contained in a floor-mounted cabinet. The High Power AC Power Modules consist of
one to three power units connected in parallel to obtain higher current output, as
required. These components are shown in figure 1.4 and are described in the sections
that follow.
2.4.3.1 SA3000 Eight-Slot PMI Rack and Modules
An eight-slot version of the PMI rack houses the additional modules necessary for
firing and paralleling the power units.
The first three slots contain the same Power Supply module, PMI Processor module,
and Resolver & Drive I/O module as described in section 2.3.1. The remaining slots
contain an AC Power Technology module, a Parallel Interface module, and up to three
Gate Driver Interface modules (one for each power unit). Refer to figure 2.6.