Rockwell Automation SF3000 Parallel Gate Amplifier System - Manual (Page 9)

Introduction 1-1
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HAPTER
1
Introduction
The Parallel Gate Amplifier (PGA) system is used to amplify and distribute the gate
pulse signals produced by the AutoMax™ Distributed Power System's DC Power
Technology module. It can be used with multiple Reliance Power Modules or with
certain other vendor Power Modules. Please contact Reliance regarding the suitability
of other vendor Power Modules for use with the PGA system.
The system is comprised of three major components: the PGA Rack/Backplane, the
Power Supply module, and the PGA modules.
The Power Supply and PGA modules reside in a modular rack of either four slots or
eight slots. The four-slot rack holds the Power Supply and one or two PGA modules
(figure 1.1). The eight-slot rack holds the Power Supply and one to six PGA modules
(figure 1.2). Two channels (A and B) are provided for gate signals on the rack's
backplane. Channel A is used for forward gate signals and channel B for reverse gate
signals.
To connect to the two channels, two types of PGA modules are used. The Output-A
PGA module is used to access the signals from channel A. The Output-B PGA module
is used to access the signals from channel B. The two types of modules are not
interchangeable, but may be combined in the rack as needed to meet the
requirements of the application.
The amplified PGA output signals drive the gate coupling circuits in the DC Power
Modules. Each PGA module can simultaneously drive four six-thyristor power bridges
in one direction, either forward or reverse. With the maximum of six PGA modules
used in the system, a total of 24 power bridges (6 x 4) can be driven.
The PGA's standard DC bus voltage is +28 VDC, but the PGA module is capable of
handling DC bus voltages up to +100 VDC, if required by the application. Voltages
greater than the standard +28 VDC must be provided by an externally mounted power
supply, as described in chapter 3.
The available PGA configurations are listed in table 1.1. A two card PGA parallel
motoring and regenerating system example is shown in figure 1.3.