GE EX2100e Excitation Control 35A and 120A Regulator Systems Digital Controller

Digital Controller (IGBT-based Systems)

The EX2100e Excitation control products offer a Regulator control system in a 800 mm

(32 in) enclosure with supporting hardware based on the particular application. Other

packaging options are available. The Regulator system can be purchased as part of a

finished cabinet, or individual components can be shipped separately for onsite mounting

to better serve retrofit applications.

Power conversion consists of an input section, a dc link, and the converter output section.

The input section is a 3-phase diode bridge with input filters. The system accepts a

primary ac input range of 90 to 280 Vrms, nominal for the 35 A system, and up to 480 V

rms for the 120 A system. The ac input is 480 Hz (maximum), which can be supplied as

1-phase or 3-phase from a permanent magnet generator (PMG), auxiliary bus, or

generator terminals.

As a backup, the system accepts a secondary power input from a dc battery bank (125 to

250 Vdc nominal). The dc secondary input is diode-isolated and combined with the

3-phase diode bridge output. These sources energize the dc link, which is an unregulated

source voltage for the control output power through the IGBTs. The dynamic discharge

(DD) circuit limits the dc link voltage level during events such as load rejection or unit trip.

The converter output section uses IGBTs to pulse-width modulate the dc link source

voltage to its final value. The chopping frequency of the IGBTs is approximately 1.000

Hz. This output is fed to the exciter field as a regulated voltage or current. An output

shunt monitors the field current. Continuous dc output is provided up to 100% rating with

temporary forcing capabilities up to 210%. Regulated output flows through a dc contactor

to the exciter field.

The EX2100e Regulator system contains interface boards that are interconnected through

a high-speed serial link (HSSL) and cabled to their associated I/O terminal boards.

DualControl (Power Bridge Warm Backup)

The EX2100e Regulator system is available in a warm backup (WBU) configuration,

which includes dual exciter control I/O and protection. The control includes M1 (Master

One) and M2 (Master Two), with two IGBT bridges that can accept separate or shared ac

input power. The control configuration can also share a common dc output circuit to the

exciter field through the transfer module. M1 and M2 are independent controls, each with

automatic and manual regulator functions. Either M1 or M2 can control bridge firing, as

determined by the operator. In the WBU configuration, M1 controls bridge #1. and M2

controls bridge #2.

To process application software, two independent Universal Controller Stand-alone Board

Version B (UCSB) controllers, with separate PCMs and an output selector module (SCM

or TCM), provide the dc output current for the exciter field (or SCTcontrol winding).

The active power bridge receives the gating commands from the active control (M1 or

M2), and supports the full-field voltage and current needs of the exciter field while the

backup power bridge’s gating circuit is inhibited. The operator has full control to select

which of the dual power bridges is active or inactive. Bi-directional, bumpless transfer

between active and inactive bridges is standard. The active master can also self-diagnose

a failure or missed operation and activate the backup control and power bridge without

operator intervention.