IS200EXMDG1B GE EX2100, Exciter MD Feedback Board

Description:

Functional Description
The IS200EXMDG1B, an exciter MD feedback board engineered by General Electric, is integral to the EX2100 excitation system. This system generates field excitation current to manage both the AC terminal voltage and reactive volt-amperes of generators, serving as a comprehensive static excitation solution for new and retrofitted steam, gas, and hydro turbines.

Features
This board incorporates two male pin connectors and two female connectors, complemented by two metal oxide varistors (MOVs). It features a variety of pin connectors of different sizes, including a ninety-degree angled connector along one edge. The board's perimeter displays several codes and its alphanumeric catalog number, which is crucial for accurate part reordering.
The board includes two Augat connectors—one being a 2x3 configuration and the other a 3x3 setup—along with two make pins and two female connection points. Additionally, it boasts two vertical pin connectors of varying sizes and two female connection points.

Characteristics
As a functional module in generators, the Exciter MD Feedback Board plays a pivotal role in feeding back information to the exciter control system. Its primary function is to convert the DC output signal from the exciter's rotating diodes into a proportional AC signal, which is then relayed to the exciter control system to modulate the exciter field current.
Maintaining precise regulation of the exciter field current is essential for upholding the generator's output voltage stability and reliability. The feedback mechanism provided by this board ensures optimal exciter field current levels, thereby guaranteeing dependable generator performance.
Key attributes enhancing its functionality include a microprocessor-based architecture for heightened accuracy and rapid response times, alongside built-in diagnostic tools that facilitate fault detection and isolation.
The board handles numerous input and output signals: a DC input from the exciter's rotating diodes, an AC output proportional to the input signal, and various control signals to govern the exciter field current.

Exciter Software
The exciter software, residing within controllers, is configured and deployed via a toolbox interface. Here, the software is depicted through interconnected control blocks illustrating signal flow. Measurements of the generator field, stator currents, and voltages are integrated into the control system.
In standard operation, the AC regulator is activated. PT and CT generator voltages and currents are routed to the EPCT board, functioning as a signal conditioner to isolate and scale the signals before feeding them into the controller. These conditioned signals undergo conversion algorithms within the software to compute system variables utilized by the regulator, limiter, and protection functions.

Product Attributes
These boards connect to three Exciter Main Input/Output boards (EMIO) for redundancy control and one EMIO board for simplex control via the Exciter backplane. Control relays for flash relays 53A and 53B, as well as magnetization relay KDEP, are present on the circuit board.
The EXHS regulates the exciter deactivation board and transmits a deactivation status signal to EMIO. The Crowbar status signal is conditioned by EXHS prior to its transmission to EMIO via the EXRE Magnetization Control Board.
Three contact inputs from 41, 53A, and 538 on the EXHS are powered by 70 V DC, with their feedback closely monitored. An exciter source energizes these contacts, generating a status signal sent to EMIO.

Datasheet Link:

IS200EXMDG1B GE EX2100, Exciter MD Feedback Board PDF Datasheet