GE IS200TVBAH2AAA Terminal Voltage Board

Product Overview

The GE IS200TVBAH2AAA is a critical component within the Mark VIe series of Speedtronic gas/steam turbine management and control systems manufactured by GE Industrial Automation (formerly GE Energy, part of GE Vernova). This specific board is formally known as a Terminal Voltage Board (TVB).

Primary Function

Its core function is to supply isolated and regulated excitation power to the voltage transformers (VTs) connected to the generator output terminals within a turbine control system. This excitation power is essential for the accurate measurement and monitoring of generator terminal voltage.

Key Features and Specifications

1. Voltage Transformation & Isolation:
   • Accepts a nominal +28V DC control power input (typically sourced from the Mark VIe control cabinet’s DC power supply system).
   • Provides a precisely regulated, isolated AC excitation voltage output to the Voltage Transformers (VTs). Common VT excitation voltages supplied include ±90V DC.
   • The isolation is crucial for safety, noise immunity, and ensuring accurate voltage measurement reference points.
2. Integration with Mark VIe System:
   • Designed specifically for installation within Mark VIe turbine control cabinets.
   • Plugs directly into the Mark VIe backplane (terminal board like an IS200TBCIH2C) via its connector, drawing input power and distributing its output signals through the backplane wiring.
   • Interfaces seamlessly with the Mark VIe controller (e.g., IS200ERPGH1A) and I/O packs handling generator metering and protection.
3. Hardware Version:
   • The “AH2” suffix indicates this is the second hardware revision (Rev H2) of the Terminal Voltage Board design. Earlier revisions (e.g., AH1) exist.
   • The “AAA” suffix typically denotes a specific factory configuration or ordering variant, though it usually represents the standard base configuration for this board type.
4. Critical Role in Protection & Control:
   • Accurate generator terminal voltage measurement is fundamental for: 
     • Automatic Voltage Regulation (AVR): Maintaining stable generator output voltage.
     • Protection Relaying: Functions like overvoltage (59), undervoltage (27), and loss-of-field (40) protection rely on precise VT signals.
     • Synchronization (25): Matching generator voltage to the grid voltage during connection.
     • Power Monitoring & Control: Calculating real power (MW), reactive power (MVAR), and power factor.
   • The IS200TVBAH2AAA ensures the VTs receive clean, stable excitation power for reliable measurement.
5. Physical Characteristics:
   • Standard Eurocard format PCB (approximating 6U x 160mm depth).
   • Components include transformers, capacitors, resistors, diodes, and integrated circuits necessary for regulation and isolation.
   • Features a robust edge connector for backplane insertion.
   • May have status LEDs (though less common than on controller cards).
6. Redundancy (Common Practice):
   • In critical generator applications, it is common practice to have redundant VT circuits and associated excitation supplies.
   • A Mark VIe cabinet might contain multiple IS200TVBAH2AAA boards (or equivalents) to excite redundant sets of VTs feeding redundant generator protection channels.

Typical Application

The IS200TVBAH2AAA is deployed in power generation facilities utilizing GE Mark VIe controllers, including:

• Gas Turbine Power Plants
• Steam Turbine Power Plants
• Combined Cycle Power Plants (CCPP)
• Other industrial facilities with large synchronous generators managed by Mark VIe.

Importance

By providing reliable and isolated excitation power to the generator Voltage Transformers, the IS200TVBAH2AAA plays a vital role in ensuring the accuracy, safety, and stability of generator voltage measurement. This accuracy is fundamental to the overall performance, protection, and grid compliance of the entire turbine-generator unit.