SPECIFICATIONS
Part No.: IS200VAICH1CCC
Manufacturer: General Electric
Country of Manufacture: United States of America (USA)
Temperature: 0 to 60 oC
Size: 26.04 cm high x 1.99 cm wide x 18.73 cm deep
Power consumption: Less than 31 MW
Compressor stall detection: Detection and relay operation within 30 ms
Product Type: Analog Input Board
Availability: In Stock
Series: Mark VI
Functional Description
IS200VAICH1CCC is an analog input board developed by GE. It is a part of Mark VI control system. The Analog Input Board is designed to handle 20 analog inputs and efficiently control four analog outputs. It is is structured with a modular design, where each Analog Input terminal board is responsible for managing ten inputs and two outputs. This segmentation allows for scalability and ease of maintenance. Cables seamlessly connect these terminal boards to the VME rack, housing the processor board.
Features
- Analog Input Processing: The core functionality of the VAIC lies in its ability to convert analog inputs into digital values. This conversion process takes place within the VAIC processor board. Subsequently, the digital values are transmitted over the VME backplane to the VCMI (VME Communication Interface) board, facilitating communication with the overall control system.
- Input and Output Connections: To monitor a total of 20 inputs, the VAIC requires the utilization of two terminal boards.
- The robust connection between the terminal boards and the VME rack ensures seamless data transfer, enabling the VAIC to provide accurate and timely information to the controller.
- Output Signal Generation: For output control, the VAIC employs a reverse process, converting digital values into analog currents. These analog currents are then directed through the terminal board into the customer circuit, facilitating precise and controlled output signals.
Redundancy and Reliability
- The Board, with its robust design, efficient processing capabilities, and support for redundancy, plays a pivotal role in ensuring accurate and reliable analog input and output control within diverse industrial and electronic systems. Whether in simplex or TMR applications, the VAIC stands as a key component in facilitating seamless communication between analog signals and the broader control infrastructure.
- It is designed to ensure reliability in both simplex and triple modular redundant (TMR) applications. In a TMR configuration, input signals are distributed to three separate VME board racks (R, S, and T), each hosting a VAIC. Output signals are strategically managed through a proprietary circuit, utilizing all three boards. This redundancy enhances system robustness, as in the event of a hardware failure, the faulty is isolated, and the remaining two boards continue to generate the correct output current.
- TMR Fail-Safe Mechanism
- In the event of a hardware failure in a TMR setup, the faulty VAIC is promptly removed from the output circuit.
- The two remaining operational VAICs collaborate to sustain the desired output current, ensuring continuous system functionality and minimizing downtime.
- Simplex Configuration
- In a simplex configuration, the terminal board directs input signals to a single VAIC. This single VAIC is then responsible for generating all the required output currents.
- This configuration provides a streamlined setup for applications where redundancy is not a critical requirement.
Compressor Stall Detection
- In the realm of gas turbine control systems, ensuring the reliable detection of compressor stall is of paramount importance. The Analog Input Board plays a pivotal role in this process by incorporating compressor stall detection capabilities into its firmware. This sophisticated functionality is executed at an impressive rate of 200 Hz, providing real-time monitoring of critical parameters.
- Stall Detection Algorithms: The firmware offers a choice between two stall detection algorithms, tailored to different gas turbine types. Both algorithms leverage the first four analog inputs, which are scanned at the high frequency of 200 Hz. The selection between these algorithms is determined by the parameter CompStalType, allowing for flexibility and adaptability to specific turbine configurations.
- Small (LM) Gas Turbine Algorithm: For small LM gas turbines, the algorithm utilizes two pressure transducers. The configuration and operation of this algorithm are visually represented in the figure titled Small (LM) Gas Turbine Compressor Stall Detection Algorithm.
- Heavy-Duty Gas Turbine Algorithm: Conversely, the algorithm designed for heavy-duty gas turbines employs three pressure transducers. The corresponding figure, titled Heavy Duty Gas Turbine Compressor Stall Detection Algorithm, provides insights into the intricacies of this detection approach.
- Real-Time Inputs and Configured Parameters: To enhance clarity, the VAIC firmware distinguishes real-time inputs from configured parameters. The critical parameter, PS3 (compressor discharge pressure), becomes the focal point of stall detection. A drop in PS3, known as PS3 drop, serves as a primary indicator of a potential compressor stall. In addition to pressure drop, the algorithm calculates the rate of change of discharge pressure, dPS3dt, and compares these values with configured stall parameters, denoted as KPS3 constants. This comprehensive analysis ensures a robust and dynamic approach to stall detection.
- Compressor Stall Trip and Controller Interaction: Upon detecting a potential stall, the VAIC takes proactive measures to initiate a compressor stall trip. The resulting signal is seamlessly transmitted to the controller, where it serves as a trigger for a controlled shutdown. This shutdown signal is a crucial element in ensuring the safety and integrity of the gas turbine system.
- Shutdown Implementation: The shutdown signal, once received by the controller, can be strategically employed to activate fuel shut-off valves (FSOV) through the VCRC (Valve Control and Relay Cabinet) and the TRLY or DRLY (Trip Relay) board. This integration enables a swift and coordinated response to mitigate potential risks associated with compressor stall events.
- Incorporating compressor stall detection into the firmware enhances the overall safety and reliability of gas turbine systems. The ability to choose between algorithms, real-time monitoring of critical parameters, and seamless interaction with the controller underscores the sophistication and versatility of the Analog Input Board. As a crucial component in the gas turbine control architecture, the VAIC ensures that compressor stall events are promptly identified and addressed, contributing to the overall efficiency and longevity of gas turbine operations.
The WOC team is always available to help you with your Mark VI requirements. For more information, please contact WOC.
Frequently Asked Questions
What is IS200VAICH1CCC?
It is an analog input board developed by GE under the Mark VI series.
What is the purpose of hardware limit checking for analog inputs?
Hardware limit checking ensures that each analog input operates within preset high and low levels. If these limits are exceeded, a logic signal is triggered, and the input is no longer scanned. This enhances the reliability of the system.
How can I access details of individual diagnostics for analog inputs?
Detailed information on individual diagnostics is available through the toolbox associated with the VAIC. The toolbox provides a convenient interface for monitoring and troubleshooting specific issues.
Can diagnostic signals be latched individually, and how can they be reset?
Yes, diagnostic signals can be individually latched for persistent tracking. They can be reset using the RESET DIA signal, offering a controlled mechanism to clear and address diagnostic alarms.
What is the significance of system limit checking for each input on the VAIC?
System limit checking, based on configurable high and low levels, allows for generating alarms. These limits can be configured for enable/disable and latching/non-latching behavior. The RESET SYS signal is used to reset out-of-limit conditions.
