Turbine Guide Vane Positioning Accuracy via Controller Deadband Signal
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Solution Overview
Problem
The existing systems for controlling turbine guide vane positions in gas turbines face challenges due to complex and non-linear relationships between transducer measurements and actual vane blade angles, resulting in precision issues and efficiency losses caused by manufacturing tolerances and wear in the linkage, leading to imprecise airflow control.
Innovation Solution
A method and system that utilize a controller to receive reference signals, measure actuator and angular positions, generate a deadband signal, and manipulate guide vanes based on this signal to improve positioning accuracy and repeatability by combining direct rotary angle measurements with traditional linear actuator position feedback, mitigating hysteresis effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional linear actuator position feedback is used, then the control system is simple, but the positioning precision deteriorates due to complex non-linear relationships and linkage wear
Solution Approach 1:
An intermediary computational layer is introduced in the controller that processes the linear actuator position signal through a stored non-linear transformation model. This model, representing the complex geometric and wear-related relationships, acts as a mediator that converts simple linear measurements into accurate angular position predictions, thereby achieving high positioning precision without requiring complex physical measurement devices at the vane itself.
Solution Approach 2:
The controller creates a computational copy or model of the physical linkage system's non-linear behavior, including geometric transformations and wear characteristics. This digital model is stored in memory and used to transform actuator position readings into accurate vane angle predictions, effectively replicating the complex physical relationships in the digital domain to achieve precision without physical complexity.
2Ease of operation
If transducer measurements are used to monitor actuator position, then the control system is easy to implement, but the airflow control precision deteriorates due to linkage manufacturing tolerances and wear
Solution Approach 1:
The system transforms the measurement parameter from direct angular measurement (which would require precision mechanical components) to linear actuator position measurement (which is easier to implement). A non-linear transformation model is then applied to convert this simplified parameter into accurate airflow control predictions, thereby maintaining ease of implementation while achieving high control precision through parameter transformation rather than direct precision measurement.
3Adaptability or versatility
If a hydraulic actuator with transducer feedback is employed, then the guide vanes can be adjusted, but positioning accuracy deteriorates due to the non-linear relationship between transducer measurement and actual vane angle
Solution Approach 1:
The system implements a computational feedback mechanism where the controller continuously monitors the linear actuator position, applies the non-linear transformation model to predict the actual vane angle, and uses this predicted angle for closed-loop control. This feedback approach maintains adaptability for vane adjustment while achieving measurement precision through software-based compensation rather than requiring precision mechanical feedback devices.
Data Source
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AI summary
Certain embodiments of the invention may include systems, methods, and apparatus for controlling turbine guide vane positions. According to an example embodiment of the invention, a method is provided for controlling at least one turbine guide vane. The method includes receiving a reference signal (602) associated with the at least one turbine guide vane, measuring an actuator position (622) and an angular position (624) associated with the at least one turbine guide vane, generating a deadband signal (621) based at least in part on the angular position (624), and manipulating the at least one turbine guide vane based at least in part on the deadband signal (621) and the reference signal (602).