Double PI Corrector for Asymmetrical Valve Response Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The three-way valve in turbomachines exhibits functional asymmetry, leading to differing response times and non-linear behavior based on operating directions, which conventional control strategies struggle to manage effectively, resulting in temperature regulation inaccuracies and instability.
Innovation Solution
A control method employing two distinct proportional-integral correctors, one fast and one slow, based on the operating direction, with a hysteresis parameter to avoid oscillations and an incrementer to manage transient effects, allowing for adaptive control to compensate for asymmetry and maintain stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a single conventional controller is used for the valve, then the control structure remains simple, but the response time and stability are compromised due to the valve's asymmetrical behavior in different operating directions
Solution Approach 1:
The control method segments the single controller into two distinct proportional-integral correctors, each optimized for a specific operating direction of the valve. The first corrector handles the fast-response direction with aggressive parameters, while the second corrector manages the slow-response direction with conservative parameters, eliminating the performance compromises of a unified controller
Solution Approach 2:
The control system dynamically switches between the two correctors based on the current operating direction of the valve. This dynamic adaptation allows the system to optimize control parameters in real-time according to the valve's asymmetrical behavior, improving both response time and stability across different operating conditions
2Speed
If a fast controller is designed to meet speed requirements, then response time improves, but overshoot increases during fast-response operating directions
Solution Approach 1:
The control system applies different local control qualities through two distinct correctors: the first corrector uses aggressive proportional-integral parameters optimized for fast response in one direction, while the second corrector uses conservative parameters optimized for stability in the opposite direction. Each corrector is locally optimized for its specific operating direction, preventing overshoot while maintaining speed
3Stability of the object's composition
If a slow controller is designed to reduce overshoot, then stability improves, but response time deteriorates during slow-response operating directions
Solution Approach 1:
The control system applies different local control qualities through two distinct correctors: the first corrector uses aggressive proportional-integral parameters optimized for fast response in one direction, while the second corrector uses conservative parameters optimized for stability in the opposite direction. Each corrector is locally optimized for its specific operating direction, preventing overshoot while maintaining speed
4Ease of manufacture
If conventional linear control strategies are used, then the control implementation remains straightforward, but the non-linear asymmetrical behavior of the valve cannot be effectively managed
Solution Approach 1:
The control system dynamically adapts its parameters based on the operating direction of the valve. By switching between two proportional-integral correctors with differently tuned parameters, the system accounts for the non-linear asymmetrical behavior of the valve, achieving accurate temperature regulation while maintaining relatively simple control implementation
Data Source
Figure 1
Figure 2
AI summary
The invention concerns a method for controlling a mechanism (10) displaying asymmetrical behaviour, the mechanism (10) comprising a first operating direction (F+) and a second operating direction (F-), the control method making it possible to generate, using a control module (24) of a computer (20), a control signal (x_com) from a setpoint signal (x_cons), in which - when the setpoint signal (x_cons) indicates that the mechanism (10) should be operated in the first direction (F+), the control module (24) applies a first corrector (100) to the setpoint signal (x_cons) in order to generate a control signal (x_com), - when the setpoint signal (x_cons) indicates that the mechanism (10) should be operated in the second direction (F-), the control module (24) applies a second corrector (100) to the setpoint signal (x_cons) in order to generate a control signal (x_com), and in which the first and second correctors (100, 200) have different parameters (Kp1, Kp2, Ti1, Ti2), in order to compensate for the asymmetrical behaviour of the mechanism (10).