Electric Valve Torque Feedback Control for Accurate Sealing
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Solution Overview
Problem
Existing electric valve/door systems using AC asynchronous motors suffer from low torque control precision, limited dynamic torque and speed ranges, and poor precision in torque, speed, and position control due to mechanical clearances and parameter drifts, leading to improper sealing and motor burnout.
Innovation Solution
A control apparatus for electric valves/doors that includes an AC asynchronous motor, a transmission device, and a valve driver. The valve driver collects real-time torque data and uses a PID control algorithm to adjust the output torque in real-time, ensuring precise control and overcoming limitations of the AC asynchronous motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If point triggering method is used to stop valve opening/closing, then the valve can be stopped at predetermined positions, but mechanical clearance and precision error cause improper sealing or motor burnout
Solution Approach 1:
The patent employs feedback control by continuously monitoring the actual position of the valve through position sensors and comparing it with the target position. The control system adjusts the motor output in real-time based on the position deviation, ensuring accurate stopping at predetermined positions without relying on mechanical travel switches. This eliminates the mechanical clearance issues and improves sealing reliability.
Solution Approach 2:
The patent replaces the mechanical point triggering system (travel switches with contact points) with an electronic control system that uses position sensors and electronic signals to detect and control valve position. This substitution eliminates mechanical wear, clearance, and precision errors inherent in mechanical switching systems.
2Device complexity
If AC asynchronous motor is used for driving valve/door, then structure is simple and cost is low, but torque control precision is low and dynamic range is limited
Solution Approach 1:
The patent implements dynamic torque control by continuously adjusting the motor output torque based on real-time feedback from torque sensors and position sensors. The control system modifies motor parameters during operation to optimize torque output for different stages of valve opening/closing, enabling precise torque control and expanded dynamic range while maintaining the simplicity of AC asynchronous motor structure.
Solution Approach 2:
The patent changes motor operating parameters (such as frequency, voltage, and current) in real-time during valve operation to optimize torque output. By dynamically adjusting these parameters based on feedback signals, the system achieves precise torque control and extended dynamic range without changing the fundamental motor structure.
3Device complexity
If fixed rotational speed is used for valve running, then motor operation is simple, but speed of opening/closing remains unchanged and dynamic load is overloaded
Solution Approach 1:
The patent implements dynamic speed control by continuously adjusting the motor rotational speed based on real-time feedback from position sensors and control algorithms. The system divides the valve operation into multiple stages and optimizes speed for each stage, enabling faster overall operation while preventing overload through reduced speed during high-torque phases.
Solution Approach 2:
The patent employs periodic action by dividing the valve opening/closing process into distinct stages (acceleration, constant speed, deceleration) with optimized speed profiles for each stage. This staged approach improves overall productivity while managing dynamic loads effectively.
Data Source
AI summary
An electric valve/door, and a control apparatus and method thereof are provided. The electric valve/door includes a control apparatus. The control apparatus includes an alternating current (AC) asynchronous motor, a transmission device, and a valve driver. The valve driver is connected to the AC asynchronous motor. The AC asynchronous motor is connected to the valve/door through the transmission device. The valve driver is configured to collect information of a real-time torque of the AC asynchronous motor or the valve/door during operation, and take a set torque of the valve driver as an input and the real-time torque as a feedback to immediately correct an output torque of the valve driver or a limit value of the output torque by using a proportional-integral-derivative (PID) control algorithm, to meet requirements for response speed and control precision of each stage in opening and closing processes of the valve/door.