Step Motor Phase Winding Short-Circuit Control for Rotor Vibration Attenuation
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Solution Overview
Problem
Step motors experience out-of-step issues due to rotor vibration during frequent starting and stopping, leading to instability and reduced performance, especially when the load exceeds rated design or when the rotor does not fully attenuate vibrations before starting.
Innovation Solution
Implementing a short-circuit control strategy for phase windings during the holding phase to rapidly attenuate rotor vibrations, combined with calculating the total equivalent static load torque for dynamic startup to ensure stable operation and prevent out-of-step conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the step motor is held in the working phase during the holding phase, then the motor can maintain position, but the rotor vibration cannot be rapidly attenuated and out-of-step may occur during subsequent startup
Solution Approach 1:
The patent dynamically switches the holding phase control mode from working phase (position holding) to short-circuit phase (vibration attenuation) based on real-time rotor state detection. When rotor vibration is detected during holding, the system transitions to short-circuit control to rapidly attenuate vibrations, then switches back to working phase control when vibrations are attenuated, optimizing both position stability and startup performance.
Solution Approach 2:
The system implements feedback control by detecting rotor vibration state during the holding phase and adjusting the control mode accordingly. The detection unit monitors rotor position and vibration characteristics, and the control unit uses this feedback information to determine when to switch between working phase control and short-circuit control, ensuring optimal performance.
2Productivity
If the step motor is switched to short-circuit phase immediately after deceleration, then rotor vibration can be rapidly attenuated, but the motor may lose position accuracy
Solution Approach 1:
The patent employs periodic switching between working phase control and short-circuit control during the holding phase. The system alternates between position holding (working phase) and vibration attenuation (short-circuit phase) in controlled intervals, ensuring that position accuracy is maintained while periodically reducing vibrations to prevent out-of-step conditions.
Solution Approach 2:
The control mode is dynamically adjusted based on rotor vibration detection. The system transitions from working phase control to short-circuit control only when vibration attenuation is needed, and switches back when position holding is prioritized, creating a dynamic balance between vibration reduction and position accuracy.
3Productivity
If the acceleration process is shortened to reduce operating time, then productivity increases, but the risk of out-of-step increases due to insufficient torque
Solution Approach 1:
The patent applies preliminary action by pre-attenuating rotor vibrations during the holding phase before startup occurs. By reducing vibrations in advance through short-circuit control, the rotor is better prepared for rapid acceleration, allowing shorter acceleration processes without increasing out-of-step risk.
Solution Approach 2:
The system applies preliminary anti-action by counteracting rotor vibrations before they can cause out-of-step conditions during acceleration. The short-circuit control during holding phase creates a counter-effect that dampens vibrations, preventing them from interfering with subsequent rapid acceleration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively reduces rotor oscillations, enhances stability, and allows for faster startup times, minimizing the risk of out-of-step occurrences and improving overall motor performance even when the rotor is not at equilibrium.
Implementation Method 1
a phase winding short-circuit control is adopted in the holding phase... A part of vibration energy in the holding phase is consumed in the rotor friction damping, and a part is consumed in the short-circuit loop
Implementation Method 2
The phase winding short-circuit causes the motor rotor to generate back-EMF when vibrating and generates current in the short-circuit loop, which generates a torque that prevents the motor from rotating
Implementation Method 3
A part of vibration energy in the holding phase is consumed in the rotor friction damping
Data Source
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AI summary
A method for controlling a step motor, wherein at least one phase winding has a short circuit state in the holding phase of a step motor. In the present invention, by adopting a short-circuit strategy for the phase windings in the step motor holding phase, the rapid attenuation of rotor oscillations is achieved. Compared with the control method of energizing the working phase and disconnecting the non-working phase, the present invention can quickly and effectively attenuate the rotor vibration and improve the operating stability of step motor. For motors that require frequent starting and stopping, only a short time interval is required to reduce the out-of-step caused by rotor vibration when the step motor starts.