Electronic Expansion Valve Motor Positioning for Slip-Free Start
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Solution Overview
Problem
The existing drive control techniques for electronic expansion valves in inverter air conditioners face challenges with insufficient starting torque and positional deviations between the rotor and stator, leading to ineffective driving and incorrect valve body opening control, especially when the valve has not been used for a long time or is obstructed by oil or foreign matter.
Innovation Solution
A drive control device and method that performs secondary positioning of the motor before and after starting, using holding currents and additional pulse signals to enhance torque and maintain correct rotor and stator alignment, ensuring accurate valve body opening control by determining and applying specific pulse and current durations to manage magnetic field interactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the electronic expansion valve is directly turned on and off at normal operating rate without secondary positioning, then the control is simple and fast, but the starting torque is insufficient causing slip and step-out when the valve has not been used for a long time or is obstructed
Solution Approach 1:
The patent applies preliminary action by performing secondary positioning before the main driving operation. The control device executes additional positioning pulses before normal operation to ensure the motor is properly aligned and ready, preventing slip and step-out conditions while maintaining fast response during actual valve adjustment
2Reliability
If holding current is applied for extended duration after stopping the motor, then the magnetic field holding torque is increased to prevent rotor displacement, but the energy consumption increases and the rotor position may still deviate under refrigerant pressure impact
Solution Approach 1:
The patent applies preliminary action by performing secondary positioning before the main driving operation. The control device executes additional positioning pulses before normal operation to ensure the motor is properly aligned and ready, preventing slip and step-out conditions while maintaining fast response during actual valve adjustment
Solution Approach 2:
The patent implements feedback by monitoring the actual rotor position and comparing it with the target position. The control device adjusts the holding current duration and intensity based on detected position deviations, ensuring accurate positioning while minimizing energy consumption by applying current only when necessary
3Reliability
If secondary positioning is performed before and after motor operation with holding currents and additional pulse signals, then the starting torque is enhanced and positional accuracy is improved, but the control complexity increases
Solution Approach 1:
The patent applies self-service by implementing an automatic detection and correction mechanism. The control device autonomously determines whether secondary positioning is needed based on operational conditions, and automatically executes the positioning sequence without requiring external intervention or complex manual control logic
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
This approach effectively addresses the issues of insufficient starting torque and positional deviations, ensuring the electronic expansion valve can be correctly driven and maintained at the proper opening, enhancing the reliability and performance of air conditioning systems.
Implementation Method 1
a current is applied to the stop pulse signal of the electronic expansion valve, thereby making the magnetic field between the stator and the rotor of the motor of the electronic expansion valve form a holding torque
Data Source
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AI summary
A drive control device and method for an electric expansion valve is disclosed. In the disclosure, before applying a drive pulse signal corresponding to a rotary pulse number to a motor of the electronic expansion valve, a secondary positioning is performed on a relative position between stator magnetic field of the motor and rotor magnetic field of the motor by applying a holding current of a first duration time to the motor, applying a pulse signal of an additional pulse number to the motor, and applying a holding current of a second duration time to the motor, and a similar secondary positioning operation is also performed on the motor after applying the drive pulse signal corresponding to the rotary pulse number to the motor of the electronic expansion valve, which ensures that the electronic expansion valve operates according to the drive pulse signal corresponding to the rotary pulse number.