Method of adjusting electronic expansion valve of air conditioner
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Solution Overview
Problem
The existing PID control methods for electronic expansion valves in air conditioners are inflexible and unable to accurately respond to varying air conditioner capacities and working conditions, leading to suboptimal energy efficiency ratios.
Innovation Solution
A method that adjusts the integral coefficient of the PID algorithm based on real-time outdoor environment temperatures and compressor running frequencies, using different rules to select appropriate integral coefficients for varying conditions, thereby improving the accuracy and reliability of electronic expansion valve control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed PID algorithm is used for electronic expansion valve control, then the control structure is simple, but the control accuracy deteriorates under varying air conditioner capacities and working conditions
Solution Approach 1:
The patent implements dynamic adjustment of the integral coefficient in the PID algorithm based on real-time outdoor temperature and compressor running frequency. The controller dynamically selects different integral coefficient values from predefined sets according to the current operating conditions, making the control system adaptive to varying air conditioner capacities and working conditions while maintaining reasonable structural complexity.
2Speed
If the integral coefficient is increased to improve response speed, then the response speed improves, but the system stability deteriorates due to increased fluctuations and oscillations
Solution Approach 1:
The patent dynamically adjusts the integral coefficient based on operating conditions. When outdoor temperature is high (≥first threshold) or low (≤second threshold) combined with specific compressor frequency ranges, a smaller integral coefficient is selected to reduce fluctuations and maintain stability. When conditions are moderate, a larger integral coefficient is used to improve response speed, thus dynamically balancing response speed and stability.
Solution Approach 2:
The patent changes the integral coefficient parameter of the PID algorithm according to different operating conditions (outdoor temperature and compressor frequency). By selecting from multiple predefined integral coefficient values, the system optimizes the balance between response speed and stability for each specific operating scenario.
3Stability of the object's composition
If the integral coefficient is decreased to improve system stability, then the stability improves, but the response speed deteriorates
Solution Approach 1:
The patent implements conditional dynamic adjustment of the integral coefficient. Instead of using a fixed small value for stability, the system selects from multiple integral coefficient values based on real-time operating conditions, achieving both stability when needed and fast response when appropriate.
Solution Approach 2:
The patent changes the integral coefficient parameter dynamically based on outdoor temperature and compressor frequency. The controller selects from a set of predefined integral coefficient values, allowing the system to achieve fast response when conditions permit while maintaining stability when operating conditions require it.
4Device complexity
If a fixed integral coefficient is used, then the control algorithm is simple, but the adaptability to different working conditions deteriorates
Solution Approach 1:
The patent makes the control algorithm dynamic by implementing conditional judgment based on outdoor temperature and compressor running frequency. The controller dynamically selects from multiple integral coefficient values according to the current operating conditions, significantly improving adaptability while adding only moderate complexity through predefined selection rules.
Solution Approach 2:
The patent changes the integral coefficient parameter according to different working conditions (outdoor temperature ranges and compressor frequency ranges). By selecting from multiple predefined coefficient values based on conditional judgments, the system achieves high adaptability to various air conditioner capacities and operating scenarios.
Data Source
AI summary
Provided is a control method on electronic expansion valve in air conditioner, which comprises: obtaining a real-time running frequency of compressor, a real-time exhaust temperature and a real-time outdoor environment temperature as the compressor running; if the air conditioner working in cooling mode, using a first set rule or a second set rule to obtain an integral coefficient in which the selection is based on the comparison of the real-time outdoor environment temperature and a first set outdoor environment temperature; if the air conditioner working in heating mode, using a first set rule or a third set rule to obtain an integral coefficient in which the selection is based on the comparison of the real-time outdoor environment temperature and a second set outdoor environment temperature; performing a PID control on the electronic expansion valve by using an error of the difference between real-time exhaust temperature and a set target exhaust temperature. The method realizes an accurate and stable control on opening amount of electronic expansion valve in air conditioner.