Compressor Capacity Switching With Intermediate Frequency Control
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Solution Overview
Problem
Household multi-split air conditioners face inefficiencies due to high energy consumption and unstable operation under varying loads, leading to reduced motor efficiencies and temperature fluctuations, especially when switching between single-cylinder and double-cylinder modes.
Innovation Solution
A method and device for controlling compressor capacity changes by determining an intermediate frequency to maintain stable operation, reducing sudden changes in output and ensuring system stability by adjusting capacity while maintaining the operating frequency at this intermediate frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the compressor capacity is changed directly from single-cylinder to double-cylinder mode, then the cooling or heating capacity is increased, but the system pressure becomes unstable and the output changes suddenly
Solution Approach 1:
The patent applies preliminary action by first adjusting the compressor frequency to an intermediate value before changing the cylinder mode. This preparatory frequency adjustment ensures that when the capacity switch occurs, the system pressure remains stable and the output transition is smooth, avoiding sudden changes that would occur with direct mode switching.
Solution Approach 2:
The patent uses an intermediate frequency as a mediator between the single-cylinder and double-cylinder operating modes. By transitioning through this intermediate frequency state, the system achieves a smooth capacity transition while maintaining pressure stability, effectively using the frequency as a buffer that mediates the abrupt change between capacity modes.
2Adaptability or versatility
If the compressor operates at low frequency under low load conditions, then the compressor can meet the cooling or heating demand, but the motor efficiency is reduced and energy consumption increases
Solution Approach 1:
The patent applies dynamics by making the compressor operate in different cylinder modes dynamically according to the load conditions. The system switches between single-cylinder and double-cylinder modes based on real-time demand, allowing the compressor to adapt its capacity to match the load while maintaining high motor efficiency in each operating state, thereby reducing overall energy consumption.
Solution Approach 2:
The patent uses parameter changes by adjusting both the frequency and cylinder mode parameters according to load conditions. By changing these operating parameters dynamically, the system optimizes motor efficiency across different load ranges, avoiding the energy waste that would occur from operating at low frequency under low load conditions.
3Adaptability or versatility
If the compressor switches between on and off states repeatedly, then the system can respond to varying load demands, but temperature fluctuations increase and comfortability decreases
Solution Approach 1:
The patent applies continuity of useful action by keeping the compressor running continuously in appropriate cylinder modes rather than switching on and off. By using the intermediate frequency transition and cylinder mode switching, the system maintains continuous cooling or heating output that adapts to load changes, eliminating temperature fluctuations and improving comfortability.
Data Source
AI summary
A method and a device for controlling a capacity change of a compressor, and a smart home appliance. The method includes: determining whether a capacity of the compressor is required to be changed; if yes, determining an intermediate frequency; changing the capacity of the compressor while maintaining the operating frequency of the compressor at the intermediate frequency; and the maintaining the operating frequency of the compressor at the intermediate frequency reduces a sudden change in output of the compressor after the changing the capacity.