Dual-Compressor Refrigerator Control for Stable Pressure-Balanced Start-Up
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Reciprocating compressors, particularly linear compressors, face challenges in maintaining proper compression due to piston collisions and restricted movement when voltage is suddenly applied, leading to difficulties in load and voltage variation control, which affects the reliability and efficiency of refrigeration systems.
Innovation Solution
A compressor control apparatus that uses sensors and inverters to detect voltage and current, estimate stroke, and perform feedback control, allowing for independent control of two compressors in a refrigerator, with a predetermined start-up sequence to manage suction and discharge pressures, and includes a controller to generate control signals based on load and top dead center detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If voltage is suddenly applied to the compressor, then the compressor can start operation quickly, but the piston may collide with the cylinder wall or forward movement may be restricted
Solution Approach 1:
The control apparatus performs preliminary detection of voltage and current before full power application, estimates the stroke position in advance, and gradually increases power delivery. This preliminary action prevents sudden voltage application that would cause piston collision or movement restriction, while still enabling relatively quick compressor start-up.
Solution Approach 2:
The control apparatus continuously detects voltage and current, estimates stroke position based on this data, and uses feedback control to adjust power delivery. This feedback mechanism ensures the piston moves smoothly without collision while maintaining reliable operation during start-up and variable load conditions.
2Ease of manufacture
If the compressor is designed for simple structure, then manufacturing cost is reduced, but control capability under load and voltage variation is insufficient
Solution Approach 1:
The control apparatus replaces complex mechanical control mechanisms with electronic detection and control systems. By using voltage and current sensors combined with microcontroller-based feedback control, the system achieves superior adaptability to load and voltage variations while maintaining a relatively simple overall structure that is easier to manufacture.
Solution Approach 2:
The control apparatus dynamically adjusts electrical parameters (voltage and current) based on detected conditions and estimated stroke position. This parameter control approach provides excellent adaptability to varying loads and voltage conditions without requiring complex mechanical adjustments, simplifying the overall system structure.
3Productivity
If two compressors operate simultaneously, then refrigeration capacity is increased, but suction pressure and discharge pressure effects between compressors interfere with stable operation
Solution Approach 1:
The control apparatus for the second compressor performs preliminary detection and estimation before operation, and implements controlled start-up sequencing. This preliminary action allows both compressors to operate simultaneously for increased refrigeration capacity while managing pressure interference through coordinated control.
Solution Approach 2:
Each compressor control apparatus uses feedback control based on detected voltage, current, and estimated stroke position. This feedback mechanism allows simultaneous operation of two compressors by continuously adjusting each compressor's operation to compensate for suction and discharge pressure effects from the other, maintaining stable operation.
Data Source
AI summary
A compressor control apparatus and method, and a refrigerator including the same, are provided. In a refrigerator having two compressors, starting of two compressors may be staggered to reduce an effect of the suction pressure and discharge pressure between the two compressors, to provide for stable operation of the compressors, and improve reliability and power consumption.