Linear Compressor Driving Control via Phase Difference Inflection Point
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing driving controlling methods for linear compressors experience stroke trembling and reduced reliability when the stroke exceeds the top dead center (TDC), and varying the input current leads to unstable power application and cooling capacity variations.
Innovation Solution
A driving controlling apparatus and method that detect the TDC by a phase difference inflection point, increase the current applied to the linear motor when the stroke is more than the TDC, and utilize a PWM controlling unit and inverter to adjust the current, ensuring stable control and preventing overstroke.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the input current is decreased when the stroke is more than the TDC, then the power consumption is reduced, but the stroke trembling occurs and the reliability is lowered
Solution Approach 1:
The patent implements a feedback control mechanism where the controller continuously monitors the stroke position and adjusts the input current accordingly. When the stroke exceeds the TDC, the controller increases the current to generate greater electromagnetic force that pushes the piston back toward the TDC, preventing stroke trembling and ensuring stable operation.
Solution Approach 2:
The patent dynamically changes the electrical parameters (input current magnitude) based on the mechanical state (stroke position). By detecting when the stroke is more than the TDC and responding with increased current, the system adapts its operating parameters to maintain reliable stroke control while managing power consumption efficiently.
2Productivity
If the input current is increased to increase the stroke, then the cooling capacity is improved, but the power applied varies greatly thus reducing reliability
Solution Approach 1:
The feedback control system monitors stroke position and provides continuous adjustment of the input current. This ensures that the motor receives only the necessary current to achieve the desired stroke and cooling capacity, preventing excessive power variations and maintaining stable operation even at high cooling capacities.
Solution Approach 2:
The patent employs dynamic current control that adjusts the input current in real-time based on the required stroke and load conditions. This dynamic adjustment allows the system to optimize cooling capacity while maintaining power stability, as the current is precisely controlled to match the actual operational requirements rather than being constantly high.
3Adaptability or versatility
If the voltage is varied to control the stroke, then the compression ratio is adjusted, but the TDC control becomes unstable when the stroke is more than the TDC
Solution Approach 1:
The patent replaces the traditional voltage-based LC resonance control method with a direct current control approach. By controlling the input current to the linear motor rather than varying voltage for resonance, the system achieves more stable and predictable TDC control, especially when the stroke exceeds the TDC position.
Solution Approach 2:
The patent changes the control parameter from voltage (which affects LC resonance) to current (which directly affects electromagnetic force). This parameter change provides more direct and stable control over the piston motion and TDC position, improving the stability of TDC control while maintaining the ability to adjust compression ratio.
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 solution stabilizes the top dead center control, reduces stroke trembling, and enhances the reliability of the linear compressor by effectively managing the current applied to the motor, thereby maintaining consistent power and cooling capacity.
Implementation Method 1
a linear compressor reciprocates a piston with using a linear motion of a motor by directly connecting the piston to a mover of a linear motor
Data Source
AI summary
A driving controlling apparatus for a linear compressor, comprises a controlling unit for detecting a TDC by a phase difference inflection point between a stoke and a current with increasing the stroke by controlling the current applied to a linear motor, and for varying the current applied to the linear motor based on the detected TDC.