Compressor and method for controlling the same

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Solution Overview

Problem

Compressors in refrigerators without a cycle matching function or controller face challenges in controlling the driving of linear motors, leading to inefficiencies and difficulties in varying cooling capacity.

Innovation Solution

A compressor system with a built-in controller that senses motor current and calculates phase differences to autonomously control the linear motor, adjusting cooling capacity based on detected load and phase differences, allowing for independent operation and efficient driving.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a compressor is installed in a refrigerator without a controller or cycle matching function, then the refrigerator can be made cheaper and more accessible, but the compressor cannot autonomously control its driving cycle and cooling capacity

Engineering Contradiction:
Improvecost reductionVSAvoidautonomous control capability
Core Design Contradiction:
Ease of manufactureVSExtent of automation

Solution Approach 1:

The compressor is equipped with a built-in controller that enables it to autonomously detect load conditions through current sensing and calculate appropriate phase differences, thereby self-regulating its driving cycle and cooling capacity without requiring an external refrigerator controller

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The compressor controller performs multiple functions including current sensing, phase difference calculation, driving cycle control, and cooling capacity regulation, making the compressor universally applicable to both refrigerators with and without controllers

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If the compressor autonomously controls its driving cycle, then cooling capacity can be optimized for different loads, but the device complexity increases due to added sensing and control components

Engineering Contradiction:
Improvecooling capacity optimizationVSAvoidcontrol system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The controller, current sensor, and phase difference calculation functions are integrated into a unified control system within the compressor, combining multiple functions into a single coordinated mechanism rather than separate independent systems

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If a built-in controller with current sensing is added to the compressor, then autonomous driving control and cooling capacity variation become possible, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvedriving cycle adaptabilityVSAvoidcontroller structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The compressor controller independently detects load conditions through current sensing and automatically adjusts driving parameters based on calculated phase differences, making the system self-regulating without external control intervention

Inventive Principle:
Principle #25Self-service

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

Enables efficient and stable operation of compressors in refrigerators without a controller, optimizing driving efficiency and maintaining cooling capacity within set limits, preventing unnecessary power input and enhancing system stability.

Implementation Method 1

a linear motor configured to provide a driving force to move the piston

Methodology Applied
Scientific EffectLinear motor: Linear Motor

Implementation Method 2

a sensor configured to sense a motor current of the linear motor

Methodology Applied
Scientific EffectElectrical sensing: Ohmmeter

Data Source

PatentEP3173623B1Compressor and method for controlling the same
Publication Date: 2020.08.12 LG ELECTRONICS INC
  • EP3173623B1 patent drawingFigure 1A~1B
  • EP3173623B1 patent drawingFigure 2
  • EP3173623B1 patent drawingFigure 3A

AI summary

A compressor (100) installed at an apparatus including a refrigeration cycle, includes: a piston which reciprocates in a cylinder; a linear motor (110) configured to provide a driving force to move the piston; a sensor (141) configured to sense a motor current of the linear motor; and a compressor controller (180) configured to detect information related to a load of the apparatus, in a separated manner from a controller which controls a body of the apparatus, wherein the compressor controller calculates a phase difference between a stroke of the piston and the sensed motor current, and wherein the compressor controller compares the calculated phase difference with a reference phase difference, and controls a driving of the linear motor in correspondence to the detected load, according to a result of the comparison.