Air Conditioner Compressor Frequency Control for Resonance Avoidance

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Solution Overview

Problem

Existing air conditioners face resonance issues between the compressor and outdoor unit due to manufacturing errors and varying installation conditions, leading to noise and potential damage, as the pre-measured resonance frequencies differ from actual operating frequencies.

Innovation Solution

A control method that adjusts the compressor's operating parameters based on the difference in vibration displacements, using a displacement sensor to detect and calculate adjustments to prevent resonance, including adjusting the compressor frequency by adding products of displacement differences and coefficients, and controlling the adjustment direction and amount based on frequency trends.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the compressor operates at variable frequencies to improve cooling efficiency, then the cooling performance is improved, but resonance occurs between the compressor and outdoor unit causing noise and potential damage

Engineering Contradiction:
Improvecooling efficiencyVSAvoidresonance noise
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system uses vibration sensors to detect real-time vibration signals from the outdoor unit, processes these signals through FFT analysis to identify resonance frequencies, and feeds this information back to the controller which adjusts the compressor frequency away from resonance points. This closed-loop feedback mechanism allows the system to maintain high cooling efficiency while dynamically avoiding resonance conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the operating frequency parameter of the compressor based on detected vibration characteristics. When resonance is detected through vibration analysis, the controller adjusts the frequency parameter to shift away from problematic resonance points, thereby eliminating noise and vibration while maintaining efficient operation.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If pre-measured resonance frequencies are used to avoid resonance, then resonance avoidance is simplified, but manufacturing errors and installation variations cause the pre-measured frequencies to differ from actual resonance frequencies

Engineering Contradiction:
Improveresonance avoidance controlVSAvoidresonance frequency accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system performs self-diagnosis by using built-in vibration sensors to automatically detect and identify its own resonance frequencies during operation. Through FFT analysis of vibration signals, the system determines actual resonance points without requiring external measurement equipment or manual calibration, thereby adapting to manufacturing variations and installation conditions.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Instead of using fixed pre-measured resonance frequencies, the system dynamically determines resonance frequencies based on real-time vibration characteristics. The resonance frequency identification adapts to changing operating conditions, manufacturing tolerances, and installation variations, ensuring accurate resonance avoidance across different scenarios.

Inventive Principle:
Principle #15Dynamics

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

Effectively prevents resonance between the compressor and outdoor unit, reducing noise and potential damage by dynamically adjusting compressor frequencies according to real-time vibration conditions.

Implementation Method 1

obtaining a vibration displacement of the exhaust pipeline during the operation of the air conditioner

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

there must be some operating frequencies that will cause a resonance between the compressor and the outdoor unit

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3748250B1Control method for air conditioner
Publication Date: 2024.12.18 QINGDAO HAIER AIR CONDITIONING ELECTRONICS CO LTD
  • EP3748250B1 patent drawingFigure 1
  • EP3748250B1 patent drawingFigure 2
  • EP3748250B1 patent drawing

AI summary

The present disclosure belongs to the technical field of air conditioners, and particularly relates to a control method for an air conditioner. The present disclosure aims to solve the problem that a resonance phenomenon easily occurs between an outdoor unit and a compressor of existing air conditioners. To this end, the air conditioner of the present disclosure includes a compressor and a pipeline connected to the compressor, and the control method of the present disclosure includes the following steps: obtaining a vibration displacement of the pipeline during the operation of the air conditioner and recording it as a first vibration displacement; obtaining the vibration displacement of the pipeline again after a preset time has elapsed and recording it as a second vibration displacement; and selectively adjusting operating parameters of the compressor according to the first vibration displacement and the second vibration displacement. In the present disclosure, the vibration condition of the outdoor unit is determined through the real-time vibration condition and the vibration change condition of the pipeline so that the air conditioner can selectively change the operating parameters of the compressor according to the vibration condition of the outdoor unit; that is, the vibration condition of the compressor is selectively changed to effectively avoid the problem of pipeline damage caused the resonance phenomenon between the compressor and the outdoor unit.