Compressor driving device, compressor pressure protection method, and air conditioner

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Solution Overview

Problem

The challenge is to ensure safe and reliable operation of a compressor in air conditioning systems by preventing overpressure, which can cause damage if the compressor fails to stop operating timely during abnormal pressure conditions.

Innovation Solution

A compressor driving device with a pressure switch and driving control circuit that disconnects power to the compressor when pressure exceeds a preset threshold, using a relay module and rectifier circuit to convert AC to DC for safe shutdown, and includes a detection mechanism to verify the pressure switch state and prevent misoperation due to relay failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If relay contacts are used for high current switching, then the circuit can be simplified, but the relay contacts may degrade and fuse under abnormal conditions, causing the compressor to fail to stop

Engineering Contradiction:
Improvecircuit complexityVSAvoidrelay contact reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the detection circuit continuously monitors whether the compressor power supply has been effectively cut off when the pressure switch opens. The detection circuit measures the voltage across the detection resistor, and when abnormal voltage is detected (indicating relay contact fusion), the system feeds back this information to the control circuit, which then triggers an alarm and forces the compressor to stop. This feedback loop ensures that relay contact degradation or fusion does not compromise the shutdown function.

Inventive Principle:
Principle #23Feedback

2Device complexity

If the system relies solely on the pressure switch to stop the compressor, then the control system can be simpler, but misoperation may occur due to relay failures without detection

Engineering Contradiction:
Improvecontrol system complexityVSAvoidpressure switch state detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary detection circuit that acts as a verification layer between the pressure switch and the compressor power supply. This circuit includes a detection resistor in series with the compressor power supply line and a detection circuit that monitors the voltage across this resistor. The detection circuit accurately determines whether power has actually been cut off to the compressor by measuring the voltage signal, providing precise detection of the pressure switch's actual effect despite relay contact issues.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 stops the compressor when abnormal pressure is detected, preventing system damage and ensuring reliable operation by ensuring timely de-energization and preventing pressure from rising further, thus enhancing safety and reliability.

Implementation Method 1

a rectifier circuit (20), and a driving control circuit (30) which are sequentially connected

Methodology Applied
Scientific EffectRectification:

Data Source

PatentEP3936781B1Compressor driving device, compressor pressure protection method, and air conditioner
Publication Date: 2024.06.12 GD MIDEA HEATING & VENTILATING EQUIP CO LTD
  • EP3936781B1 patent drawingFigure 1~2
  • EP3936781B1 patent drawingFigure 3~4

AI summary

A compressor driving device, a compressor pressure protection method, and an air conditioner. The compressor driving device comprises a three-phase alternating current power supply input end, a relay module (10), a rectifier circuit (20), and a driving control circuit (30) which are sequentially connected; the rectifier circuit (20) is used for converting connected alternating current into direct current and then outputting the direct current to a direct current bus; the driving control circuit (30) is used for converting the direct current output by the direct current bus into compressor (COMP) driving power; a pressure switch (SW1) is used for measuring the pressure value in a refrigerating system, and when the measured pressure value is larger than a preset pressure threshold, disconnecting the power supply circuit of the relay module (10); the driving control circuit (30) is also used for detecting the on-off state of the pressure switch (SW1) and controlling the compressor (COMP) to stop working when the pressure switch (SW1) is switched off.