Motor controller of air conditioner

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing motor controllers for air conditioners lack a simple method to detect errors, which can lead to malfunctions and damage to circuit elements, particularly due to the lack of effective insulation from high voltage DC terminals.

Innovation Solution

A motor controller design that includes a dc terminal signal generator to detect and generate a pulse-type dc terminal signal, while simultaneously insulating the DC terminal from the microcomputer, allowing for error detection and preventing damage by controlling the switching elements based on the detected voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the microcomputer directly monitors the DC terminal voltage, then the error detection capability is improved, but the risk of high voltage damage to the microcomputer increases

Engineering Contradiction:

Improveerror detection capabilityVSAvoidhigh voltage damage risk

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a DC terminal signal generator as an intermediary component between the DC terminal and the microcomputer. This generator converts the DC terminal voltage into a pulse-type signal that is safe for the microcomputer to process, while still enabling error detection. The intermediary isolates the microcomputer from direct exposure to high voltage, resolving the contradiction between detection capability and safety.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the DC terminal is insulated from the microcomputer, then the safety and stability are improved, but the direct detection of DC terminal voltage becomes difficult

Engineering Contradiction:

Improvesystem stabilityVSAvoidDC terminal voltage detection

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces direct electrical connection (mechanical/electrical system) with a signal conversion approach. The DC terminal signal generator converts the DC voltage into a pulse-type signal that can be safely transmitted to the microcomputer through insulation barriers. This substitution maintains detection capability while achieving the desired insulation for safety and stability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If a simple error detection method is implemented, then the device complexity is reduced, but the protection against high voltage damage may be insufficient

Engineering Contradiction:

Improveerror detection system complexityVSAvoidprotection against high voltage damage

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The DC terminal signal generator serves multiple functions simultaneously: it detects DC terminal voltage errors, provides high voltage insulation, generates safe pulse signals for the microcomputer, and enables error detection without complex circuitry. By making this single component multi-functional, the patent achieves both simplicity and reliable protection against high voltage damage.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

This solution enhances the stability of the motor controller by enabling the detection of errors and preventing high voltage exposure to the microcomputer, thereby reducing the risk of malfunctions and extending the lifespan of the motor controller components.

Implementation Method 1

a converter having at least one switching element for converter, the converter converting AC utility power into DC power by a switching operation of the switching element

Methodology Applied

Scientific EffectSwitching operation:

Implementation Method 2

an inverter having at least one switching element for inverter, the inverter converting the DC power into prescribed AC power by a switching operation of the switching element

Methodology Applied

Scientific EffectSwitching operation:

Implementation Method 3

a dc terminal signal generator detecting a dc terminal voltage that is applied across an dc terminal of the converter to sequentially generate a pulse type dc terminal signal

Methodology Applied

Scientific EffectVoltage detection:

Data Source

PatentEP2063526B1Motor controller of air conditioner

Publication Date: 2017.10.04 LG ELECTRONICS INC

Figure 1
Figure 2
Figure 3

AI summary

The present invention relates to a motor controller for air conditioner including a converter having at least one switching element for converter, the converter converting AC utility power into DC power by a switching operation of the switching element; an inverter having at least one switching element for inverter, the inverter converting the DC power into prescribed AC power by a switching operation of the switching element and driving a three-phase motor; a microcomputer outputting a converter switching control signal that controls the switching element for converter; and a dc terminal signal generator detecting a dc terminal voltage that is applied across an dc terminal of the converter to sequentially generate a pulse type dc terminal signal, and insulating the dc terminal from the microcomputer. The present invention may sequentially generate a dc terminal signal and simultaneously insulate the dc terminal from the microcomputer, thus making it possible to improve the stability of the motor controller.