Air conditioning apparatus

Solution Overview

Problem

Existing air conditioning apparatuses for vehicles face challenges in accurately estimating motor coil and compressor discharge temperatures, especially in abnormal high-temperature environments, leading to inadequate overheating protection due to reliance on indirect parameters and increased complexity and cost.

Innovation Solution

An air conditioning apparatus with an inverter-integrated electric compressor that includes a temperature detection unit for the semiconductor switching device, allowing for direct estimation of motor coil and compressor discharge temperatures using detected temperature, rotational speed, and motive force, enabling effective overheating protection without additional sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature sensors are installed at the compressor discharge and motor coil locations to directly detect temperatures, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvetemperature detection accuracyVSAvoidconfiguration complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces physical temperature sensors with a computational model that estimates temperatures using electrical parameters (current, voltage, frequency) and operational data (rotational speed, discharge pressure). This substitution eliminates the need for additional sensing hardware while achieving accurate temperature monitoring through mathematical calculations based on the relationship between electrical inputs and thermal outputs in the compressor and motor systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If temperature sensors are installed at the compressor discharge and motor coil locations to directly detect temperatures, then measurement precision is improved, but cost increases

Engineering Contradiction:

Improvetemperature detection accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces physical temperature sensors with a computational model that estimates temperatures using electrical parameters (current, voltage, frequency) and operational data (rotational speed, discharge pressure). This substitution eliminates the need for additional sensing hardware while achieving accurate temperature monitoring through mathematical calculations based on the relationship between electrical inputs and thermal outputs in the compressor and motor systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If estimation methods using indirect parameters are used to avoid additional sensors, then device complexity is reduced, but measurement precision deteriorates in abnormal high-temperature environments

Engineering Contradiction:

Improveconfiguration complexityVSAvoidtemperature estimation accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent incorporates feedback mechanisms where the estimated temperatures from electrical parameters are continuously monitored and used to adjust control decisions. The system compares estimated temperatures against threshold values and dynamically adjusts compressor operation, creating a closed-loop control system that maintains accuracy even in abnormal conditions by continuously adapting to changing thermal environments based on real-time electrical and operational data.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent utilizes multiple varying parameters including current, voltage, frequency, rotational speed, and discharge pressure to estimate temperatures. By monitoring changes in these parameters over time and using their relationships in estimation calculations, the system can detect abnormal thermal conditions that deviate from normal operating patterns, thereby maintaining estimation accuracy across different operating conditions without requiring direct temperature sensing.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9791196B2Air conditioning apparatus

Publication Date: 2017.10.17 MITSUBISHI HEAVY IND LTD

AI summary

Provided is an air conditioning apparatus that is capable of suppressing increases in volume and cost of the apparatus and performing more suitable overheating protection. An electric compressor is an inverter-integrated electric compressor integrally including a compressor, an electric motor that drives the compressor, and an inverter including a temperature sensor that detects the temperature in the vicinity of a semiconductor switching device, wherein a controller estimates a discharge temperature of the compressor on the basis of a correlation of respective pressure loading characteristics for the detected temperature of the inverter, for the rotational speed of the compressor, and for the motive force of the compressor in a refrigerating cycle.