Motor Control Apparatus Temperature Difference Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional motor control apparatuses fail to detect temperature abnormalities in power inverter circuits effectively, as they only consider absolute temperature thresholds, missing slight deviations that may not cause immediate destruction but can lead to performance issues over time.

Innovation Solution

A motor control apparatus with two pairs of winding sets and power inverter circuits, equipped with temperature sensors and a temperature difference calculation mechanism, determines temperature abnormalities based on system-to-system temperature differences, allowing for early detection of slight deviations and reducing current limiting values to prevent output decline and excessive load on normal systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If temperature abnormality is determined only by absolute temperature threshold, then the determination is simple, but slight abnormalities that deviate from desired condition cannot be detected

Engineering Contradiction:

Improvetemperature abnormality determination simplicityVSAvoidtemperature abnormality detection accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The temperature monitoring function is segmented into two independent systems (first system and second system), each with its own temperature sensor and controller. By comparing temperatures between these segmented systems, the patent detects abnormalities that would be invisible to a single absolute threshold system.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements feedback by continuously comparing the detection temperatures of the first and second systems. When a temperature difference exceeds a predetermined threshold, the system provides feedback to stop or reduce output of the affected system, enabling detection of relative abnormalities rather than relying solely on absolute temperature values.

Inventive Principle:

Principle #23Feedback

2Stability of the object's composition

If temperature sensors are provided in both power inverter circuits, then system symmetry is improved, but the ability to detect relative temperature differences is lost

Engineering Contradiction:

Improvesystem symmetryVSAvoidrelative temperature difference detection

Core Design Contradiction:

Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The patent uses feedback control by comparing temperatures from both symmetric systems. The controllers exchange temperature information and adjust system output based on the temperature difference, transforming the symmetric dual-system configuration into an active comparison mechanism that detects relative abnormalities.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

While the physical system remains symmetric with two identical power inverter circuits, the control logic introduces functional asymmetry by comparing temperatures and selectively controlling which system operates or reduces output based on the temperature difference, enabling abnormality detection through controlled asymmetry in the response.

Inventive Principle:

Principle #4Asymmetry

3Reliability

If the current limiting value is reduced to prevent element destruction, then element reliability is improved, but the output of the power inverter circuit decreases

Engineering Contradiction:

Improveelement reliabilityVSAvoidpower inverter circuit output

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent dynamically adjusts the current limiting value based on real-time temperature conditions. When temperature difference indicates abnormality, the system reduces current limiting to prevent element destruction. When temperature is normal, the system operates at full current capacity, making the current limit dynamic rather than fixed to maintain both reliability and productivity.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the current limiting parameter based on temperature differential feedback. The current limit is adjusted from a fixed value to a variable parameter that responds to thermal conditions, allowing the system to optimize between element protection and output performance based on actual operating conditions.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9231465B2Motor control apparatus

Publication Date: 2016.01.05 DENSO CORP

AI summary

A motor control apparatus controlling a driving of a motor having two pairs of winding sets is provided. The motor control apparatus includes a current command value calculation portion, a first system, a second system, and a temperature difference calculation portion. The first system includes a first power inverter circuit, a first temperature sensor, a first current limit setting portion, and a first controller. The second system includes a second power inverter circuit, a second temperature sensor, a second current limit setting portion, and a second controller. One of the first controller and the second controller stops a driving of one of the first power inverter circuit and the second power inverter circuit or reduces the current limiting value of this.