Motor Drive Control for PMSM Temperature Adaptation

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Solution Overview

Problem

Permanent magnet synchronous motors face issues with temperature deviations affecting torque and risk of irreversible demagnetization due to the difficulty in directly detecting rotor temperature, which existing methods fail to adequately address.

Innovation Solution

A motor drive control device for a 3-phase 6-wire type permanent magnet synchronous motor that independently controls each phase by using a 0-axis current calculation and determination unit to estimate temperature and adjust current flow, ensuring torque stability and preventing demagnetization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the permanent magnet synchronous motor operates at extreme temperatures, then the motor can function in various environments, but the permanent magnet may cause irreversible demagnetization or torque may fall outside predetermined range

Engineering Contradiction:

Improveenvironmental adaptabilityVSAvoidmagnet stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The control device estimates the permanent magnet temperature before demagnetization occurs by analyzing the relationship between q-axis current and electromagnetic torque. This preliminary temperature estimation enables proactive adjustment of control parameters to prevent irreversible demagnetization, rather than reacting after damage occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the relationship between q-axis current and electromagnetic torque to estimate permanent magnet temperature in real-time. This feedback mechanism allows the control device to adjust control strategies dynamically based on temperature conditions, maintaining reliability across varying environmental temperatures.

Inventive Principle:

Principle #23Feedback

2Adaptability or versatility

If the permanent magnet synchronous motor operates at extreme temperatures, then the motor can function in various environments, but torque may fall outside predetermined range

Engineering Contradiction:

Improveenvironmental adaptabilityVSAvoidtorque consistency

Core Design Contradiction:

Adaptability or versatilityVSForce

Solution Approach 1:

The control device estimates permanent magnet temperature before torque deviation occurs by analyzing the relationship between q-axis current and electromagnetic torque. This enables proactive adjustment of control parameters to maintain torque within predetermined ranges, rather than reacting after torque degradation occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the relationship between q-axis current and electromagnetic torque to estimate permanent magnet temperature in real-time. This feedback mechanism allows the control device to adjust control strategies dynamically based on temperature conditions, maintaining torque consistency across varying environmental temperatures.

Inventive Principle:

Principle #23Feedback

3Device complexity

If the permanent magnet synchronous motor uses a 3-phase 3-wire type configuration, then the wiring is simpler, but independent phase control is not possible

Engineering Contradiction:

Improvewiring complexityVSAvoidphase control flexibility

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The control device is designed to work with both 3-phase 3-wire and 3-phase 6-wire configurations. By estimating permanent magnet temperature through the relationship between q-axis current and electromagnetic torque, the same control algorithm can be applied regardless of wiring type, enabling universal applicability while maintaining independent phase control capability where available.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Adaptability or versatility

If the permanent magnet synchronous motor uses a 3-phase 6-wire type configuration, then independent phase control is possible, but the device complexity increases

Engineering Contradiction:

Improvephase control flexibilityVSAvoidwiring complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses existing current and torque measurements to estimate permanent magnet temperature without requiring additional sensors or complex hardware. This self-service approach leverages data already available in the control system, avoiding increased device complexity despite the benefits of 6-wire configuration.

Inventive Principle:

Principle #25Self-service

Data Source

PatentEP3258591B1Motor drive control device

Publication Date: 2021.08.11 ASTEMO LTD

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Figure 2(a)~2(b)
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AI summary

Provided is a motor drive control device which is capable of properly driving and controlling a permanent magnet synchronous motor capable of independently controlling each phase in accordance with the temperature of the permanent magnet. A motor drive control device 500 is a device which drives and controls a permanent magnet synchronous motor 100 in which each phase is independently controlled, and includes a 0-axis current calculation unit 305 which calculates and outputs a 0-axis current iz on the basis of a motor current; a 0-axis current determination unit 306 which compares and determines a reference 0-axis current value izs which is the 0-axis current value when the temperature of a permanent magnet provided in the permanent magnet synchronous motor 100 is a reference temperature with the calculated 0-axis current iz; and a switching signal generation unit 301 which drives and controls inverters 210a, 210b, and 210c on the basis of the result of comparison determination of the 0-axis current determination unit 306.