IPM Motor MTPA Trajectory Optimization via Particle Swarm

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Solution Overview

Problem

Current IPM motor control schemes for hybrid electric and battery electric vehicles face inefficiencies due to errors in parameter estimation, additional copper losses, noise, vibration, and computational intensity, as well as time-consuming offline methods and hardware requirements for optimizing maximum torque per ampere (MTPA) control.

Innovation Solution

The method employs particle swarm optimization to determine the maximum torque per ampere trajectory for IPM motors in real-time, eliminating the need for precise motor parameter estimation and avoiding additional current injections, thereby optimizing current phase angles and reducing computational burden.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If offline parameter estimation methods are used for MTPA control, then parameter accuracy may be improved, but control development time and calibration time increase significantly

Engineering Contradiction:
Improveparameter estimation accuracyVSAvoidcontrol development time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs self-calibration by automatically determining MTPA trajectory points through real-time optimization without requiring external parameter estimation tools or extensive offline calibration procedures. The motor controller itself executes the optimization algorithm using operational data to generate accurate MTPA control parameters.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces traditional mechanical/physical parameter estimation methods with a computational optimization approach. Instead of using offline experimental methods to determine motor parameters, the system uses real-time optimization algorithms to directly determine optimal current phase angles for MTPA control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If online MTPA schemes inject additional pulsating current signals for optimization, then control accuracy is improved, but copper losses, noise, vibration, and torque pulsation increase

Engineering Contradiction:
Improvecontrol accuracyVSAvoidcopper losses
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The invention extracts and eliminates the harmful additional current injection component from the MTPA optimization process. By removing this unnecessary pulsating current signal, the system achieves accurate MTPA control without the associated copper losses, noise, vibration, and torque pulsation that result from injecting optimization signals.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If derivative-based online optimized MTPA schemes are used, then control adaptability is improved, but the system may get stuck in local minima/maxima and efficiency decreases

Engineering Contradiction:
Improvecontrol adaptabilityVSAvoidoptimization reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent inverts the traditional derivative-based optimization approach by using a direct optimization method that searches for optimal solutions without relying on gradient information. This reversal of the optimization strategy prevents the system from getting trapped in local minima or maxima, ensuring reliable convergence to global optimal MTPA points while maintaining adaptability.

Inventive Principle:
Principle #13The other way round (Inversion)

4Measurement precision

If online parameter estimation techniques are implemented, then real-time control accuracy is improved, but computational burden increases and processor resources are consumed

Engineering Contradiction:
Improvereal-time control accuracyVSAvoidcomputational burden
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system extracts and removes the computationally intensive parameter estimation step from the real-time control loop. By eliminating the need for continuous online parameter estimation, the patent reduces processor burden and computational complexity while maintaining real-time control accuracy through direct optimization methods.

Inventive Principle:
Principle #2Taking out (Extraction)

5Measurement precision

If additional hardware filters are added for parameter estimation, then measurement accuracy is improved, but device complexity and control development time increase

Engineering Contradiction:
Improveparameter measurement accuracyVSAvoidhardware requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the requirement for additional hardware filters by using optimization methods that work directly with available sensor measurements. The system achieves accurate MTPA control without needing extra filtering hardware, thereby reducing device complexity and avoiding increased control development time.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS8593088B2Method and system for controlling an electric motor for a vehicle
Publication Date: 2013.11.26 FCA US LLC
  • US8593088B2 patent drawing
  • US8593088B2 patent drawing
  • US8593088B2 patent drawing

AI summary

A system and method for calibrating an interior permanent magnet (IPM) motor with an optimized maximum torque per ampere trajectory curve. The system and method use a real-time particle swarm technique that requires less known parameters than standard maximum torque per ampere trajectory techniques.