SPM Motor Control Using Non-Iterative Current and Voltage Reference

Solution Overview

Problem

Existing control algorithms for surface-mounted permanent magnet (SPM) motors require iteration methods that increase processor load and computation time, which is undesirable in cost-sensitive applications.

Innovation Solution

A method and system for controlling SPM motors that determine a peak torque value, limit torque commands, and calculate optimized current and voltage vectors without iteration, using a processor to directly command the inverter for efficient motor control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If iteration methods are used to determine reference current and voltage values, then the control algorithm can be applied to IPM motor types, but computation time increases and processor load increases

Engineering Contradiction:

Improveapplicability to IPM motor typesVSAvoidcomputation time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent extracts and removes the iteration method from the control algorithm for SPM motors, keeping only the essential calculation steps. This eliminates the computationally intensive iterative process while preserving the core functionality of determining reference current and voltage values, thus reducing computation time without sacrificing adaptability to different motor types through parameter configuration.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the computational approach from iterative parameter adjustment to direct calculation using closed-form equations. By transforming the control algorithm to use non-iterative mathematical expressions for calculating reference currents and voltages, the system achieves the same control objectives for SPM motors without the time penalty of iteration methods.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If iteration methods are used to determine reference current and voltage values, then the control algorithm can be applied to IPM motor types, but processor load increases

Engineering Contradiction:

Improveapplicability to IPM motor typesVSAvoidprocessor load

Core Design Contradiction:

Adaptability or versatilityVSPower

Solution Approach 1:

The patent extracts and removes the iteration method from the control algorithm for SPM motors, keeping only the essential calculation steps. This eliminates the computationally intensive iterative process while preserving the core functionality of determining reference current and voltage values, thus reducing computation time without sacrificing adaptability to different motor types through parameter configuration.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the expensive (in terms of processor resources) iteration method with a simpler, more efficient direct calculation approach for SPM motors. This substitution uses less computational power and processing resources, allowing the use of less costly processors while maintaining control performance.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If iteration methods are used, then control accuracy can be maintained for various motor types, but computation time increases resulting in lower sampling rates

Engineering Contradiction:

Improvecontrol accuracyVSAvoidsampling rate

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent extracts and removes the iteration method from the control algorithm for SPM motors, keeping only the essential calculation steps. This eliminates the computationally intensive iterative process while preserving the core functionality of determining reference current and voltage values, thus reducing computation time without sacrificing adaptability to different motor types through parameter configuration.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary calculations of motor parameters and characteristics before the main control loop execution. By pre-computing certain values and using closed-form equations for reference current and voltage calculations, the system reduces the computational burden during real-time operation, enabling higher sampling rates while maintaining control accuracy.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20250350221A1Surface-mounted permanent magnet motor control using calculated reference current and voltage

Publication Date: 2025.11.13 STEERING SOLUTIONS IP HOLDING CORP

AI summary

Technical solutions are described for controlling a surface-mounted permanent magnet (SPM) motor, including: determining a peak torque value; determining a limited torque command based on a torque command and which does not exceed the peak torque value; determining, based on the limited torque command, an optimized current command; determining, based on the optimized current command, a reference voltage vector; and commanding, based on the reference voltage vector, an inverter to apply an output voltage to the SPM motor. Determining the reference voltage vector includes: calculating an optimized voltage command based on the optimized current command; determining a required d-axis current based on the optimized voltage command and based on a bridge voltage satisfying a supply voltage constraint; determining a reference d-axis current based on the required d-axis current; determining a reference current vector including the reference d-axis current; and calculating the reference voltage vector based on the reference current vector.