Digital Motor Control Device for SPWM Signal Generation

Solution Overview

Problem

Conventional sinusoidal pulse-width modulation (SPWM) methods for motor control are complex and lack accuracy, making them inefficient for precise motor control.

Innovation Solution

A motor control device and method that includes a signal conversion unit, frequency multiplication unit, profile generation circuit, and frequency converter unit, utilizing digital signals and logic operations to generate a sinusoidal PWM signal for accurate motor control, which can be integrated into a driver IC or microcontroller unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional analog circuits are used for SPWM modulation, then the implementation is simple, but the structure becomes complex and control accuracy deteriorates

Engineering Contradiction:

Improveimplementation simplicityVSAvoidcircuit structure complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent replaces the conventional analog circuit system with a digital system using a microcontroller unit. The MCU generates PWM signals through digital processing of sinusoidal reference waves and triangular carrier waves, eliminating the need for complex analog comparison circuits while maintaining implementation simplicity and improving control accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operating parameters from analog continuous signals to digital discrete signals. By using digital representation of the sinusoidal reference wave and triangular carrier wave, the system achieves both structural simplification and improved accuracy through precise digital parameter control.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If conventional analog circuits are used for SPWM modulation, then the implementation is simple, but the control accuracy deteriorates

Engineering Contradiction:

Improveimplementation simplicityVSAvoidcontrol accuracy

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent replaces the conventional analog circuit system with a digital system using a microcontroller unit. The MCU generates PWM signals through digital processing of sinusoidal reference waves and triangular carrier waves, eliminating the need for complex analog comparison circuits while maintaining implementation simplicity and improving control accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operating parameters from analog continuous signals to digital discrete signals. By using digital representation of the sinusoidal reference wave and triangular carrier wave, the system achieves both structural simplification and improved accuracy through precise digital parameter control.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If digital SPWM methods are used for accurate motor control, then the control precision is improved, but the device complexity increases

Engineering Contradiction:

Improvecontrol accuracyVSAvoidcircuit structure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs a microcontroller unit that performs multiple functions: generating sinusoidal reference waves, generating triangular carrier waves, comparing the two waves, and outputting PWM signals. This multi-functional integration simplifies the overall device structure while maintaining high control accuracy through digital processing.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functions of reference wave generation, carrier wave generation, wave comparison, and PWM output into a single integrated microcontroller unit. This consolidation eliminates the need for separate analog circuits for each function, reducing overall system complexity while preserving digital control accuracy.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS8917048B2Motor control device and motor control method

Publication Date: 2014.12.23 DELTA ELECTRONICS INC(CN)

AI summary

A motor control device and a motor control method are disclosed herein, where the motor control device includes a signal conversion unit, a frequency multiplication unit, a profile generation circuit and a frequency converter unit. The signal conversion unit receives a rotation speed signal from a motor and converts the rotation speed signal into a digital signal. The frequency multiplication unit generates a frequency multiplication signal based on the digital signal. The profile generation circuit performs frequency division on the frequency multiplication signal to get a profile signal. The frequency converter unit generates a reference signal and compares the reference signal with the profile signal to output a motor control signal.