Motor Drive Control Using Software Comparison for PWM Generation
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Solution Overview
Problem
Traditional drive motor control units require a magnitude comparator, leading to increased costs due to the necessity of specialized hardware, limiting their use to general-purpose microcomputers.
Innovation Solution
A motor drive control apparatus and method that utilizes a comparison processing module, such as a comparison match comparator, to compare the magnetic pole position with computed switching angles, enabling the generation of PWM signals without the need for a magnitude comparator, allowing the use of general-purpose microcomputers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a magnitude comparator is used in the traditional drive motor control unit, then the PWM signal generation can be achieved, but the device complexity and cost increase due to specialized hardware requirements
Solution Approach 1:
The patent replaces the traditional magnitude comparator hardware with a software-based comparison processing module that runs on a general-purpose microcomputer. The comparison function is implemented through program instructions rather than dedicated electronic circuitry, substituting a mechanical/electrical system with a software-based solution. This allows the control unit to use standard microcomputers instead of specialized hardware, reducing device complexity and cost while maintaining PWM signal generation capability
Solution Approach 2:
The comparison processing module is designed to perform multiple functions within the PWM generation process. It not only compares the magnetic pole position with switching angles but also integrates with the overall control algorithm, current control, and voltage command generation. This multi-functional approach eliminates the need for separate dedicated comparator circuits, allowing a general-purpose microcomputer to handle specialized control functions
2Measurement precision
If a magnitude comparator is required, then accurate comparison of voltage phase angle can be achieved, but the ease of manufacture deteriorates due to limitation to specialized hardware
Solution Approach 1:
The patent replaces the magnitude comparator hardware with a software-based comparison processing module that runs on a general-purpose microcomputer. The comparison function is implemented through program instructions rather than dedicated electronic circuitry, substituting a mechanical/electrical system with a software-based solution. This allows the control unit to use standard microcomputers instead of specialized hardware, reducing device complexity and cost while maintaining PWM signal generation capability
Solution Approach 2:
The patent implements the comparison function through software code that replicates the functionality of a hardware magnitude comparator. The comparison processing module uses program instructions to perform the same logical comparison operation, creating a software copy of the hardware comparator's function. This approach allows accurate comparison to be achieved through software logic while using readily available general-purpose microcomputers
Data Source
AI summary
A general-purpose comparator can be used as a comparison processing module to reduce the costs of a motor drive control apparatus. The apparatus has an electric machine; a magnetic pole position computation processing module; a pattern generation processing module; a switching angle computation processing module which computes a switching angle where switching is done in a next control period based on a pulse pattern; a comparison processing module which compares the magnetic pole position with the computed switching angle to generate a comparison signal; and an on-off output processing module which generates a PWM signal based on the comparison signal indicative of the comparison result. In this case, because the magnetic pole position is compared with the computed switching angle to generate the PWM signal based on the comparison signal, a general-purpose comparator can be used as the comparison processing module.