TIDUF56 January   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Terminology
    2. 1.2 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 TMS320F28P65x-Q1
      2. 2.3.2 DRV3255-Q1
      3. 2.3.3 LM25184-Q1
      4. 2.3.4 TCAN1044A-Q1
  9. 3System Design Theory
    1. 3.1 Three-Phase PMSM Drive
      1. 3.1.1 Field-Oriented Control of PM Synchronous Motor
        1. 3.1.1.1 Space Vector Definition and Projection
          1. 3.1.1.1.1 ( a ,   b ) ⇒ ( α , β ) Clarke Transformation
          2. 3.1.1.1.2 α , β ⇒ ( d ,   q ) Park Transformation
        2. 3.1.1.2 Basic Scheme of FOC for AC Motor
        3. 3.1.1.3 Rotor Flux Position
    2. 3.2 Field Weakening (FW) Control
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
      1. 4.1.1 Hardware Board Overview
      2. 4.1.2 Test Conditions
      3. 4.1.3 Test Equipment Required for Board Validation
    2. 4.2 Test Setup
      1. 4.2.1 Hardware Setup
      2. 4.2.2 Software Setup
        1. 4.2.2.1 Code Composer Studio™ Project
        2. 4.2.2.2 Software Structure
    3. 4.3 Test Procedure
      1. 4.3.1 Project Setup
      2. 4.3.2 Running the Application
    4. 4.4 Test Results
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
      3. 5.1.3 PCB Layout Recommendations
        1. 5.1.3.1 Layout Prints
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
3.1.1.1.2 α , β ⇒ ( d ,   q ) Park Transformation

This is the most important transformation in the FOC. In fact, this projection modifies a 2-phase orthogonal system (α, β) in the (d, q) rotating reference frame. Considering the d axis aligned with the rotor flux, Figure 3-5 shows the relationship for the current vector from the two reference frame.

GUID-20210322-CA0I-NS9S-LGXG-SSJHR5CCBTBW-low.svg Figure 3-5 Stator Current Space Vector in the d,q Rotating Reference Frame

The flux and torque components of the current vector are determined by Equation 5.

Equation 5. i s d = i s α cos θ + i s β sin θ i s q = - i s α sin θ + i s β cos θ

where

  • θ is the rotor flux position

These components depend on the current vector (α, β) components and on the rotor flux position; if the right rotor flux position is known then, by this projection, the d,q component becomes a constant. Two phase currents now turn into dc quantity (time-invariant). At this point the torque control becomes easier where constant isd (flux component) and isq (torque component) current components controlled independently.