TIDUF60 December   2023

 

  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 TMS320F2800137
      2. 2.3.2 MSPM0G1507
      3. 2.3.3 TMP6131
      4. 2.3.4 UCC28881
      5. 2.3.5 TPS54202
      6. 2.3.6 TLV9062
      7. 2.3.7 TLV74033
    4. 2.4 System Design Theory
      1. 2.4.1 Hardware Design
        1. 2.4.1.1 Modular Design
        2. 2.4.1.2 High-Voltage Buck Auxiliary Power Supply
        3. 2.4.1.3 DC Link Voltage Sensing
        4. 2.4.1.4 Motor Phase Voltage Sensing
        5. 2.4.1.5 Motor Phase Current Sensing
        6. 2.4.1.6 External Overcurrent Protection
        7. 2.4.1.7 Internal Overcurrent Protection for TMS320F2800F137
      2. 2.4.2 Three-Phase PMSM Drive
        1. 2.4.2.1 Field-Oriented Control of PM Synchronous Motor
          1. 2.4.2.1.1 Space Vector Definition and Projection
            1. 2.4.2.1.1.1 ( a ,   b ) ⇒ ( α , β ) Clarke Transformation
            2. 2.4.2.1.1.2 α , β ⇒ ( d ,   q ) Park Transformation
          2. 2.4.2.1.2 Basic Scheme of FOC for AC Motor
          3. 2.4.2.1.3 Rotor Flux Position
        2. 2.4.2.2 Sensorless Control of PM Synchronous Motor
          1. 2.4.2.2.1 Enhanced Sliding Mode Observer With Phase-Locked Loop
            1. 2.4.2.2.1.1 Mathematical Model and FOC Structure of an IPMSM
            2. 2.4.2.2.1.2 Design of ESMO for the IPMSM
            3. 2.4.2.2.1.3 Rotor Position and Speed Estimation With PLL
        3. 2.4.2.3 Field Weakening (FW) and Maximum Torque Per Ampere (MTPA) Control
        4. 2.4.2.4 Hardware Prerequisites for Motor Drive
          1. 2.4.2.4.1 Motor Current Feedback
            1. 2.4.2.4.1.1 Three-Shunt Current Sensing
            2. 2.4.2.4.1.2 Single-Shunt Current Sensing
          2. 2.4.2.4.2 Motor Voltage Feedback
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Getting Started Hardware
      1. 3.1.1 Hardware Board Overview
      2. 3.1.2 Test Conditions
      3. 3.1.3 Test Equipment Required for Board Validation
    2. 3.2 Getting Started GUI
      1. 3.2.1 Test Setup
      2. 3.2.2 Overview of GUI Software
      3. 3.2.3 Setup Serial Port
      4. 3.2.4 Motor Identification
      5. 3.2.5 Spin Motor
      6. 3.2.6 Motor Fault Status
      7. 3.2.7 Tune Control Parameters
      8. 3.2.8 Virtual Oscilloscope
    3. 3.3 Getting Started C2000 Firmware
      1. 3.3.1 Download and Install Software Required for Board Test
      2. 3.3.2 Opening Project Inside CCS
      3. 3.3.3 Project Structure
      4. 3.3.4 Test Procedure
        1. 3.3.4.1 Build Level 1: CPU and Board Setup
          1. 3.3.4.1.1 Start CCS and Open Project
          2. 3.3.4.1.2 Build and Load Project
          3. 3.3.4.1.3 Setup Debug Environment Windows
          4. 3.3.4.1.4 Run the Code
        2. 3.3.4.2 Build Level 2: Open-Loop Check With ADC Feedback
          1. 3.3.4.2.1 Start CCS and Open Project
          2. 3.3.4.2.2 Build and Load Project
          3. 3.3.4.2.3 Setup Debug Environment Windows
          4. 3.3.4.2.4 Run the Code
        3. 3.3.4.3 Build Level 3: Closed Current Loop Check
          1. 3.3.4.3.1 Start CCS and Open Project
          2. 3.3.4.3.2 Build and Load Project
          3. 3.3.4.3.3 Setup Debug Environment Windows
          4. 3.3.4.3.4 Run the Code
        4. 3.3.4.4 Build Level 4: Full Motor Drive Control
          1. 3.3.4.4.1 Start CCS and Open Project
          2. 3.3.4.4.2 Build and Load Project
          3. 3.3.4.4.3 Setup Debug Environment Windows
          4. 3.3.4.4.4 Run the Code
          5. 3.3.4.4.5 Tuning Motor Drive FOC Parameters
          6. 3.3.4.4.6 Tuning Field Weakening and MTPA Control Parameters
          7. 3.3.4.4.7 Tuning Current Sensing Parameters
    4. 3.4 Test Results
      1. 3.4.1 Load and Thermal Test
      2. 3.4.2 Overcurrent Protection by External Comparator
      3. 3.4.3 Overcurrent Protection by Internal CMPSS
    5. 3.5 Migrate Firmware to a New Hardware Board
      1. 3.5.1 Configure the PWM, CMPSS, and ADC Modules
      2. 3.5.2 Setup Hardware Board Parameters
      3. 3.5.3 Configure Faults Protection Parameters
      4. 3.5.4 Setup Motor Electrical Parameters
    6. 3.6 Getting Started MSPM0 Firmware
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 Bill of Materials
      3. 4.1.3 PCB Layout Recommendations
      4. 4.1.4 Altium Project
      5. 4.1.5 Gerber Files
    2. 4.2 Software Files
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author
2.4.2.1.3 Rotor Flux Position

Knowledge of the rotor flux position is the core of the FOC. In fact if there is an error in this variable the rotor flux is not aligned with the d-axis and isd and isq are incorrect flux and torque components of the stator current. Figure 2-13 shows the (a, b, c), (α, β) and (d, q) reference frames, and the correct position of the rotor flux, the stator current and stator voltage space vector that rotates with d, q reference at synchronous speed.

GUID-20210326-CA0I-FRBD-TGGV-LXT01LTKDS3S-low.svgFigure 2-13 Current, Voltage and Rotor Flux Space Vectors in the (d, q) Rotating Reference Frame

The measure of the rotor flux position is different when considering the synchronous or asynchronous motor:

  • In the synchronous machine the rotor speed is equal to the rotor flux speed. Then θ (rotor flux position) is directly measured by the position sensor or by integration of rotor speed.
  • In the asynchronous machine, the rotor speed is not equal to the rotor flux speed (there is a slip speed), then a particular method is needed to calculate θ. The basic method is the use of the current model which needs two equations of the motor model in d, q reference frame.

Theoretically, the FOC for the PMSM drive allows the motor torque to be controlled independently with the flux like DC motor operation. In other words, the torque and flux are decoupled from each other. The rotor position is required for variable transformation from stationary reference frame to synchronously rotating reference frame. As a result of this transformation (so called Park transformation), q-axis current is controlling torque while d-axis current is forced to zero. Therefore, the key module of this system is the estimation of rotor position using enhance Sliding-Mode Observer (eSMO) or FAST estimator.

Figure 2-14 shows the overall block diagram of sensorless FOC of fan PMSM using eSMO with flying start in this reference design.

Figure 2-15 shows the overall block diagram of sensorless FOC of compressor PMSM using eSMO with field weakening control (FWC) and maximum torque per ampere (MTPA) in this reference design.

Figure 2-16 shows the overall block diagram of sensorless FOC of fan PMSM using FAST with flying start in this reference design.

Figure 2-17 shows the overall block diagram of sensorless FOC of compressor PMSM using FAST with field weakening control (FWC) and maximum torque per ampere (MTPA) in this reference design.

GUID-20210301-CA0I-ZKN3-GRPG-SBBFHHQC74FG-low.svgFigure 2-14 Sensorless FOC of PMSM Using eSMO With Flying Start (FS)
GUID-20210301-CA0I-CKD8-XB4K-SNWW5CPJDNLN-low.svgFigure 2-15 Sensorless FOC of PMSM Using eSMO With FWC and MTPA
GUID-20210301-CA0I-6JV4-LJ9F-FBGR7SGCNWKZ-low.svgFigure 2-16 Sensorless FOC of PMSM Using FAST With Flying Start (FS)
GUID-20210301-CA0I-HGQV-GDJG-4B76STTRKTLT-low.svgFigure 2-17 Sensorless FOC of PMSM Using FAST With FWC and MTPA