TIDUBE5A January   2022  – October 2022

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 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 TMS320F280025C
      3. 2.3.3 TMS320F280039C
      4. 2.3.4 UCC28740
      5. 2.3.5 UCC27517
      6. 2.3.6 TLV9062
      7. 2.3.7 TLV76733
    4. 2.4 System Design Theory
      1. 2.4.1 Interleaved PFC
        1. 2.4.1.1 Full Bridge Diode Rectifier Rating
        2. 2.4.1.2 Inductor Ratings
        3. 2.4.1.3 AC Voltage Sensing
        4. 2.4.1.4 DC Link Voltage Sensing
        5. 2.4.1.5 Bus Current Sensing
        6. 2.4.1.6 DC Link Capacitor Rating
        7. 2.4.1.7 MOSFET Ratings
        8. 2.4.1.8 Diode Ratings
      2. 2.4.2 Three-Phase PMSM Drive
        1. 2.4.2.1 Field Oriented Control of PM Synchronous Motor
        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 Compressor Drive with Automatic Vibration Compensation
        5. 2.4.2.5 Fan Drive with Flying Start
        6. 2.4.2.6 Hardware Prerequisites for Motor Drive
          1. 2.4.2.6.1 Motor Current Feedback
            1. 2.4.2.6.1.1 Current Sensing with Three-Shunt
            2. 2.4.2.6.1.2 Current Sensing with Single-Shunt
          2. 2.4.2.6.2 Motor Voltage Feedback
  8. 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
      4. 3.1.4 Test Setup
    2. 3.2 Getting Started Firmware
      1. 3.2.1 Download and Install Software Required for Board Test
      2. 3.2.2 Opening Project Inside CCS
      3. 3.2.3 Project Structure
    3. 3.3 Test Procedure
      1. 3.3.1 Build Level 1: CPU and Board Setup
        1. 3.3.1.1 Start CCS and Open Project
        2. 3.3.1.2 Build and Load Project
        3. 3.3.1.3 Setup Debug Environment Windows
        4. 3.3.1.4 Run the Code
      2. 3.3.2 Build Level 2: Open Loop Check with ADC Feedback
        1. 3.3.2.1 Start CCS and Open Project
        2. 3.3.2.2 Build and Load Project
        3. 3.3.2.3 Setup Debug Environment Windows
        4. 3.3.2.4 Run the Code
      3. 3.3.3 Build Level 3: Closed Current Loop Check
        1. 3.3.3.1 Start CCS and Open Project
        2. 3.3.3.2 Build and Load Project
        3. 3.3.3.3 Setup Debug Environment Windows
        4. 3.3.3.4 Run the Code
      4. 3.3.4 Build Level 4: Full PFC and Motor Drive Control
        1. 3.3.4.1  Start CCS and Open Project
        2. 3.3.4.2  Build and Load Project
        3. 3.3.4.3  Setup Debug Environment Windows
        4. 3.3.4.4  Run the Code
        5. 3.3.4.5  Run the System
        6. 3.3.4.6  Tuning Motor Drive FOC Parameters
        7. 3.3.4.7  Tuning PFC Parameters
        8. 3.3.4.8  Tuning Field Weakening and MTPA Control Parameters
        9. 3.3.4.9  Tuning Flying Start Control Parameters
        10. 3.3.4.10 Tuning Vibration Compensation Parameters
        11. 3.3.4.11 Tuning Current Sensing Parameters
    4. 3.4 Test Results
      1. 3.4.1 Performance Data and Curves
      2. 3.4.2 Functional Waveforms
      3. 3.4.3 Transient Waveforms
      4. 3.4.4 MCU CPU Load, Memory and Peripherals Usage
        1. 3.4.4.1 CPU Load for Full Implementation
        2. 3.4.4.2 Memory Usage
        3. 3.4.4.3 Peripherals Usage
    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
      5. 3.5.5 Setup PFC Control Parameters
  9. 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 Altium Project
      4. 4.1.4 Gerber Files
      5. 4.1.5 PCB Layout Guidelines
    2. 4.2 Software Files
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  10. 5Terminology
  11. 6Revision History
2.4.2.6.1.2 Current Sensing with Single-Shunt

The single shunt current sensing technique measures the dc-link bus current and, with knowledge of the power FET switching states, reconstructs the three phase current of the motor. The detailed description of the single shunt technique is described in the application note Sensorless-FOC for PMSM With Single DC-Link Shunt (spract7).

On this reference board, to implement single shunt current sensing technique by removing two shunts and shorting the connection of the U/V/W ground of the power module as shown in Figure 2-33.

  1. Remove current shunt resistors R53, and R65, just keep a single shunt resistor R56 to sense the DC_link current for compressor drive.

  2. Use a thick wire to connect the NU, NV, and NW pins together.

Figure 2-33 Motor Current Sensing Circuit with Single-Shunt.
The DC-Link current is not bi-directional signal, so the DC current offset can be set to a minimum or maximum value to improve the ADC sampling range for the DC_link current as Figure 2-34. Change the R64 from 4.70k (OHM) to 47.5K (OHM)/1% resistor for the reference voltage.

Figure 2-34 DC Offset Reference from 3.3-V Input Circuit.
The transfer function of this current sampling circuit and the calculation for single shunt are the same as the three shunt.