TIDUF18A October   2022  – February 2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1 CLLLC System Description
    1. 1.1 Key System Specifications
  8. 2 CLLLC System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations and System Design Theory
      1. 2.2.1 Tank Design
        1. 2.2.1.1 Voltage Gain
        2. 2.2.1.2 Transformer Gain Ratio Design (NCLLLC)
        3. 2.2.1.3 Magnetizing Inductance Selection (Lm)
        4. 2.2.1.4 Resonant Inductor and Capacitor Selection (Lrp and Crp)
      2. 2.2.2 Current and Voltage Sensing
        1. 2.2.2.1 VPRIM Voltage Sensing
        2. 2.2.2.2 VSEC Voltage Sensing
        3. 2.2.2.3 ISEC Current Sensing
        4. 2.2.2.4 ISEC TANK and IPRIM TANK
        5. 2.2.2.5 IPRIM Current Sensing
        6. 2.2.2.6 Protection (CMPSS and X-Bar)
      3. 2.2.3 PWM Modulation
  9. 3 Totem Pole PFC System Description
    1. 3.1 Benefits of Totem-Pole Bridgeless PFC
    2. 3.2 Totem-Pole Bridgeless PFC Operation
    3. 3.3 Key System Specifications
    4. 3.4 System Overview
      1. 3.4.1 Block Diagram
    5. 3.5 System Design Theory
      1. 3.5.1 PWM
      2. 3.5.2 Current Loop Model
      3. 3.5.3 DC Bus Regulation Loop
      4. 3.5.4 Soft Start Around Zero-Crossing for Eliminating or Reducing Current Spike
      5. 3.5.5 Current Calculation
      6. 3.5.6 Inductor Calculation
      7. 3.5.7 Output Capacitor Calculation
      8. 3.5.8 Current and Voltage Sense
  10. 4 Highlighted Products
    1. 4.1 C2000 MCU TMS320F28003x
    2. 4.2 LMG352xR30-Q1
    3. 4.3 UCC21222-Q1
    4. 4.4 AMC3330-Q1
    5. 4.5 AMC3302-Q1
  11. 5 Hardware, Software, Testing Requirements, and Test Results
    1. 5.1 Required Hardware and Software
      1. 5.1.1 Hardware Settings
        1. 5.1.1.1 Control Card Settings
      2. 5.1.2 Software
        1. 5.1.2.1 Opening the Project Inside Code Composer Studio
        2. 5.1.2.2 Project Structure
    2. 5.2 Testing and Results
      1. 5.2.1 Test Setup (Initial)
      2. 5.2.2 CLLLC Test Procedure
        1. 5.2.2.1 Lab 1. Primary to Secondary Power Flow, Open Loop Check PWM Driver
        2. 5.2.2.2 Lab 2. Primary to Secondary Power Flow, Open Loop CheckPWM Driver and ADC with Protection, Resistive Load Connected on Secondary
          1. 5.2.2.2.1 Setting Software Options for Lab 2
          2. 5.2.2.2.2 Building and Loading the Project and Setting up Debug Environment
          3. 5.2.2.2.3 Using Real-time Emulation
          4. 5.2.2.2.4 Running the Code
          5. 5.2.2.2.5 Measure SFRA Plant for Voltage Loop
          6. 5.2.2.2.6 Verify Active Synchronous Rectification
          7. 5.2.2.2.7 Measure SFRA Plant for Current Loop
        3. 5.2.2.3 Lab 3. Primary to Secondary Power Flow, Closed Voltage Loop Check, With Resistive Load Connected on Secondary
          1. 5.2.2.3.1 Setting Software Options for Lab 3
          2. 5.2.2.3.2 Building and Loading the Project and Setting up Debug Environment
          3. 5.2.2.3.3 Running the Code
          4. 5.2.2.3.4 Measure SFRA for Closed Voltage Loop
        4. 5.2.2.4 Lab 4. Primary to Secondary Power Flow, Closed Current Loop Check, With Resistive Load Connected on Secondary
          1. 5.2.2.4.1 Setting Software Options for Lab 4
          2. 5.2.2.4.2 Building and Loading the Project and Setting up Debug
          3. 5.2.2.4.3 Running the Code
          4. 5.2.2.4.4 Measure SFRA for Closed Current Loop
        5. 5.2.2.5 Lab 5. Primary to Secondary Power Flow, Closed Current Loop Check, With Resistive Load Connected on Secondary in Parallel to a Voltage Source to Emulate a Battery Connection on Secondary Side
          1. 5.2.2.5.1 Setting Software Options for Lab 5
          2. 5.2.2.5.2 Designing Current Loop Compensator
          3. 5.2.2.5.3 Building and Loading the Project and Setting up Debug
          4. 5.2.2.5.4 Running the Code
          5. 5.2.2.5.5 Measure SFRA for Closed Current Loop in Battery Emulated Mode
      3. 5.2.3 TTPLPFC Test procedure
        1. 5.2.3.1 Lab 1: Open Loop, DC
          1. 5.2.3.1.1 Setting Software Options for BUILD 1
          2. 5.2.3.1.2 Building and Loading Project
          3. 5.2.3.1.3 Setup Debug Environment Windows
          4. 5.2.3.1.4 Using Real-Time Emulation
          5. 5.2.3.1.5 Running Code
        2. 5.2.3.2 Lab 2: Closed Current Loop DC
          1. 5.2.3.2.1 Setting Software Options for BUILD 2
          2. 5.2.3.2.2 Designing Current Loop Compensator
          3. 5.2.3.2.3 Building and Loading Project and Setting Up Debug
          4. 5.2.3.2.4 Running Code
        3. 5.2.3.3 Lab 3: Closed Current Loop, AC
          1. 5.2.3.3.1 Setting Software Options for Lab 3
          2. 5.2.3.3.2 Building and Loading Project and Setting Up Debug
          3. 5.2.3.3.3 Running Code
        4. 5.2.3.4 Lab 4: Closed Voltage and Current Loop
          1. 5.2.3.4.1 Setting Software Options for BUILD 4
          2. 5.2.3.4.2 Building and Loading Project and Setting up Debug
          3. 5.2.3.4.3 Running Code
      4. 5.2.4 Test Results
        1. 5.2.4.1 Efficiency
        2. 5.2.4.2 System Performance
        3. 5.2.4.3 Bode Plots
        4. 5.2.4.4 Efficiency and Regulation Data
        5. 5.2.4.5 Thermal Data
        6. 5.2.4.6 PFC Waveforms
        7. 5.2.4.7 CLLLC Waveforms
  12. 6 Design Files
    1. 6.1 Schematics
    2. 6.2 Bill of Materials
    3. 6.3 Altium Project
    4. 6.4 Gerber Files
  13. 7 Software Files
  14. 8 Related Documentation
    1. 8.1 Trademarks
  15. 9 Terminology
  16. 10About the Author
  17. 11Revision History
5.2.2.2.5 Measure SFRA Plant for Voltage Loop
  1. The SFRA is integrated in the software of this build to measure the plant response which can then be used to design a compensator. To run the SFRA, keep the project running, and navigate to <Install directory >\C2000Ware_DigitalPower_SDK_<version>\libraries\sfra\gui\SFRA_GUI.exe
  2. Select the options for the device on the SFRA GUI; for example, for F280039, select floating point. Click on setup connection. In the pop-up window, deselect the boot-on-connect option and select an appropriate COM port. Click OK. Return to the SFRA GUI and click Connect.
  3. The SFRA GUI will connect to the device. A SFRA sweep can now be started by clicking Start Sweep. The complete SFRA sweep will take a few minutes to finish. Activity can be monitored by seeing the progress bar on the SFRA GUI and also by checking the flashing of blue LED on the back of the control card, which indicates UART activity. Once complete, a graph with the measurement will appear, as shown in Figure 5-14. (Note that the open-loop measurement is not valid in the lab as the loop is not closed. The user must only refer to the plant measurement.)
GUID-87F0EEDD-F644-4D3B-8DB3-AA71A9460EC0-low.png Figure 5-14 SFRA Open Loop Plot for the Closed Voltage Loop (Vprim 400 V, Vsec 300 V, Power 1.972 kW, Fsw 500 kHz)

The Frequency Response Data is also saved in the project folder, under an SFRA Data Folder, and is time-stamped with the time of the SFRA run. SFRA can be run at different frequency set points to cover the range of operation of the system. A compensator will be designed using these measured plots in the next lab; therefore, remember this time stamp, or rename the SFRA.csv file to a convenient name that is easy to identify.

Repeat the analysis at different frequency points, the plant gain will be different at different frequency points, see Figure 5-15 for gain measured at 333kHz and see Figure 5-16 for gain measured at 680kHz. Hence a compensator needs to be chosen that will be stable across the frequency range of the converter. All the runs will be saved in CSV file and can then be imported into compensation designer to check stability across the range of operation.

GUID-34055FA9-676F-447F-8592-6A2BAE507630-low.pngFigure 5-15 SFRA Open Loop Plot for the Closed Voltage Loop (Vprim 400 V, Vsec 320 V, Power 2.174 kW, Fsw 333 kHz)
GUID-E100C3BF-F458-4C4E-969D-4DBFB33CF45D-low.pngFigure 5-16 SFRA Open Loop Plot for the Closed Voltage Loop (Vprim 400 V, Vsec 293 V, Power 1.828 kW, Fsw 680 kHz)