TIDUF87 November   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Current and Voltage Controller
      2. 2.2.2 DC/DC Start-Up
      3. 2.2.3 High-Resolution PWM Generation
    3. 2.3 Highlighted Products
      1. 2.3.1 TMS320F28P650DK
      2. 2.3.2 ADS8588S
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Software Requirements
      1. 3.2.1 Opening the Project Inside Code Composer Studio
      2. 3.2.2 Project Structure
      3. 3.2.3 Software Flow Diagram
    3. 3.3 Test Setup
      1. 3.3.1 Hardware Setup to Tune the Current and Voltage Loop
      2. 3.3.2 Hardware Setup to Test Bidirectional Power Flow
      3. 3.3.3 Hardware Setup for Current and Voltage Calibration
    4. 3.4 Test Procedure
      1. 3.4.1 Lab Variables Definitions
      2. 3.4.2 Lab 1. Open-Loop Current Control Single Phase
        1. 3.4.2.1 Setting Software Options for Lab 1
        2. 3.4.2.2 Building and Loading the Project and Setting up Debug Environment
        3. 3.4.2.3 Running the Code
      3. 3.4.3 Lab 2. Closed Loop Current Control Single Phase
        1. 3.4.3.1 Setting Software Options for Lab 2
        2. 3.4.3.2 Building and Loading the Project and Setting up Debug Environment
        3. 3.4.3.3 Running the Code
      4. 3.4.4 Lab 3. Open Loop Voltage Control Single Channel
        1. 3.4.4.1 Setting Software Options for Lab 3
        2. 3.4.4.2 Building and Loading the Project and Setting up Debug Environment
        3. 3.4.4.3 Running the Code
      5. 3.4.5 Lab 4. Closed Loop Current and Voltage Control Single Channel
        1. 3.4.5.1 Setting Software Options for Lab 4
        2. 3.4.5.2 Building and Loading the Project and Setting up Debug Environment
        3. 3.4.5.3 Running the Code
      6. 3.4.6 Lab 5. Closed Loop Current and Voltage Control Four Channels
        1. 3.4.6.1 Setting Software Options for Lab 5
        2. 3.4.6.2 Building and Loading the Project and Setting up Debug Environment
        3. 3.4.6.3 Running the Code
      7. 3.4.7 Calibration
    5. 3.5 Test Results
      1. 3.5.1 Current Loop Load Regulation
      2. 3.5.2 Current Loop Linearity Test
      3. 3.5.3 Voltage Loop Linearity Test
      4. 3.5.4 DCM Start-Up
      5. 3.5.5 Bidirectional Current Switching Time
      6. 3.5.6 Thermal Performance
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author

2.2.3 High-Resolution PWM Generation

To generate high resolution, a C2000 with high-resolution PWM output capability is used. The high-resolution counter is capable of 150ps time step, which is equivalent to 15-bit resolution at 192kHz PWM frequency for a 100MHz CPU clock. Table 2-1 shows PWM resolution at different switching frequencies.

Table 2-1 C2000™ MCU Resolution for PWM and HRPWM
PWM
FREQUENCY		 REGULAR RESOLUTION (PWM) HIGH RESOLUTION PWM
100MHz EPWMCLK
(kHz) BITS % BITS %
20 12.3 0.02 18.1 0
50 11 0.05 16.8 0.001
100 10 0.1 15.8 0.002
150 9.5 0.15 15.2 0.003
200 9 0.2 14.8 0.004
250 8.6 0.25 14.4 0.005