TIDUEY0 November   2020

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Li-ion Battery Formation
    2. 1.2 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 High-Resolution PWM Generation
      2. 2.2.2 Feedback Controller
      3. 2.2.3 Multiphase Configuration
      4. 2.2.4 Current and Voltage Feedback
      5. 2.2.5 Delta-Sigma ADC Clock Frequency Tuning
      6. 2.2.6 Minimize Crosstalk Error With a Differential ADC
      7. 2.2.7 Overcurrent Protection
    3. 2.3 Highlighted Products
      1. 2.3.1 TMS320F280049
      2. 2.3.2 ADS131M08
      3. 2.3.3 INA821
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Software
    3. 3.3 Test Setup
    4. 3.4 Test Results
      1. 3.4.1 Constant Control Accuracy ADS131M08 Feedback
      2. 3.4.2 Constant Control Accuracy 12-bit ADC Feedback
      3. 3.4.3 Constant-Voltage Control Accuracy
      4. 3.4.4 CC, CV Transformation
      5. 3.4.5 Constant-Current Transient Response
      6. 3.4.6 Charge to Discharge Mode Transition
  9. 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 Support Resources
    4. 4.4 Trademarks
  10. 5About the Author

3.3 Test Setup

The following steps are used to setup the hardware and software

  1. Setup the hardware as shown in the test setup image in Figure 3-3

    GUID-20201020-CA0I-DGNT-JNHD-DHKW6LGDPX4B-low.gifFigure 3-3 Test Setup.

  2. Insert F280049 Control Card in the control card slot on TIDA-010086 board

  3. Turn on 12-V power supply and check bias power supplies (+10 V, +5 V, –5 V, +3.3 VA and +3.3 VD) on the TIDA-010086 board

  4. Open CCS software and install C2000WARE-DIGITALPOWER-SDK if not installed. C2000WARE-DIGITALPOWER-SDK can be installed from CCS Resource Explorer Window.

  5. Import TIDA-010086 code and re-build the project. Once the build is finished, click the debug button to load the code into C2000TM MCU.

  6. Run the setupdebugenv.js file in the project to automatically load the user variables in the expression window

  7. Set Enable = 1 to turn on the channel. The new current and voltage can be updated to Iref_A and Vref_V variables.

If it is desired to re-tune the whole control loop, it can be done in following steps using SFRA and compensation designer. See C2000 Software Frequency Response Analyzer (SFRA) Library and Compensation Designer in SDK Framework User's Guide for more information.

  • Enable the SFRA and set it up as shown in Figure 3-4 to extract constant-current open-loop plant model.

GUID-20201020-CA0I-Z74D-MHNC-H7R1HCJ4D91M-low.gifFigure 3-4 SFRA Setup for Plant Model Extraction.

  • Set the mode of operation to constant-current open loop and duty to about 2 to 5% such that output current is half of the rated current. Run SFRA to record plant data. Figure 3-5 shows plant frequency response for 10-mΩ output load.

GUID-20201020-CA0I-RLLV-PHRN-HXDTR6TKPCF4-low.pngFigure 3-5 Plant Frequency Response.

  • Open compensation designer and load the plant data. Tune the compensation and update in the code

GUID-20201020-CA0I-8JDM-9KJF-T7K8FPP4P9KV-low.pngFigure 3-6 Tuning CC Loop Using Compensation Designer.

  • Setup SFRA as shown in Figure 3-7 to verify closed loop stability

GUID-20201020-CA0I-7HWT-K4RB-FNVDZ4DDSTZP-low.gifFigure 3-7 SFRA Setup Closed-Loop CC Mode.

  • Run SFRA to capture the data. Figure 3-8 shows CC mode frequency response. The closed-loop bandwidth matches to compensation designer value.

GUID-20201020-CA0I-SB75-HLFV-5TLJQRBDLHF1-low.pngFigure 3-8 CC Mode Frequency Response.

  • Similar steps are followed to tune CV loop. Figure 3-9 and Figure 3-10 show CV mode SFRA setup in open and closed operation, respectively.

GUID-20201020-CA0I-CCXX-ZJLQ-KRMNHDKRPFLH-low.gifFigure 3-9 SFRA Setup Open-Loop CV Mode.

GUID-20201020-CA0I-4GMD-FRRQ-T9MJ3SLK6K1D-low.gifFigure 3-10 SFRA Setup Closed-Loop CV Mode.