SPRACM9B June   2019  – November 2020 TMS320F28384D , TMS320F28384S , TMS320F28386D , TMS320F28386S , TMS320F28388D , TMS320F28388S , TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DH-Q1 , TMS320F28P659DK-Q1 , TMS320F28P659SH-Q1

 

  1.   Trademarks
  2. 1 Introduction
    1. 1.1 Acronyms Used in This Document
  3. 2 Benefits of the TMS320F2838x MCU for High-Bandwidth Current Loop
  4. 3 Current Loops in Servo Drives
  5. 4 Outline of the Fast Current Loop Library
  6. 5 Fast Current Loop Evaluation
    1. 5.1 Evaluation Setup
      1. 5.1.1 Hardware
      2. 5.1.2 Software
      3. 5.1.3 FCL With T-Format Type Position Encoder
        1. 5.1.3.1 Connecting T-Format Encoder to IDDK
        2. 5.1.3.2 T-Format Interface Software
        3. 5.1.3.3 T-Format Encoder Latency Considerations
      4. 5.1.4 SDFM
      5. 5.1.5 Incremental System Build
  7. 6 Incremental Build Level 1
    1. 6.1 SVGEN Test
    2. 6.2 Testing SVGEN With DACs
    3. 6.3 Inverter Functionality Verification
  8. 7 Incremental Build Level 2
    1. 7.1 Setting the Overcurrent Limit in the Software
    2. 7.2 Current Sense Method
    3. 7.3 Voltage Sense Method
    4. 7.4 Setting Current Regulator Limits
    5. 7.5 Verification of Current Sense
    6. 7.6 Position Encoder Feedback
      1. 7.6.1 Speed Observer and Position Estimator
      2. 7.6.2 Verification of Position Encoder Orientation
  9. 8 Incremental Build Level 3
    1. 8.1 Observation One – PWM Update Latency
      1. 8.1.1 From the Expressions Window
      2. 8.1.2 From the Scope Plot
  10. 9 Incremental Build Level 4
    1. 9.1 Observation
  11. 10Incremental Build Level 5
  12. 11Incremental Build Level 6
    1. 11.1 Integrating SFRA Library
    2. 11.2 Initial Setup Before Starting SFRA
    3. 11.3 SFRA GUIs
    4. 11.4 Setting Up the GUIs to Connect to Target Platform
    5. 11.5 Running the SFRA GUIs
    6. 11.6 Influence of Current Feedback SNR
    7. 11.7 Inferences
      1. 11.7.1 Bandwidth Determination From Closed Loop Plot
      2. 11.7.2 Phase Margin Determination From Open Loop Plot
      3. 11.7.3 Maximum Modulation Index Determination From PWM Update Time
      4. 11.7.4 Voltage Decoupling in Current Loop
    8. 11.8 Phase Margin vs Gain Crossover Frequency
  13. 12Incremental Build Level 7
    1. 12.1 Run the Code on CPU1 to Allocate ECAT to CM
    2. 12.2 Run the Code on CM to Setup ECAT
    3. 12.3 Setup TwinCAT
    4. 12.4 Scanning for EtherCAT Devices via TwinCAT
    5. 12.5 Program ControlCard EEPROM for ESC
    6. 12.6 Running the Application
  14. 13Incremental Build Level 8
    1. 13.1 Run the Code on CPU1 to Allocate ECAT to CM
    2. 13.2 Run the Code on CM to Setup ECAT
    3. 13.3 Running the Application
  15. 14References
  16. 15Revision History

7 Incremental Build Level 2

Assuming build level 1 is completed successfully, this section verifies the overcurrent protection limits of the inverter and QEP interface running out of the CLA. In this build, the motor is run in open loop.

The motor can be connected to the HVDMC board because the PWM signals are successfully proven through the incremental build level 1.

  1. Open fcl_f2838x_tmdxiddk_settings_cpu1.h and select the level 2 incremental build option by setting the BUILDLEVEL to FCL_LEVEL2 (#define BUILDLEVEL FCL_LEVEL2).
  2. Select CURRENT_SENSE to LEM_CURRENT_SENSE
  3. Select POSITION_ENCODER to QEP_POS_ENCODER or T_FORMAT_ENCODER depending on the encoder coupled to motor.
  4. Right-click on the project name and click Rebuild Project.
  5. When the build is complete, click Debug, reset the CPU, restart, enable real-time mode, and run.

    Figure 7-1 shows the level 2 block diagram.

    GUID-E51A2D1B-A40B-4029-A5D9-D30B72FF2DF7-low.gif Figure 7-1 Level 2 Block Diagram
  6. Set enableFlag to 1 in the watch window. The variable named isrTicker is incrementally increased as shown in the Expressions window to confirm the interrupt is working properly. Now set the variable named runMotor to MOTOR_RUN; the motor starts spinning after a few seconds if enough voltage is applied to the DC-Bus.
    In the software, the key variables to be adjusted are same as in previous level and are given again below for reference.
    1. speedRef: for changing the rotor speed in per-unit
    2. VdTesting: for changing the d-axis voltage in per-unit
    3. VqTesting: for changing the q-axis voltage in per-unit

    During the open loop tests, VqTesting, speedRef, and DC bus voltages must be adjusted carefully for PM motors so that the generated Bemf is lower than the average voltage applied to motor winding. This adjustment prevents the motor from stalling or vibrating.