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

5.1.5 Incremental System Build

The system is gradually built up through various build levels verifying specific functionality at each level so that at the final level, the system is fully verified and complete in all aspects. Eight levels of incremental system build are designed to verify the various modules used in the system. Levels 1 through 5 build up to a FCL enabled position controlled servo drive. Level 6 helps to perform the frequency response analysis using SFRA. Levels 7 and 8 build up to a connected servo drive performing speed control or position control.

Table 5-1 and Table 5-2 summarizes the core functions integrated and tested at each build level as well as the cores used to perform the tasks in each of the incremental builds.

Table 5-1 Functions Verified in Each Incremental System Build
Buildlevel Cores Used Functional Integration / Verification
CPU1 CM
LEVEL 1 √ Basic PWM generation
LEVEL 2 √ Open loop control of motor / calibration of feedbacks
LEVEL 3 √ CURRENT MODE - Closing current loop using FCL library
LEVEL 4 √ SPEED MODE - Closing speed loop using inner FCL verified in LEVEL 3
LEVEL 5 √ POSITION MODE - Closing position loop using inner speed loop verified in LEVEL 4
LEVEL 6 √ SFRA ANALYSIS - Performing SFRA on current loop running motor in speed mode (LEVEL 4)
LEVEL 7 √ √ ECAT loop back to TwinCAT - No motor control involved
LEVEL 8 √ √ Fully connected servo drive using TwinCAT to control the motor in speed mode (LEVEL 4) or position mode (LEVEL 5)
Table 5-2 Functional Modules Used in Each Incremental System Build
Software Module Level 1 Level 2 Level 3 Level 4 Level 5 Level 6 Level 7 Level 8
PWM Generation √√ √ FCL lib FCL lib FCL lib FCL lib FCL lib
QEP Interface in CLA / T-format interface √√ √ √ √ √ √
FOC functions √√ √ √ √ √
SFRA functions √√
ECAT functions √√ √