SLLA665 April   2025 MCF8315A , MCF8315C , MCF8315C-Q1 , MCF8315D , MCF8316A , MCF8316C-Q1 , MCF8316D , MCF8329A , MCF8329A-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Open Loop and Handoff Stage
  5. 2EEPROM Configurations Affecting Open Loop to Closed Loop Handoff
  6. 3Open Loop to Closed Loop Handoff Tuning
    1. 3.1 Experimental Way to Tune Open Loop and Handoff Stage
      1. 3.1.1 Step-1: Initial Configuration
      2. 3.1.2 Step-2: Tuning of Parameters In Case Handoff is not Proper
        1. 3.1.2.1 Tuning of OL_ILIMIT
        2. 3.1.2.2 Tuning of Open Loop Acceleration Co-Efficient A1
        3. 3.1.2.3 Tuning of Handoff Thresholds
      3. 3.1.3 Step-3: Tuning of Handoff Configurations
  7. 4Optimum Handoff
    1. 4.1 Open Loop Time With the Recommended Settings
    2. 4.2 Open Loop Time by Following Optimum Handoff Steps
  8. 5Summary
  9. 6References

3 Open Loop to Closed Loop Handoff Tuning

Tuning the open loop and handoff stage is a critical part in running a BLDC motor reliably in closed loop. The device needs to accurately sense motor back-emf and rotor position before transitioning to closed loop. For a smooth handoff, make sure that the following points are met.

  1. By the end of open loop, the motor back emf needs to be sufficient to accurately estimate motor speed and motor angle.
  2. By the end of open loop, motor speed needs to follow the internal speed reference, for smooth transition to close loop.
  3. After the handoff, the error in motor angle (theta) needs to be decreased appropriately.