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

4 Optimum Handoff

Whenever we need optimum handoff (least time in open loop), use the following steps:

  1. For a proper handoff and to accommodate variations in motor phase resistance/phase inductance (due to temperature), the variables SPEED_REF_OPEN_LOOP and SPEED_FDBK on DAC needs to match for 30% of the open loop time.
  2. Set OL_ILIMIT to Rated peak phase current or ILIMIT.
  3. With OL_ACC_A2 = 0 (or the lowest setting available). Set OL_ACC_A1 to next higher value of OL_ACC_A1 = (MAX_SPEED/10)Hz/s. Verify whether handoff is proper or not. If the handoff is not proper, revert to the previous setting else set OL_ACC_A1 to the next higher value and continue this procedure.
  4. Now set OL_ACC_A1 at half of last successful handoff setting, and now try increasing the value of OL_ACC_A2, until we get a successful handoff.
  5. Set OPN_CL_HANDOFF_THR to the next value higher than 20%. Verify whether handoff is proper or not. If the handoff is not proper, revert to the previous setting else set OPN_CL_HANDOFF_THR to the next higher value and continue this procedure.