SLLU363 may   2023 MCF8315A

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Hardware and GUI Setup
      1. 1.1.1 Jumper Configuration
      2. 1.1.2 External Connections
      3. 1.1.3 Connecting to the GUI
        1. 1.1.3.1 Connect to computer
        2. 1.1.3.2 Connect to the GUI
        3. 1.1.3.3 Verify Hardware Connection
  5. 2Essential Controls
    1. 2.1 Recommended Default Values
    2. 2.2 Device and Pin Configuration
      1. 2.2.1 Speed Input Mode
    3. 2.3 Control Configuration - Motor Parameters
      1. 2.3.1 Maximum Motor Electrical Speed (Hz)
    4. 2.4 Control configuration - Closed Loop
      1. 2.4.1 Current Limit for Torque PI Loop
    5. 2.5 Testing for Successful Startup into Closed Loop
    6. 2.6 Fault Handling
      1. 2.6.1 MPET IPD Fault [MPET_IPD_Fault]
      2. 2.6.2 MPET BEMF Fault [MPET_BEMF_Fault]
      3. 2.6.3 Abnormal BEMF Fault [ABN_BEMF]
      4. 2.6.4 Lock Current Limit [LOCK_LIMIT]
      5. 2.6.5 Hardware lock Current Limit [HW_LOCK_LIMIT]
      6. 2.6.6 No Motor Fault [NO_MTR]
  6. 3Basic Controls
    1. 3.1 Device and Pin Configuration
      1. 3.1.1 Power Saver or Sleep Mode for Battery Operated Applications
      2. 3.1.2 Direction and Brake Pin Override
    2. 3.2 System Level Configuration
      1. 3.2.1 Tracking Motor Speed Feedback in Real Time
      2. 3.2.2 Improving Acoustic Performance
      3. 3.2.3 Protecting the Power supply
      4. 3.2.4 Monitoring Power Supply Voltage Fluctuations for Normal Motor Operation
    3. 3.3 Control Configurations
      1. 3.3.1  Motor Parameter Estimation to Minimize Motor Parameter Variation Effects
      2. 3.3.2  Initial Speed Detection of the Motor for Reliable Motor Resynchronization
      3. 3.3.3  Unidirectional Motor Drive Detecting Backward Spin
      4. 3.3.4  Preventing Back Spin of Rotor During Startup
      5. 3.3.5  Faster Startup Timing
      6. 3.3.6  Gradual and Smooth Start up Motion
      7. 3.3.7  Improving Speed Regulation
      8. 3.3.8  Stopping Motor Quickly
      9. 3.3.9  Preventing Supply Voltage Overshoot During Motor Stop.
      10. 3.3.10 Protecting Against Rotor Lock or Stall Condition
      11. 3.3.11 Maximizing Thermal Efficiency and Increasing Thermal Performance
      12. 3.3.12 Mitigating Electromagnetic Interference (EMI)
      13. 3.3.13 Faster deceleration

2.6.5 Hardware lock Current Limit [HW_LOCK_LIMIT]

This fault gets triggered when there is a spike in the phase current due to short circuit as shown in Figure 2-5. Short circuit can be due to phase to phase, phase to GND or Vm to GND short. Another reason to trigger this fault is incorrect speed loop and current loop PI controller gains.

GUID-250D28C8-9F80-46A3-8C3C-F023F6FE3F5A-low.png Figure 2-5 Phase Current Waveform Showing a Spike due to Short Circuit

Step 1: Program Speed loop Kp [SPD_LOOP_KP], Speed loop Ki [SPD_LOOP_KI], current loop Kp [CURR_LOOP_KP] and current loop Ki [CURR_LOOP_KI] to zero. This enables auto calculation of speed loop and current loop PI controller gains.

Step 2: If the fault still persists, check the continuity across phase to phase, phase to GND or Vm to GND to make sure there is no short across these terminals.