TIDUF31A May   2023  – April 2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 MSPM0G1507
      2. 2.3.2 UCC28881
      3. 2.3.3 UCC27712
      4. 2.3.4 TLV9064
      5. 2.3.5 TPS54202
  9. 3System Design Theory
    1. 3.1  High-Voltage Buck Auxiliary Power Supply
    2. 3.2  DC Bus Voltage Sensing
    3. 3.3  Motor Drive Stage
    4. 3.4  Bypass Capacitors
    5. 3.5  Phase Current Sensing With Two or Three Shunt Resistors
    6. 3.6  Phase Current Sensing With a Single Shunt Resistor
    7. 3.7  Hall-Effect Sensor or QEI Interface for Sensored Motor Control
    8. 3.8  DAC for Software Debug
    9. 3.9  Overcurrent Protection
    10. 3.10 Overtemperature Protection
    11. 3.11 Isolated UART port
    12. 3.12 Inverter Peak Power Capability
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
      1. 4.1.1 Hardware Board Overview
      2. 4.1.2 Test Equipment for Board Validation
    2. 4.2 Software Requirements
    3. 4.3 Test Setup
    4. 4.4 Test Results
      1. 4.4.1 Auxiliary Power Supply Test
      2. 4.4.2 Current Open Loop Test
      3. 4.4.3 Overcurrent Protection Test
      4. 4.4.4 Motor Start-Up Sequence
      5. 4.4.5 Load Test
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author

4.4.4 Motor Start-Up Sequence

Figure 4-7 shows the start-up sequence waveform for a PMSM motor with a sensorless FOC algorithm. The sequence usually consists of three phases: align, open loop ramp-up, speed closed loop. Complete the following steps during aligning:

  1. Slowly increase aligning current to prevent any surge current
  2. Move to open loop ramp-up
  3. Ramp-up current can be set to meet the start load requirement
  4. The rotor position observer starts to work during ramp-up time
  5. Once the motor speed reaches the set point and the rotor angle error is small enough, then the software moves to closed speed and closed current loop

The following list of channels are presented in Figure 4-7.

  • CH1(Blue): Observed rotor angle
  • CH2 (Cyan): AC input voltage
  • CH3 (Purple): DC bus voltage
  • CH4 (Green): Current of phase U
GUID-20230504-SS0I-FXZM-KL97-KNPJQQTRRGRB-low.pngFigure 4-7 Motor Start-Up Sequence for PMSM With Senseless FOC Algorithm