SLAU958A January   2025  – March 2025 MSPM0G3507

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Hardware Setup
    1. 2.1  EVM Hardware Setup
      1. 2.1.1 EVM Hardware Support
    2. 2.2  Peripheral Configurations for IPD Usage
    3. 2.3  Pin Configurations for PWM Outputs
    4. 2.4  Pin Configurations for ADC Currents
    5. 2.5  Pin Configurations for ADC Voltages
    6. 2.6  Pin Configurations for Faults
    7. 2.7  Pin Configurations for GPIO Output Functions
    8. 2.8  Pin Configurations for SPI Communication
    9. 2.9  Pin Configurations for UART Communication
    10. 2.10 External Connections for Evaluation Boards
  6. 3Software Setup
  7. 4GUI Setup
    1. 4.1 Serial Port Configuration
    2. 4.2 GUI Home Page
    3. 4.3 System Configurations
    4. 4.4 Register Map
    5. 4.5 Motor Tuning Page
    6. 4.6 Collateral Page
    7. 4.7 Loading and Saving Register Configurations
  8. 5Register Map
    1. 5.1 Register Map Page in GUI
    2. 5.2 User Control Registers (Base Address = 0x20200400h)
      1. 5.2.1 Speed Control Register (Offset = 0h) [Reset = 00000000h]
      2. 5.2.2 Algo Debug Control 1 Register (Offset = 4h) [Reset = 00000000h]
      3. 5.2.3 Algo Debug Control 2 Register (Offset = 8h) [Reset = 00000000h]
      4. 5.2.4 Algo Debug Control 3 Register (Offset = Ch) [Reset = 00000000h]
      5. 5.2.5 DAC Configuration Register (Offset = 10h) [Reset = 00000000h]
    3. 5.3 User Input Registers (Base Address = 0x20200000h)
      1. 5.3.1  SYSTEM_PARAMETERS (Offset = 0h)
      2. 5.3.2  ISD_CONFIG Register (Offset = 3Ch) [Reset = 00000000h]
      3. 5.3.3  MOTOR_STARTUP1 Register (Offset = 40h) [Reset = 00000000h]
      4. 5.3.4  MOTOR_STARTUP2 Register (Offset = 44h) [Reset = 00000000h]
      5. 5.3.5  CLOSED_LOOP1 Register (Offset = 48h) [Reset = 00000000h]
      6. 5.3.6  CLOSED_LOOP2 Register (Offset = 4Ch) [Reset = 00000000h]
      7. 5.3.7  FIELD_CTRL Register (Offset = 50h) [Reset = 00000000h]
      8. 5.3.8  FAULT_CONFIG1 Register (Offset = 54h) [Reset = 00000000h]
      9. 5.3.9  FAULT_CONFIG2 Register (Offset = 58h) [Reset = 00000000h]
      10. 5.3.10 MISC_ALGO Register (Offset = 5Ch) [Reset = 00000000h]
      11. 5.3.11 PIN_CONFIG Register (Offset = 60h) [Reset = 00000000h]
      12. 5.3.12 PERI_CONFIG Register (Offset = 64h) [Reset = 00000000h]
    4. 5.4 User Status Registers (Base Address = 0x20200430h)
  9. 6Basic Tuning
    1. 6.1 System Configuration Parameters
      1. 6.1.1 Configuring System Parameters From GUI
      2. 6.1.2 Motor Resistance in Milliohms (mΩ)
      3. 6.1.3 Motor Inductance in Microhenries (μH)
      4. 6.1.4 Saliency of IPMSM Motor
      5. 6.1.5 Motor BEMF Constant
      6. 6.1.6 Base Voltage (V)
      7. 6.1.7 Base Current (A)
      8. 6.1.8 Maximum Motor Electrical Speed (Hz)
      9. 6.1.9 Maximum Motor Power(W)
    2. 6.2 Control Configurations for Basic Motor Spinning
      1. 6.2.1 Basic Motor Startup
        1. 6.2.1.1 Disable ISD
        2. 6.2.1.2 Motor Start Option - Align
        3. 6.2.1.3 Motor Open Loop Ramp
        4. 6.2.1.4 Motor Open Loop Debug
      2. 6.2.2 Controller Configuration for Spinning the Motor in Closed Loop
        1. 6.2.2.1 BEMF estimation for Sensorless Rotor Position detection
          1. 6.2.2.1.1 Enhanced Sliding Mode Observer
          2. 6.2.2.1.2 Finite BEMF Estimation Based on Motor model
        2. 6.2.2.2 Rotor Position and Speed Estimation With PLL
        3. 6.2.2.3 PI Controller Tuning for Closed Loop Speed Control
          1. 6.2.2.3.1 Current Loop PI Tuning
          2. 6.2.2.3.2 Speed Controller Tuning
        4. 6.2.2.4 Testing for Successful Startup Into Closed Loop
    3. 6.3 Fault Handling
      1. 6.3.1 Abnormal BEMF Fault [ABN_BEMF]
      2. 6.3.2 Monitoring Power Supply Voltage Fluctuations for Voltage Out of Bound Faults
      3. 6.3.3 No Motor Fault [NO_MTR]
  10. 7Advanced Tuning
    1. 7.1 Control Configurations Tuning
      1. 7.1.1  Control Mode of Operation
        1. 7.1.1.1 Closed Loop Speed Control Mode
        2. 7.1.1.2 Closed Loop Power Control Mode
        3. 7.1.1.3 Closed Loop Torque Control Mode
        4. 7.1.1.4 Voltage Control Mode
      2. 7.1.2  Initial Speed Detection of the Motor for Reliable Motor Resynchronization
      3. 7.1.3  Unidirectional Motor Drive Detecting Backward Spin
      4. 7.1.4  Preventing Back Spin of Rotor During Startup
        1. 7.1.4.1 Option 1: IPD
        2. 7.1.4.2 Option 2: Slow First Cycle
      5. 7.1.5  Gradual and Smooth Start up Motion
      6. 7.1.6  Faster Startup Timing
        1. 7.1.6.1 Option 1: Initial Position Detection (IPD)
        2. 7.1.6.2 Option 2: Slow First Cycle
      7. 7.1.7  Stopping Motor Quickly
      8. 7.1.8  Flux Weakening: Operating Motor at Speeds Higher than Rated Speed
      9. 7.1.9  Maximum Torque Per Ampere : Improve Efficiency of IPMSM Motors
      10. 7.1.10 Preventing Supply Voltage Overshoot During Motor Stop.
      11. 7.1.11 Protecting the Power Supply
      12. 7.1.12 FOC Bandwidth Selection
  11. 8Hardware Configurations
    1. 8.1 Direction Configuration
    2. 8.2 Brake Configuration
    3. 8.3 Main.h Definitions
      1. 8.3.1 Sense Amplifier Configuration
      2. 8.3.2 Driver Propagation Delay
      3. 8.3.3 Driver Min On Time
      4. 8.3.4 Current Shunt Configuration Selection
        1. 8.3.4.1 Three Shunt Configurations
        2. 8.3.4.2 Dual Shunt Configuration
        3. 8.3.4.3 Single Shunt Configuration
      5. 8.3.5 CSA Offset Scaling Factor Selection
    4. 8.4 Real-Time Variable Tracking
  12. 9Revision History
6.2.2.1.1 Enhanced Sliding Mode Observer

Model-based BEMF estimation methods are used to achieve position sensorless control of the IPMSM drive system when the motor runs at middle or high speeds. The model methods estimates the rotor position by the back-EMF or the flux linkage model. The sliding mode observer is an observer-design method based on sliding mode control. The structure of the system is not fixed but purposefully changed according to the current state of the system, forcing the system to move according to the predetermined sliding mode trajectory. Advantages include fast response, strong robustness, and insensitivity to both parameter changes and disturbances.


Sliding Mode Observer based BEMF Estimation

Figure 6-13 Sliding Mode Observer based BEMF Estimation

In a digital control application, a time discrete equation of the SMO is needed. The Euler method is the appropriate way to transform to a time discrete observer. The time discrete system matrix of motor model is given in stationary reference frame is given as in Equation 11.

Equation 11. i ̂ α   n + 1 i ̂ β ( n + 1 )   =   F s m o i ̂ α   n i ̂ β ( n )   +   G s m o V α   n   -   e ̂ α   n   -   z α   n V β   n   -   e ̂ β   n   -     z β   n

where Fsmo and Gsmo are constants defined based on the Motor parameters as shown below.

Equation 12. F s m o   =   e - R L   ,   G s m o   =   1 R 1 - e - R L

z α   and z β are sliding mode components and are defined as:

Equation 13. z α   z β   =   K s l i d e s i g n ( i ̂ α   -   i α ) s i g n ( i ̂ β   -   i β )

where Kslide is the constant sliding mode gain designed by Lyapunov stability analysis. The Kslide value can be tuned using the System Parameters. Having higher Kslide tracks the sliding surface current faster but having very high Kslide leads to errors in BEMF estimation due to switching noise.

Below equation represents the time discrete form of filtered BEMF. Low pass filter removes the high frequency sliding mode output, where the cutoff frequency f c is usually chosen as the fundamental frequency of stator current. This introduces a phase shift of 45 degrees which is compensated from the estimated rotor position.

Equation 14. e ̂ α   n + 1 e ̂ β   n + 1   =   e ̂ α   n e ̂ β   n   +   2 π f c z α   n   -   e ̂ α   n z β   n   -   e ̂ β   n