JAJU873 August   2020

 

  1.   概要
  2.   リソース
  3.   特長
  4.   アプリケーション
  5.   5
  6. 1 System Description
    1. 1.1 Medical Respiratory Systems
    2. 1.2 Respirator System Components
    3. 1.3 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Brushless DC Motor (BLDC)
        1. 2.2.1.1 DRV8323RS BLDC Motor Driver Design Calculations
        2. 2.2.1.2 BLDC Motor Driver Circuit
      2. 2.2.2 Solenoid Valve Drivers
        1. 2.2.2.1 DRV8847 Solenoid Driver Design Calculations
        2. 2.2.2.2 Solenoid Driver Circuit
      3. 2.2.3 Power Tree Architecture
        1. 2.2.3.1 Input protection - overvoltage and reverse voltage
        2. 2.2.3.2 LM5122 Boost Design Calculations
        3. 2.2.3.3 LMR33630 Buck Design Calculations
        4. 2.2.3.4 Secondary Power Stage – TPS62840 3.3V Buck
        5. 2.2.3.5 Secondary Power Stage – TPS7A02 3.3V LDO
        6. 2.2.3.6 Power Tree Circuit
    3. 2.3 Highlighted Products
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware and Software Requirements
    2. 3.2 Test Setup
      1. 3.2.1 Hardware Configuration
      2. 3.2.2 Software Configuration
    3. 3.3 Test Results
      1. 3.3.1 Motor Test Result
      2. 3.3.2 Valve Test Result
      3. 3.3.3 Power Tree Test Result
      4. 3.3.4 Key Test Summary
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Documentation Support
    3. 4.3 サポート・リソース
    4. 4.4 Trademarks
  10. 5About the Author

3.3.1 Motor Test Result

The following motor tests were conducted:

  • Motor Identification
    • Wonsmart WS7040_24_V200
    • Boreasa C65MS1_L5
  • No-Load Step Response
    • Current Step Response
    • Speed Step Response (10kRPM to 40kRPM and 40kRPM to 10kRPM)

Tests were done at room temperature around 22°C to 23°C, with a PWM of 45 kHz. The current and speed controllers were set to 45 kHz and 3 kHz. The user control parameters are configured in the user.h file.

#define USER_PWM_FREQ_kHz                (45.0)
#define USER_NUM_CTRL_TICKS_PER_CURRENT_TICK   (1)
#define USER_NUM_CTRL_TICKS_PER_SPEED_TICK  (15)

Motor Identification

When identifying the motor parameters, the proj_lab02c from MotorWare was used. The following parameters were identified for the Wonsmart_WS7040_24_V200 motor:

#define USER_MOTOR_TYPE                 MOTOR_Type_Pm
#define USER_MOTOR_NUM_POLE_PAIRS       (1)
#define USER_MOTOR_Rs                   (0.653760076)             
#define USER_MOTOR_Ls_d                 (0.000252834143)         
#define USER_MOTOR_Ls_q                 (0.000252834143)
#define USER_MOTOR_RATED_FLUX           (0.0168186165)

The following parameters were identified for the Boreasa_C65MS1_L5 motor:

#define USER_MOTOR_TYPE MOTOR_Type_Pm
#define USER_MOTOR_NUM_POLE_PAIRS (1)
#define USER_MOTOR_Rs (0.348989993) 
#define USER_MOTOR_Ls_d (0.000173127264) 
#define USER_MOTOR_Ls_q (0.000173127264)
#define USER_MOTOR_RATED_FLUX (0.0160903856)

Once the motor parameters are determined from lab02c and saved to user.h, the user can proceed to lab05h for step response testing.

No-Load Step Response

When measuring the step reponse, proj_lab05h was used. The motors tested were Wonsmart_WS7040_24_V200 and Boreasa_C65MS1_L5.

Figure 3-15 shows the Wonsmart Id current controller PI step response.

GUID-20200804-CA0I-W7JG-LXDG-BHGCCCTXJDCH-low.gif Figure 3-15 Wonsmart Id Current Controller PI Step Response

Figure 3-16 shows the Wonsmart speed controller PI step response.

GUID-20200804-CA0I-VV6S-BNQD-KMTH5MVKBMD4-low.gif Figure 3-16 Wonsmart Speed Controller PI Step Response
Table 3-5 PI Controller Parameters to Generate No-load Step Responses
CONTROLLER KP KI
Current controller at 45 kHz 0.395 0.172
Speed controller at 3 kHz

12

0.08

Figure 3-17 shows the Boreasa Id current controller PI step response.

GUID-20200804-CA0I-HP8S-74BZ-9XCDMN6MBGGQ-low.gif Figure 3-17 Boreasa Id Current Controller PI Step Response

Figure 3-18 shows the Boreasa speed controller PI step response.

GUID-20200804-CA0I-RQGH-SCDF-DCDFLGMRGW9G-low.gif Figure 3-18 Boreasa Speed Controller PI Step Response
Table 3-6 PI Controller Parameters to Generate No-load Step Responses
CONTROLLER KP KI
Current controller at 45 kHz 0.27 0.134
Speed controller at 3 kHz 30 0.12

These PI values are optimized for this specific speed range. In reality, the designer may have multiple sets of PI values depending on the specific operation (for example, one set low speed and another set for high speed).