TIDUBE5A January   2022  – October 2022

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 TMS320F2800137
      2. 2.3.2 TMS320F280025C
      3. 2.3.3 TMS320F280039C
      4. 2.3.4 UCC28740
      5. 2.3.5 UCC27517
      6. 2.3.6 TLV9062
      7. 2.3.7 TLV76733
    4. 2.4 System Design Theory
      1. 2.4.1 Interleaved PFC
        1. 2.4.1.1 Full Bridge Diode Rectifier Rating
        2. 2.4.1.2 Inductor Ratings
        3. 2.4.1.3 AC Voltage Sensing
        4. 2.4.1.4 DC Link Voltage Sensing
        5. 2.4.1.5 Bus Current Sensing
        6. 2.4.1.6 DC Link Capacitor Rating
        7. 2.4.1.7 MOSFET Ratings
        8. 2.4.1.8 Diode Ratings
      2. 2.4.2 Three-Phase PMSM Drive
        1. 2.4.2.1 Field Oriented Control of PM Synchronous Motor
        2. 2.4.2.2 Sensorless Control of PM Synchronous Motor
          1. 2.4.2.2.1 Enhanced Sliding Mode Observer with Phase Locked Loop
            1. 2.4.2.2.1.1 Mathematical Model and FOC Structure of an IPMSM
            2. 2.4.2.2.1.2 Design of ESMO for the IPMSM
            3. 2.4.2.2.1.3 Rotor Position and Speed Estimation with PLL
        3. 2.4.2.3 Field Weakening (FW) and Maximum Torque Per Ampere (MTPA) Control
        4. 2.4.2.4 Compressor Drive with Automatic Vibration Compensation
        5. 2.4.2.5 Fan Drive with Flying Start
        6. 2.4.2.6 Hardware Prerequisites for Motor Drive
          1. 2.4.2.6.1 Motor Current Feedback
            1. 2.4.2.6.1.1 Current Sensing with Three-Shunt
            2. 2.4.2.6.1.2 Current Sensing with Single-Shunt
          2. 2.4.2.6.2 Motor Voltage Feedback
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Getting Started Hardware
      1. 3.1.1 Hardware Board Overview
      2. 3.1.2 Test Conditions
      3. 3.1.3 Test Equipment Required for Board Validation
      4. 3.1.4 Test Setup
    2. 3.2 Getting Started Firmware
      1. 3.2.1 Download and Install Software Required for Board Test
      2. 3.2.2 Opening Project Inside CCS
      3. 3.2.3 Project Structure
    3. 3.3 Test Procedure
      1. 3.3.1 Build Level 1: CPU and Board Setup
        1. 3.3.1.1 Start CCS and Open Project
        2. 3.3.1.2 Build and Load Project
        3. 3.3.1.3 Setup Debug Environment Windows
        4. 3.3.1.4 Run the Code
      2. 3.3.2 Build Level 2: Open Loop Check with ADC Feedback
        1. 3.3.2.1 Start CCS and Open Project
        2. 3.3.2.2 Build and Load Project
        3. 3.3.2.3 Setup Debug Environment Windows
        4. 3.3.2.4 Run the Code
      3. 3.3.3 Build Level 3: Closed Current Loop Check
        1. 3.3.3.1 Start CCS and Open Project
        2. 3.3.3.2 Build and Load Project
        3. 3.3.3.3 Setup Debug Environment Windows
        4. 3.3.3.4 Run the Code
      4. 3.3.4 Build Level 4: Full PFC and Motor Drive Control
        1. 3.3.4.1  Start CCS and Open Project
        2. 3.3.4.2  Build and Load Project
        3. 3.3.4.3  Setup Debug Environment Windows
        4. 3.3.4.4  Run the Code
        5. 3.3.4.5  Run the System
        6. 3.3.4.6  Tuning Motor Drive FOC Parameters
        7. 3.3.4.7  Tuning PFC Parameters
        8. 3.3.4.8  Tuning Field Weakening and MTPA Control Parameters
        9. 3.3.4.9  Tuning Flying Start Control Parameters
        10. 3.3.4.10 Tuning Vibration Compensation Parameters
        11. 3.3.4.11 Tuning Current Sensing Parameters
    4. 3.4 Test Results
      1. 3.4.1 Performance Data and Curves
      2. 3.4.2 Functional Waveforms
      3. 3.4.3 Transient Waveforms
      4. 3.4.4 MCU CPU Load, Memory and Peripherals Usage
        1. 3.4.4.1 CPU Load for Full Implementation
        2. 3.4.4.2 Memory Usage
        3. 3.4.4.3 Peripherals Usage
    5. 3.5 Migrate Firmware to a New Hardware Board
      1. 3.5.1 Configure the PWM, CMPSS, and ADC Modules
      2. 3.5.2 Setup Hardware Board Parameters
      3. 3.5.3 Configure Faults Protection Parameters
      4. 3.5.4 Setup Motor Electrical Parameters
      5. 3.5.5 Setup PFC Control Parameters
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 Bill of Materials
      3. 4.1.3 Altium Project
      4. 4.1.4 Gerber Files
      5. 4.1.5 PCB Layout Guidelines
    2. 4.2 Software Files
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  10. 5Terminology
  11. 6Revision History

2.4.1.6 DC Link Capacitor Rating

  • TIDM02010 uses aluminum electrolyte capacitor for DC link. Although polymer electrolytic capacitors with the significantly longer lifetime has proven its high reliability, it is not optimal choice when comes to high vibration environment like compressor outdoor unit. Unlike liquid electrolyte in aluminum electrolyte capacitor, polymer electrolyte capacitor cannot absorb vibration because of its solid polymer structure. To absorb high frequency component on DC link, metal film capacitor is also used in DC link. These caps are placed very close boost diode to reduce high frequency loop.
  • Capacitance Value Calculation
    • Value of DC link capacitor based on holdup charge
      Equation 10. C O U T ( M I N ) ≥ 2 × P O U T × 1 f L I N E V O U T 2   - V O U T 2 2
    • Value of DC link capacitor value based upon voltage ripple requirement
      Equation 11. C O U T ( M I N ) = 1 4 × P O U T V O U T × η × 0 . 637 V R I P P L E × 0 . 8 × π × f LINE
    • Capacitor Derating

      Actual capacitor value changes based upon factors like initial capacitor tolerance, temperature and aging. Consider 20% for each factor.

      Equation 12. C O U T = C O U T ( M I N ) ( 1 - η t o l e r a n c e ) × ( 1 - η t e m p ) × ( 1 - η a g i n g )
  • Capacitance Voltage Rating
    • Considering peak ripple voltage
      Equation 13. W V D C _ B U S _ C A P _ M I N   =   V D C B U S + ∆ V P P 2
    • Considering 10% safety margin for transient and overvoltage
Equation 14. WVDC_BUS_CAP = 1.1×WVDC_BUS_CAP_MIN
  • Capacitance Current RMS Value

    To estimate the capacitor RMS current is not straight forward and needs following steps.

    • Angular frequency is given by
      Equation 15. ω=2×π×fLINE
    • Number of iteration
      Equation 16. iteration=FSW_PFC2×FLINE
    • Value of one step in seconds:
      Equation 17. Step = 1fLINEIteration
    • Line voltage is sine function and can be determined by
      Equation 18. VIN(t)=2×VIN(RMS)×sinωt
    • Duty Ratio is also function of input voltage and can be calculated as
      Equation 19. Dt=VOUT - VIN(ωt)VOUT
    • With power factor correction, input current is also sine function
      Equation 20. IINt=2× POUTηSystem×VIN(MIN)×sinωt
      Equation 21. ICrms=1Iteration×∑n=1IterationIINn×Step2×12×(2-2×D(n×Step))-(2-2×D(n×Step))22
  • Capacitor ESR Rating
    Equation 22. ESRMAX≥VRIPPLE×0.2POUT×2VIN(MIN)×η