Running State | Motorola M68HC08 guide

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

Software Design

State Diagram

The output compare function is used to synchronize initiating the dc-bus current sampling with the PWM cycle, and also for the commutation timing.

Error Handler

If the BLDC motor is controlled properly, commutation events must be locked to the back-EMF zero crossing feedback. When that feedback is lost, commutation time is derived from previous commutation events. If feedback does not recover during a defined number of commutations (constant — C_MaxErr), then the situation is evaluated as irrecoverable commutation error, and the fault state is entered.

Measurement Handler

The measurement handler assures that the measurement process is done in the right order. The dc-bus voltage, speed command, and temperature are scanned sequentially. After the state has run three times, all the values for dc-bus current, dc-bus voltage, speed input, and temperature are updated. dc-bus current is scanned with a constant time period in the current measurement ISR, but the over-current condition is evaluated in the main software loop. After a defined number (I_OVC_Cnt) of successive over-current events, the control flow enters into the fault state.

5.5.6 Running State

The BLDC motor is run with regular feedback. The speed controller is used to control the motor speed by changing the value of PWM duty cycle. Figure 5-11shows the state transitions.

Measurements Handler

Explained in 5.5.5 Back-EMF Acquisition State.

Service of Commutation

Explained in 5.5.5 Back-EMF Acquisition State.

Service of Received Back-EMF Zero Crossing

DRM028 — Rev 0		Designer Reference Manual

MOTOROLA	Software Design	99
	For More Information On This Product,
	Go to: www.freescale.com

Image 99

Motorola M68HC08 Running State, Explained in 5.5.5 Back-EMF Acquisition State, Service of Received Back-EMF Zero Crossing

Contents

Freescale Semiconductor, Inc M68HC08 For More Information On This Product Designer Reference Manual Rev Sensorless Bldc Motor Control Using MC68HC908MR32 Revision history List of Sections List of Sections Table of Contents Table of Contents Title List of Figures List of Figures List of Tables List of Tables Application Functionality ContentsBenefits of the Solution Introduction Introduction System Concept System Description System Description System Specification Software Specifications Software SpecificationSoftware written in C language specifications are listed Software parameter tuning to a customer motor High-Voltage Hardware Set Specification Hardware and Drive Specifications Motor -Brake Set High Voltage Hardware Set Specifications Low-Voltage Evaluation Hardware Set Specification Low Voltage Evaluation Hardware Set SpecificationsLow-Voltage Hardware Set Specification Low Voltage Hardware Set Specifications Bldc Motor Control Brushless DC Motor Control TheoryBldc Motor Targeted by This Application Semiconductor, Inc Bldc Motor Control Brushless DC Motor Control Theory Bldc Motor Back EMF and Magnetic Flux Why Sensorless Control? 2 3-Phase Bldc Power Stage Power Stage Motor Topology Indirect Back EMF Sensing Stator Winding Equations Same expressions can also be found for phase a and B Effect of Mutual Inductance Phase Voltage Waveform Mutual Inductance Effect Detail of Mutual Inductance Effect Effect of Mutual Phase Capacitance Mutual Capacitance Model 10. Distributed Back-EMF by Unbalanced Capacity Coupling 11. Balanced Capacity Coupling Back-EMF Sensing Circuit Inc Used Control Technique Sensorless Commutation ControlAlignment Starting Back-EMF Acquisition Running Alignment 14. Commutation Control Stages Running 15. Alignment Freescale Semiconductor, Inc Commutation time calculation is shown in Figure Running Commutation Time Calculation 17. Bldc Commutation Time with Zero Crossing Sensing Service of received back-EMF zero crossing Where Starting Back-EMF Acquisition Freescale Semiconductor, Inc 18. Vectors of Magnetic Fields 19. Back-EMF at Start Up Starting Commutation Time Calculation Running Commutation Time Calculation, but the followingComputation coefficients are different Application Control Speed ControlPC Master Software PC Master Software Communication Commands Communication with PC Master Software Specifications Name Type Representing Description Range PC Master Software API Variables BIT6 Reserved MotorStatusDef, FailureDef BIT2 Reserved SpeedRangeMaxRPM*PerSpeedMAXRange/PerZCrosFltT2 PerSpeedMAXRange and zero crossing period PerZCrosFltT2 Freescale Semiconductor, Inc For High-Voltage Hardware Set cofiguration System Configuration and DocumentationHardware Design MC68HC908MR32 Control Board Components will describe the individual boards For Low-Voltage Evaluation Motor Hardware Set configurationEVM Motor Board Phase Low Voltage EVM Bldc Motor Low-Voltage Hardware Set configuration High-Voltage Hardware System Configuration High-Voltage Hardware Set Configuration Described in MC68HC908MR32 Control Board User’s Manual Motorola document order numberSee References Low-Voltage Evaluation Motor Hardware System Configuration Low-Voltage Evaluation Motor Hardware Set Configuration System configuration for low-voltage hardware set is shown Low-Voltage Hardware Set Configuration Low-Voltage Hardware System Configuration All HW Sets Components References1 MC68HC908MR32 Control Board Electrical characteristics in -1apply to operation at 25C 4shows a block diagram of the board’s circuitry Electrical Characteristics of Control Board 1 3-Phase AC/BLDC High Voltage Power StageHigh-Voltage Hardware Set Components Phase AC High Voltage Power Stage Optoisolation Board Electrical Characteristics of Power Stage Electrical Characteristics Electrical Characteristics of the Optoisolation Board 3 3-phase Bldc High Voltage Motor with Motor Brake Low-Voltage Evaluation Motor Hardware Set ComponentsEVM Motor Board Characteristics of the Bldc motor Electrical Characteristics of the EVM Motor BoardElectrical Characteristics of the EVM Motor Board 2 3-phase Low Voltage EVM Bldc Motor Low-Voltage Hardware Set Components 1 3-Ph AC/BLDC Low Voltage Power Stage Block Diagram Section 2 3-phase Bldc Low Voltage Motor with Motor Brake Data Flow Data Flow Main Software Flowchart State DiagramSoftware Design Introduction Software Variables and Defined Constants Important system variables are listed in TableSoftware Variables Start/Stop Switch Reading and Start/Stop Decision Sys3DefProcess Measurement Process Back, EMF Zero Crossing Sensing Main Data Flow Part1 Process Fault Control Fault Stop Freescale Semiconductor, Inc Main Data Flow Part 2 Alignment, Starting Closed Loop Control System Process Desired Speed Setting Processes Commutation and Zero Crossing Preset and Set Bldc Speed Control and CalculationProcess Alignment Control Bldc Commutation and Zero Crossing Selection Main Software Flowchart Main Software Flowchart Freescale Semiconductor, Inc Main Software Flowchart Main Software Loop Freescale Semiconductor, Inc Freescale Semiconductor, Inc Software Flowchart Interrupts State Diagram Application State Transitions Stand-By State diagram for this software is shown in FigureInitialize MCU Initialize Application Freescale Semiconductor, Inc Stand-by State Align State Starting Commutation Time Calculation Freescale Semiconductor, Inc 10. Back-EMF Acquisition Service of Commutation SetCommutation Time Calculation Service of Received Back-EMF Zero Crossing Running StateExplained in 5.5.5 Back-EMF Acquisition State Over Current 11. Running State Stop State 12. Stop State Fault State Software files and structure are described in section Implementation NotesSee Figure Software Files Preset Bldc Commutation and Bemf Zero Crossing Selection Bldc Commutation and Zero Crossing SelectionSet Bldc Commutation and Bemf Zero Crossing Selection PWMValMax = DUTYPWMMAX*MCPWMMODULUS Bldc Speed Control and CalculationDesired Speed Calculation PWM Duty Cycle Timer Timers Function TIMACh3Int Designer Reference Manual DRM028 Rev 108 Software Design Motor’s nominal speed User GuideApplication Suitability Guide Minimal Application Speed Maximal Application Speed Voltage Closed LoopMotor Suitability Mutual Inductance Designer Reference Manual DRM028 Rev 112 User Guide Application Hardware and Software Configuration Hardware ConfigurationHardware setups are shown in -1, -2, Low-Voltage Evaluation Motor Hardware Set Configuration High-Voltage Hardware Set Configuration Low-Voltage Hardware Set Configuration Controller Board Settings EVM Board Settings EVM board settings are the same for all hardware platformsSoftware Setup Application HC08 Software Files \bldczerocros08MR32\sources\bldc08.c, main program Application PC Master Software Control Files Software Execution BuildExecute from Evaluation Board Application Control When the software is built, the S-record fileExecute from Pre-programmed MCU Bldczerocros08mr32MMDS.sx is generated PC Master Software Remote Operating Mode Manual Operating Mode PC Master Software Control Window For More Information On This Product Tuning for Customer Motor User Guide Tuning for Customer Motor Follow-up for Software Customizing to Customer Motor Follow-up for Advanced Software Customizing Start the PC master software parameters tuning application To have PC master software installed on your PC computer 11. PC Master Software Parameters Tuning Control Window Software Parameters Setting Follow-up Labels in the File const.h Example of Software Customizing to Hardware Software Customizing to Power StageParameters File Selection \bldczerocros08MR32\sources\constcustlv.h, definitions for Voltage Setting Hardware Customizing Current Setting Hardware CustomizingRange 0,infinity Modified maximal measurable voltage is 55 V, so set Example of Software Customizing to Hardware Range 0,VOLTRANGEMAX Software Customizing to Motor Voltage and Current SettingsMaximal and Minimal Voltage Limits Setting Detailed description starts here Range 0,CURRENTRANGEMAXA Maximal and Minimal Current Limits Setting Alignment Current and Current Regulator Setting Current during alignment state before motor starts ΑRange 0,8 Parameters Tuning with PC Master Software Project File Set constcustx.hFrom Evaluation Board 12. PC Master Software Current Parameters Tuning Window Designer Reference Manual DRM028 Rev 142 User Guide MUSTCHANGEEXPERnn in file constcustx.h Commutation time period to discharge coil current ∝s Commutation Parameters Start-up Constants and Maximal Commutation Period Start-up Period Maximal commutation period limit ∝sRange -128,127 Ensure Percmtstartus =PERCMTMAXUS /2 Alignment Current and Current Regulator Setting 6.5.4.3Constcustx.h Constcustx.h Set #define Percmtstartus in constcustx.h Constcustx.h file #define Speedpiregigain 13. PC Master Software Start Parameters Tuning Window Software Customizing to Motor Speed Control Setting Number of commutations per motor revolutionRange 0,255 Maximal speed range rpm Minimal speed of the drive rpmRange 0,SPEEDRANGEMAXRPM Speedminrpm = 0.07 to 0.5SPEEDMAXRPM User Guide 153 Execute from Evaluation Board Set PC master software control mode and start motor see Remote Operating ModeStart motor see Application Control and PC Master Software PWM Frequency PWM Frequency and Current Sampling Period SettingFor the PWM frequency setting, follow the label PWM frequency setting is provided by PWM Frequency Setting PWM period = Periodpwmus = SETPERPWM*2 EQCurrent Sampling Period Current Sampling Instant Conclusion Software Parameters Setting and TuningCANCHANGEPERCURSAMPn in const.h file PERCST1US = Periodpwmus * Setpercs ∝s User Guide 159 Designer Reference Manual DRM028 Rev 160 User Guide Appendix A. References AN1627, Motorola Motor using MC68HC705MC4 document order number SG40N Appendix B. Glossary Glossary Serial communications interface module SCI a module that Designer Reference Manual DRM028 Rev 166 Glossary Freescale Semiconductor, Inc HOW to Reach US USA/EUROPE/LOCATIONS not Listed