Software Design
System Description, Rev. 1
Freescale Semiconductor
2-5
Preliminary
2.3.1 Data Flow
The control algorithm of a closed-loop BLDC drive is described in
Figure 2-3
. The individual processes are
described in the following sections.
Capture Interrupt
SensorState
Hall
Sensors
Calculate Actual
Speed
MeasuredVoltageFraction
Speed
Setting
via
Button
Calculate Desired
Speed
DesiredVoltageFraction
PI Speed Controller
PI Speed Controller
DCBus
Current
ADC Conversion
Interrupt
Calculate Moving
Average
ADCAvg
PI Torque
Controller
Mask and Swap
Calculation
DCBus
Voltage
ADC Conversion
Interrupt
Calculate Moving
Average
DCBusAvg
PWM
Generation
Yes
DutyCycle
Calculate Duty
Cycle
Overvoltage
Fault?
Shutdown PWM
Figure 2-3. Main Data Flow
The main data flow can be divided into five parts:
•
Speed control
•
Torque control
•
Velocity calculation
•
Rotor commutation
•
DCBus voltage measurement
Summary of Contents for 56F8000
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Page 10: ...3 Phase BLDC Motor Control Rev 1 viii Freescale Semiconductor Preliminary...
Page 12: ...Introduction 3 Phase BLDC Motor Control Rev 1 1 2 Freescale Semiconductor Preliminary...
Page 20: ...System Description 3 Phase BLDC Motor Control Rev 1 2 8 Freescale Semiconductor Preliminary...
Page 26: ...Index Rev 1 Freescale Semiconductor Index 2 Preliminary...
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