AN1913 Motorola / Freescale Semiconductor, AN1913 Datasheet - Page 41

• Manufacturer Part Number: AN1913
• Description: AN1913 3-phase BLDC Motor Control with Sensorless Back-EMF ADC Zero Crossing Detection using DSP 56F80x
• Manufacturer: Motorola / Freescale Semiconductor

7.3.4 State Diagram - Process Commutation Control
Reset
A State Diagram of the process Commutation Control is illustrated in
Control process takes care of the sensorless BLDC motor commutation. The requirement to run the
BLDC motor is determined by the upper software level Application State Machine. When the
Application State Machine is in the BLDC Stopped state, Commutation Control status is stopped. If it
is in the BLDC Stopped state, the Commutation Control goes through the states described in Section
Section
Drive Fault
•
•
•
•
Alignment state
— Motor is powered with current through two phases - no commutations provided
Starting (Back-EMF Acquisition) state
— Motor starts with first two commutations, then it is running (as in the Running state) using
Running state
— Motor is running with Run parameters for commutation calculation RunComputInit
Stopped state
— Motor is stopped with no power going to motor phases
5. The following states are possible:
Figure 7-7. State Diagram - Process Application State Machine
BLDC Stop
Start parameters for commutation calculation StartComputInit (so the commutation
advance angle and the Per_Toff time are different)
Required Speed
Up Button
(Switch = Stop) || (abs (Required Speed) <= Minimal Speed)
Increment
(Switch = Run) & (abs (Required Speed) > Minimal Speed)
BLDC control with BEMF Zero Crossing using ADC
Emergency Stop
Drive Fault
Required Speed
Down Button
Decrement
with Required Speed
BLDC Run
Required Speed setting
Figure
Required Speed
PC Master
7-8. The Commutation
Set
Drive Fault
Software Design
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