AN1914 Freescale Semiconductor / Motorola, AN1914 Datasheet - Page 37

• Manufacturer Part Number: AN1914
• Description: 3-Phase BLDC Motor Control with Sensorless Back EMF Zero Crossing Detection Using DSP56F80x
• Manufacturer: Freescale Semiconductor / Motorola

7.2.1 Process Application State Machine
7.2.2 Process Commutation Control
7.2.3 Process Speed PI Controller
DC-Bus Current
This process controls the application subprocesses by status and command words as can be seen in
Figure 7-3.
Based on the status of the Status_Commutation (set by the Commutation Control process) the
Cmd_Application Rq flags are set to request calculation of the Current PI Controller (Alignment
state) or Speed PI Controller (Running state) and to control the angular speed setting (reflects the
status of the START/STOP Switch and the Run/Stop commands).
This process controls sensorless BLDC motor commutations as explained in
Step_Cmt and Cmt_Drv_RqFlag, are used to set the PWM Generation process. The output
Omega_Actual_Mech is used for the Speed Controller process.
The general principle of the speed PI control loop is illustrated in
(A/D)
I_Dc_Bus
Application
State Machine
Process
DSP56F80x MC PWM Module in Motor Control Applications
Freescale Semiconductor, Inc.
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DriveFaultStatus
Temperature
Temperature
Process
Fault Control
Figure 7-4. Data Flow - part2
(A/D)
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PVAL0,PVAL1
DC-Bus Voltage
U_Dc_Bus
(A/D)
PVAL2,PVAL3
PWM Generation
Figure 7-5.
Process
(OverVoltage/OverCurrent)
PWM Faults
Section
PVAL4,PVAL5
5. Its outputs,
SW Design
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