AN1931D Freescale Semiconductor / Motorola, AN1931D Datasheet - Page 49

• Manufacturer Part Number: AN1931D
• Description: 3-Phase PM Synchronous Motor Vector Control
• Manufacturer: Freescale Semiconductor / Motorola

MOTOROLA
7.1.3 Speed Scaling
7.1.4 Position Scaling
7.1.5 Temperature Scaling
7.2 PI Controller Tuning
7.3 Subprocesses Relation and State Transitions
Speed quantities are scaled to the defined speed range maximum, which should be set lower than all
speed variables in the application, so it was set higher than the maximum mechanical speed of the
drive. The relationship between real and fractional representation of speed quantities is:
where:
OMEGA_RANGE_MAX Defined speed range maximum used for scaling in physical units[rpm]
In the application, the OMEGA_RANGE_MAX value is defined as:
Other speed variables are scaled in the same way (omega_reqPCM_mech, omega_desired_mech,
omega_required_mech, omega_reqMAX_mech, omega_reqMIN_mech, omega_actual_mech).
The relation between speed scaling and speed measurement with encoder is described in
Section
constant k in equations
Position Scaling is described in
As shown in
The application consists of four PI controllers. Two controllers are used for the I
for speed control and the other for field-weakening. The controller’s constants are given by simulation
in Mathlab and were experimentally specified. A detailed description of controller tuning is beyond the
scope of this application note.
As shown in
functionality. The application code is designed to be able to extract individual processes, such as
Analog Sensing, and use them for customer applications. The C language functions dedicated for each
process are located in one place in the software, so they can be easily used for other applications. The
function naming usually starts with the name of the process, for example, AnalogSensingInitProceed().
As
example, Application Control: Begin Initialization is a condition for transient of the Analog Sensing
process: Init Done to Begin Init state. In the code, the interface between processes is provided via
“trigger” functions. The naming convention is for these functions is: <ProcessName><State>Trig().
Frac
Real
Section 6.3
OMEGA_RANGE_MAX = 6000rpm
4.3.1.2. In the final software, the constant OMEGA_SCALE is identical with the scaling
Section
Section 6.2
shows, the processes’ or subprocesses’, state transients have some mutual relations. For
4.3.4, the temperature variable does not have a linear dependency.
(EQ 4-1.)
Freescale Semiconductor, Inc.
3-Phase PM Synchronous Motor Vector Control
Frac
For More Information On This Product,
Fractional representation of speed quantities
Real speed quantities in physical units
and
=
Section 4.3.1.1
Section
and
------------------------------------------------------------- -
OMEGA_RANGE_MAX
Go to: www.freescale.com
(EQ
6.3, the software is split into subprocesses according to
4-3.), and OMEGA_RANGE_MAX is
Real
Implementation Notes
d
and I
Max
q
.
currents, one
[rpm]
[-]
(EQ 7-9.)
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