release 3-Phase ACIM Vector Control, Rev. 0
Freescale Semiconductor
3
3-Phase AC Induction Motor Vector Control on
Processor Expert
This application exercises vector control of the 3-phase AC Induction Motor (ACIM) using Processor
Expert (PE), a 56F8346, 56F8357, or 56F8367 EVM board, and 3-phase AC / BLDC High-Voltage (HV)
power stage.
Applications developed for this demonstration board were not designed for the 56F8100 devices. The
56F8300 demonstration board does, however, fully support 56F8100 software development.
Note: The PC master software referenced in this document is also known as Free Master software.
1.
Specifications
This application performs principal vector control of the 3-phase AC induction motor using a 56F8300
processor. The concept of the application is a speed closed-loop AC drive using a vector control technique.
The control technique obtains d and q current components and rotor flux vector from regularly sampled
3-phase stator currents. The d and q current components and rotor flux are controlled separately. The q
component corresponds to torque and the d component corresponds to flux. An incremental encoder is
used to derive the actual rotor speed.
The Actual Speed, derived from a quadrature decoder, monitors the actual behavior of the system, and is
compared with the reference signal (Required Speed).
Protection is provided against overcurrent, overvoltage, undervoltage, and overheating drive faults.
System Outline
The system is designed to drive a
3-phase ACIM
. The application has the following specifications:
Vector control technique used for AC induction motor control Speed control loop Targeted for
a 56F8346, 56F8357, or 56F8367 EVM Runs on a 3-phase ACIM control development platform at variable line voltage 115V AC and 230V
AC (range -15% to +10%) Motor mode Generator mode DCBus brake Minimum speed 50rpm Maximum speed 2500rpm at input power line 230V AC Maximum speed 1100rpm at input power line 115V AC Fault protection 3-Phase ACIM Vector Control, Rev. 0
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Freescale Semiconductor Interfaces:
Manual interface
RUN / STOP switch
UP / DOWN push buttons control
LED indication
PC master software remote control interface
START MOTOR / STOP MOTOR push buttons
Speed set-up PC master software remote monitor
Software monitor interface
Required speed
Actual motor speed
PC master software mode
START MOTOR / STOP MOTOR controls
Drive fault status
DCBus voltage level
Drive status
Mains detection
Software speed scope
Observes actual and desired speed
Software recorder for:
Phase currents
D, q currents
Application Description
The vector control algorithm is calculated on Freescales 56F8346EVM, 56F8357EVM, or 56F8367EVM.
The algorithm generates 3-phase PWM signals for the ACIM inverter according to the user-required
inputs, measured and calculated signals.
The concept of the ACIM drive incorporates the following hardware components: ACIM motor-brake set 3-phase AC / BLDC high-voltage power stage 56F8346EVM, 56F8357EVM, or 56F8367EVM Legacy Motor Daughter Card (LMDC) In-line optoisolation box, ECOPTINL, which is connected between the host computer and the
56F83xxEVM 3-Phase ACIM Vector Control, Rev. 0
Freescale Semiconductor
5
Note: The AC induction motor-brake set incorporates a 3-phase AC induction motor and attached BLDC
motor brake. The AC induction motor has four poles. The incremental position sensor (encoder) is
coupled on the motor shaft. See
Table 1-1
for detailed motor-brake specifications.
Table 1-1 Motor Brake Specifications
The drive can be controlled in two operating modes: In the Manual operating mode, the required speed is set by UP / DOWN push buttons and the drive is
started and stopped by the RUN / STOP switch on the EVM board In the PC master software operating mode, the Required Speed is set by the PC master software
active bar graph and the drive is started and stopped by the START MOTOR and STOP MOTOR
controls
Measured quantities: DCBus voltage Phase currents (Phase A, Phase B, Phase C) Power module temperature Rotor speed
The faults used for drive protection: Overvoltage (PC master software error message = Overvoltage fault) Undervoltage (PC master software error message = Undervoltage fault) Overcurrent (PC master software error message = Overcurrent fault) Overheating (PC master software error message = Overheating fault)
Set Manufactured
EM Brno, Czech Republic
Motor
Motor Type
AM40V
3-Phase AC Induction Motor
Pole Number
4
Nominal Speed
1300rpm
Nominal Voltage
3 x 200V
Nominal Current
0.88A
Brake
Brake Type
SG40N
3-Phase BLDC Motor
Pole Number
6
Nominal Speed
1500rpm
Nominal Voltage
3 x 27V
Nominal Current
2.6A
Position Sensor (Encoder)
Type
Baumer Electric
BHK 16.05A 1024-12.5
Pulses per revolution
1024 3-Phase ACIM Vector Control, Rev. 0
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Freescale Semiconductor
The following software tools are needed for to compile, debug, and load to the EVM, and to use remote
control and monitoring, and the RUN / STOP Switch and UP / DOWN Buttons: Metrowerks CodeWarrior v. 6.1.2 PC master software Processor Expert v. 2.94
Control Process
After reset, the drive enters the INIT state in manual operation mode.When the RUN / STOP switch is
detected in the STOP position and there are no faults pending, the STOP application state is entered.
Otherwise, the drive waits in the INIT state, or if faults are detected, the drive goes to the FAULT state. In
the INIT and STOP states, the operation mode can be changed from
PC master
software. In the manual
operational mode, the application is operated by the RUN / STOP switch and UP / DOWN buttons; in the
PC master
remote mode, the application is operated remotely by
PC master software
.
When the Start command is accepted (using the RUN / STOP Switch or
PC master
software command), the
rotor position is aligned to a predefined position to obtain a known rotor position. The rotor alignment is
done at the first start command only. Required speed is then calculated according to UP / DOWN push
buttons or
PC master
software commands (if in
PC master
software remote mode). The required speed goes
through an acceleration/deceleration ramp. The comparison between the actual speed command and the
measured speed generates a speed error. Based on the error, the speed controller generates a stator current,
Is_qReq, which corresponds to torque. A second part of the stator current, Is_dReq, which corresponds to
flux, is given by the Field Weakening Controller. Simultaneously, the stator currents Is_a, Is_b and Is_c
are measured and transformed from instantaneous values to the stationary reference frame , , and
consecutively to the rotary reference frame d, q (Clarke-Park transformation). Based on the errors between
required and actual currents in the rotary reference frame, the current controllers generate output voltages
Us_q and Us_d (in the rotary reference frame d, q). The voltages Us_q and Us_d are transformed back to
the stationary reference frame , and, after DCBus ripple elimination, are recalculated to the 3-phase
voltage system, which is applied on the motor.
Drive Protection
The DCBus voltage, DCBus current and power stage temperature are measured during the control process.
They protect the drive from overvoltage, undervoltage, overcurrent and overheating. Undervoltage and
overheating protection is performed by software, while the overcurrent and over voltage fault signal
utilizes a fault input of the hybrid controller. Line voltage is measured during application initialization and
the application automatically adjusts itself to run at either 115V AC or 230V AC, depending on the
measured value.
If any of the previously mentioned faults occur, the motor control PWM outputs are disabled to protect the
drive, and the application enters the FAULT state. The FAULT state can be left only when the fault
conditions disappear and the RUN / STOP switch is moved to the STOP position manual mode or by the
PC master
software in the
PC master
software remote mode. 3-Phase ACIM Vector Control, Rev. 0
Freescale Semiconductor
7
The application can run on: External RAM or Flash 3-Phase AC / BLDC High-Voltage Power Stage powered by 115V AC or 230V AC Manual or PC master software operating mode
The voltage level is identified automatically and the appropriate constants are set.
The 3-phase AC Induction Motor Control Application can operate in two modes:
1. Manual Operating Mode
The drive is controlled by the RUN / STOP switch (S3) on the Legacy Motor Daughter Card (LMDC). The
motor speed is set by the UP (S1) and DOWN (S2) push buttons on the LMDC; see
Figure 1-1
. In this
application, the PWMA module output LEDs are used as USER LEDS. If the application runs and motor
spinning is disabled (i.e., the system is ready), the GREEN USER LED (LED2, shown in
Figure 1-2
) will
blink. When motor spinning is enabled, the USER LED is On. Refer to
Table 1-2
for application states;
the actual state of the PWM outputs are indicated by PWMB output LEDs. If overcurrent, overvoltage or
overheating occur, the GREEN USER LED (LED2) starts to flash quickly and the PC master software
signals the type of fault identified. This state can be exited only by an application reset. It is strongly
recommended that you inspect the entire application to locate the source of the fault before starting it
again. Refer to for application states.
Figure 1-1 RUN / STOP Switch and UP / DOWN Buttons on the
Legacy Motor Daughter Card (LMDC)
UP / DOWN
Buttons
RUN / STOP
Switch 3-Phase ACIM Vector Control, Rev. 0
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