Sensorless PMSM Field Oriented Control Solution
Based on TI Cortex-M3
AEDS Team
Technical Service
Arrow Steven Wang
AgendaAgenda
�� Permanent Magnet Synchronous MotorPermanent Magnet Synchronous Motor
�� Field Oriented Control RealizationField Oriented Control Realization
�� Sensorless Control TechniqueSensorless Control Technique
�� Stellaris Microcontrollers Stellaris Microcontrollers
�� PMSM Solution Demo ShowPMSM Solution Demo Show
�� Technical Support for Motor ControlTechnical Support for Motor Control
�� Permanent Magnet Synchronous MotorPermanent Magnet Synchronous Motor
TIDave’sControlCenter
Permanent Magnet Synchronous Motor
Stator
Rotor
Permanent Magnet Rotor
SPMSM IPMSM
Sinusoidal Winding Distribution
Stator winding density is sinusoidally distributed,thus creating a sinusoidally distributed flux density
Phase A shown
Three Phases Winding DistributionPhase A Phase B Phase C
A
B
C
Blue arrows show axes of magnetism for each coil
How to Create a Rotating Magnet Field?
� Stator coils spatially separated from each other by 120 degrees
� Drive with three-phase sinusoidal currents separated in phase by 120 degrees
� Three pulsating magnetic fields are generated on their respective magnetic axes
� A smoothly rotating magnetic vector is generated by synthesizing these vectors
Orientation of Field for Max Torque
(Reluctance torque assumed to be zero)
Axis of rotor flux is fixed with respect to the rotor, i.e., it is “synchronous”.S
N
The green vector represents the stator flux vector which results from the sinusoidal currents being applied to the stator coils.
PMSM Motors Summary
Advantages
� High power output per frame size� High torque inertia ratio� High efficiency due to small rotor losses� Very low torque ripple� Structure inherently allows heat to be easily removed� Zero speed sensorless operation possible with IPM motors� Extended speed range operation for IPM using weak field
�� Field Oriented Control RealizationField Oriented Control Realization
TIDave’sControlCenter
How to Control Torque on a DC motor?
+310V
0.015
PWM1
PWM1PWM2
PWM2PWM1
PWM2
PIController
+
-
ADC1
D esired CurrentD esired CurrentD esired CurrentD esired Current
M easured CurrentM easured CurrentM easured CurrentM easured Current
E rror S ignalE rror S ignalE rror S ignalE rror S ignal
Commutator keeps rotor and stator fields properly aligned!
Brush DC Motor
Texas Instruments
Dave’sMotor Control
Center
M easure current already flow ing in the m otor.M easure current already flow ing in the m otor.M easure current already flow ing in the m otor.M easure current already flow ing in the m otor.1.1.1.1.
1
Com pare the m easured current w ith the desired current, and generCom pare the m easured current w ith the desired current, and generCom pare the m easured current w ith the desired current, and generCom pare the m easured current w ith the desired current, and generate an error signal.ate an error signal.ate an error signal.ate an error signal.2.2.2.2.
2
A m plify the error signal to generate a correction voltage.A m plify the error signal to generate a correction voltage.A m plify the error signal to generate a correction voltage.A m plify the error signal to generate a correction voltage.3.3.3.3.
3
M odulate the correction voltage onto the m otor term inals.M odulate the correction voltage onto the m otor term inals.M odulate the correction voltage onto the m otor term inals.M odulate the correction voltage onto the m otor term inals.4.4.4.4.
4
A
B
C
Controllerwith A/D
iiii a
iiii b
iiii c
Step1. Measure current already flowing in the motor
Texas Instruments
Dave’sMotor Control
Center
0=++ cba iii
bac iii −−=
Clarke Transform
aii =α
cb iii3
1
3
1 −=β
αi
βi
A
B
C
si
iiii b
iiii c
iiii a
α
β
Park Transform
αi
βi
A
B
C
si
ddq
ddd
iii
iii
θθθθ
βα
βα
cossin
sincos
+−=
+=
θd
d axis
q axis
rotor flux axis
iiii q
iiii d
iiii d
∫ IIII
PPPP+
+
+-
error(t)
∫ IIII
PPPP+
+
+-
error(t)
(commanded)
iiii d(measured)
iiii q
iiii q (commanded)
(measured)
vvvvd
vvvvq
Step2and3. D Axis and Q Axis PI Current Controller
The PI regulator is a good choice for current regulation
Modulated voltages Inv-Park
dqdd
dqdd
vvv
vvv
θθθθ
β
α
cossin
sincos
+=
−=
Voltage vector
αv
βv
d axis
q axis
θd
A
B
C
vvvv d
vvvv q
rotor flux axisrotor flux axisrotor flux axisrotor flux axis
α
Step4. Space Vector Modulation
SWITCHING PERIOD
Vn+1NullVn
T
T1T1 T2T2 T0T0T1 = TT1 = T••mm••SIN(60 SIN(60 -- αα))T2 = TT2 = T••mm••SIN(SIN(αα))T0 = T T0 = T -- T1 T1 -- T2T2
m = desired modulation index
α = desired angle between Vref and Vn
Sector 5
Sector 6Sector 4
Sector 3
Sector 2
V1 = 100V1 = 100
V2 = 110V2 = 110
V4 = 011V4 = 011
V3 = 010V3 = 010
V5 = 001V5 = 001 V6 = 101V6 = 101
ααααT1T1••V1V1
T2
T2••V
2V
2Vref
+
-
Commanded
Rotor
Speed
P
I ∫∫∫∫
+
+
Rotor Speed
Vb
Vc
Va
Control Diagram of a PMSM Variable Speed Control System Utilizing Field Oriented Control.
Commanded iiiid d d d
= 0
+
-
P
I ∫∫∫∫
+
+
+
-
P
I ∫∫∫∫
+
+
Commanded iiiiqqqq
ReverseClark-ParkTransform
ForwardClark-ParkTransform
iiiidddd
iiiiqqqq
Phase C
Current
Calculation
iiiiaaaa
iiiibbbb
iiiicccc
d/dt
θd
θd
Vd
Vq
(torque)TI
Dave’sControlCenter
PMSM
The Whole Scheme for the FOC
�� Sensorless Control TechniqueSensorless Control Technique
TIDave’sControlCenter
PMSM Sensorless Algorithms--- Based BEMF
Ψ+=ΨΨ+=Ψ
Ψ+=
Ψ+=
rMsss
rMsss
ssss
sss
iL
iL
dt
diRU
dt
dRiU
θθ
ββ
αα
βββ
ααα
sin
cos
=
+Ψ−−=
+Ψ+−=
rr
s
s
rr
s
Ms
s
s
s
srr
s
Ms
s
s
pdt
d
L
Utpp
Li
L
R
dt
di
L
Utpp
Li
L
R
dt
di
ωθ
ωω
ωω
ββ
β
αα
α
)cos(
)sin(
=
+−−=
+−−=
rr
s
s
s
s
s
s
s
s
s
s
s
s
pdt
d
L
U
L
ei
L
R
dt
di
L
U
L
ei
L
R
dt
di
ωθ
βββ
β
ααα
α
PMSM 在两相静止坐标轴在两相静止坐标轴在两相静止坐标轴在两相静止坐标轴((((Alpha, Beta))))下数学模型下数学模型下数学模型下数学模型
Ψ=Ψ−=
)cos(
)sin(
tppe
tppe
rrMs
rrMs
ωωωω
β
α
PMSM Sensorless Algorithms
PMSM Model
Based sliding mode
current observer
v
+
-
+K
-K
Slide mode gain
i
i^
e^
Omega^el
e^ --- estimated bemf voltage
Omega^el --- estimated motor speed
theta^ --- estimated position angle
z
Low pass filterFlux angle
calculator
theta^+
+
Flux angle
correction
theta
e^
z
�� Stellaris MicrocontrollersStellaris Microcontrollers
TIDave’sControlCenter
Stellaris Microcontrollers - Made for Motion
High-performance, deterministic, real-time computer
• Fast memories
• Prioritized, vector interrupts
Sophisticated motion-control system
• High-speed PWMs
• Deadband H/W for shoot-through protection
• Fault input
• Digital encoder/resolverinputs
Analog input handling
• High-speed multi-channel ADC for monitoring
• Comparators for zero-crossing detection
• Synchronized with motion system for accurate measurements
Extensive comm and real-time network options
Full system integration for compact size and cost-effectiveness
Stellaris Complete, Open-Tool Motor Reference Design Kits
Example applications:
• White goods
• Residential and light commercial HVAC
• 3-ph Industrial Motor Drives
AC Induction Motor Controller Design
RDK-S
TEPP
ER
$199
Example applications:
• 2 and 3 axis CNC equipment
• Sorting and grading equipment
• Specialized printers and scanners
Example applications:
• Small appliances
• Electric wheelchairs and mobility devices
• Pumping and ventilation systems
Stepper Motor Controller Design
Brushless DC Motor Controller with CAN/Ethernet
Example applications:
• Small appliances
• Electric wheelchairs and mobility devices
• Pumping and ventilation systems
Brush DC Motor Controller with CAN
RDK-A
CIM
$379
RDK-B
LDC
$219
Official FIRST KoP Speed
Controller – FRC 2009
RDK-B
DC
$219
�� PMSM Solution Demo ShowPMSM Solution Demo Show
TIDave’sControlCenter
PMSM Solution Demo Show PMSM Solution Demo Show
Major FeaturesMajor Features
1 High performance FOC algorithms
2 Sensorless Control Technique
3 Constant Speed Control
4 Constant Torque Control
5 High Efficiency
6
7 Stepless Speed Adjusting
8 Remote Control: RS232/485
9 OC,OV,UV Protection etc
Two Shunt Current Sampling
Debug PC Software
PMSM Parameters Used for TestPMSM Parameters Used for Test
1. Rated Input Power: 200W
2. Rated Speed : 1120RPM
3. Rated Torque: 0.6N.m
4. Max Torque : 1.2N.m
5. Max Efficiency: 75%
Fan Motor Test EquipmentFan Motor Test Equipment
�测功机测功机测功机测功机
�测功机控制器测功机控制器测功机控制器测功机控制器
�测功机动态控制器测功机动态控制器测功机动态控制器测功机动态控制器
�电参数测量仪电参数测量仪电参数测量仪电参数测量仪
Test Result Analysis(1)Test Result Analysis(1)
恒速度恒速度恒速度恒速度
恒转矩恒转矩恒转矩恒转矩效率效率效率效率
功率功率功率功率
Test Result Analysis(2)Test Result Analysis(2)
Test Result Analysis(3)Test Result Analysis(3)
U 相电流相电流相电流相电流
Hall 位置位置位置位置
估算位置估算位置估算位置估算位置
Technical SupportTechnical Support
� Technical Training for Motor Control
� HW Reference Design
� SW Reference Design packed
� Field Debug Support and Service
� Help develop in our lab
Q & A