Application Brief
Field Oriented Control Using
XC886/888 MCU
Field Oriented Control of a Permanent Magnet Motor Using a Cost Effective 8-bit µC
Field Oriented Control is increasingly being used in consumer and industrial motor
control owing to the Higher Efficiency, Better Dynamic response and Lower Torque
Ripple. Typically a 16 or 32-bit MCU or DSP is required to handle the complex
trigonometric equations. Infineon’s XC886/888 offers the full benefits of FOC at a
fraction of the cost compared to DSP/DSC solution.
Compared to today‘s solution on the market, where FOC execution engages the
whole central processing unit‘s (CPU) load, FOC execution on Infineon’s XC886 and
XC888 microcontrollers only requires 58 percent of the CPU’s performance providing
ample headroom for other applications. Unlike most hard-coded competitive
FOC implementations, Infineon provides the additional benefit of software reprogrammability adding flexibility and potential for differentiation to the application.
Field Oriented Control implemented on an 8-bit MCU is the perfect answer to energy
related regulations and pricing pressure for appliance manufacturers.
XC886/888 Block Diagram
Vector Computer
8051 Microcontroller
Two Cycle Machine
Cordic 16 bit
MDU 16 bit
MultiCAN
OCDS
Main Clock
Vector Rotator
Multiply
Node A
RAM 64 x 8
9.6 MHz OSC
Sinh & Cosh
Divide
Node B
ROM 1 K x 8
PLL
UART
XC800 Core
UART
8051 Compatible
UART1
Two Clocks per Machine Cycle
4 Result
Registers
10-bit ADC
8 Channel
Multiplexer
Timer
SSC
SSC
A/D Converter
T0
T1
T2
T21
CapCom6E 16 bit
WDT
Key Features of XC886/888 which
enables Field Oriented Control
■ High performance 16-bit vector computer
(CORDIC + MDU)
– Fully programmable co-processor
– Key functions
• Vector rotation and transformations
like Park transform
• Normalizing and scaling
– Interrupt based operation with
minimum CPU load
■ PWM unit for advanced motor control
(CapCom6E)
– 16-bit resolution for high precision
space vector PWM generation
– Dead time control for minimum
hardware effort (direct control of
MOSFET/IGBT)
– CTRAP provides hardware overload
protection
■ A fast 10-bit A/D Converter
(conversion time of less than 1.5 µs)
– Enables single shunt current
measurement
– Reduced torque ripple due to
minimized blind angle
– Hardware synchronization to PWM unit
reduce CPU load
– Two result registers to maximize
sampling performance
Space Vector PWM
Flash or ROM
XRAM
RAM
Boot ROM
24 K/32 K x 8
1.5 K x 8
256 x 8
12 K x 8
Dead Time Hall Sensor
Input
Control
Trap
Control
Applications
Home appliances
■ Industrial and automotive motor control
■
Ports
P0
P1
P2
www.infineon.com/microcontrollers
Microcontrollers
P3
P4
P5
For more information please visit
www.infineon.com/XC886
Application Brief
Implementation of Field Oriented Control
Traditional Implementation of Field Oriented Control
+
0
-
Target
Velocity +
Velocity
PI-Controller
-
ω
+
-
Id
PI-Controller
Vd
Iq
PI-Controller
Vq
Vα
ejΦ
Vector
Rotation
Φ
Velocity
Calculation
Vβ
U
V
Space Vector
Modulator
■
Software based calculations
demands a high performance MCU
(16/32-bit MCU or DSP)
– High system cost
– Complex software development
■
In-built vector computer boosts
computing performance
– 8-bit MCU able to implement
FOC with only 58% CPU load
8051 based solution offers
significant advantages
– Lower system cost
– Ease-of-use
PWM Unit
with
Integrated
Deadtime
Control
W
Flux
Estimator
Trigger
Id
e-jΦ
Vector
Rotation
Iq
Iα
Iβ
Software
Current
Calculation
&
3Φ to 2Φ
Fast ADC
w/Hardware
Trigger
IZ
Shunt
Hardware
XC886/888 Based Implementation of Field Oriented Control
+
0
-
Target
Velocity +
Velocity
PI-Controller
-
+
-
Id
PI-Controller
Vd
Iq
PI-Controller
Vq
Vα
ejΦ
Vector
Rotation
Vβ
U
Space Vector
Modulator
PWM Unit
with
Integrated
Deadtime
Control
V
W
■
ω
Φ
Velocity
Calculation
Flux
Estimator
Trigger
Id
Iq
e-jΦ
Vector
Rotation
Iα
Iβ
Vector Computer
Software
Current
Calculation
&
3Φ to 2Φ
Fast ADC
w/Hardware
Trigger
IZ
Shunt
Hardware
Infineon’s XC800 8-bit Family Offers the Scalability Required for a Wide Range of Motor Control Applications
MCU Performance
XC888
■
■
XC866-2/4FR
■
XC866-1FR
Scalable MCU solutions
XC866 series offers a cost-effective
solution for Block Commutation
Motor Drive
XC886/888 series offers the
performance boost required for
Sensor-less Field Oriented Control
Motor Control Method
Block Commutation
with Hall Sensor
Block Commutation
Sensor-less
Published by Infineon Technologies AG
Field Oriented Control
Sensor-less
Ordering No. B158-H8983-X-X-7600
Printed in Germany
PS 0207.5 nb