Embedded control of an Adaptive Magnetic Flux Array challenges of distributed software in Power electronics system
Sylvain Laversanne - August 14 2014 Summary
1. AMFA technology explained
2. Architecture and challenges
3. Software development
4. Conclusions
About AXIFLUX
Axiflux® was incorporated in Melbourne, 2011 to research, design, manufacture and distribute a revolutionary range of electric motors and generators.
The founding group are highly entrepreneurial focused on pushing the innovation envelope to its limits.
Initial areas of focus encompass: • High-efficiency, high power density electric vehicle motors • Commercial pumps and ventilation fans • Conveyor belt motors • Direct-drive wind turbines
AMFA technology explained Concept of the Adaptive Magnetic Flux Array : - Permanent Magnet Motor with an Axial Flux configuration: - Compact & Efficient - High Torque low speed
- Independently controlled coils: - Low ripple, low cogging torque - High Reliability - Freedom of design
- Applications: - Direct drive - High Torque electronically speed/torque controlled motors - In built redundancy
AMFA technology explained Electronically controlled integrated motor : lab version, AMFA1
Rotor
Power electronics
Stator AMFA technology explained Electronically controlled integrated motor : lab version, AMFA2
Stator
Rotor
Power electronics AMFA technology explained Concept of an axial flux motor
Coils Magnets
Radial type AMFA technology explained High torque and high efficiency motor
AMFA technology explained Independently driven coil motor pos … neg 1 2 3 n-1 n
pos
Each coil is driven by its own power electronics module
neg Architecture and challenges
Sensors and peripherals
Piccolo DSP (1 of n slaves)
6 I2C low speed peripherals 4 2
0
-2
-4
-6 0 1 2 3 4 5 6 7 8 9 -3 x 10
Analog signals (I,V,etc.)
High speed CANbus and Isolated Serial bus Delfino DSP Master/Interface DSP
Complex network & architecture ( analog, CANbus, I2C, serial, SPI, etc.) Architecture and challenges
Fast Control loop
Piccolo DSP 6
4
2 0 -2
-4
-6 0 1 2 3 4 5 6 7 8 9 -3 x 10
Analog signals (I,V,etc.)
Each Module is an arbitrary high power module: - Current waveform up to 1200Hz and more - Phase is critically locked - Feedback regulation in a single phase non stationary frame - Software fault detection is critical - Sampling Time is <35µs
Real Time, synchronised, Multitasking software Software development
Classic approach, requiring :
- Model in the Loop simulation
- Software in the loop simulation
- Rapid control prototyping
- Model based design
- Data logging and analysis
Software development Software architecture
INPUTS DATA PROCESSING & CALCULATION & OUPUT SAFETY CONTROL ADCs ePWM FAULT State Handling calculation
GPIOs CANbus Observers Conditioning & Error check Serial Control CANbus
I2C Modulation & conditioning
DATA Bus Delayed loop Software development Simulation architecture
DATA PROCESSING & CALCULATION & SAFETY CONTROL
FAULT State Handling calculation
Observers Conditioning & Error check Control
Modulation & conditioning
DATA Bus Delayed loop
SIMULATION Software development Tools used:
MATLAB R2014a
Simulink
Fixed Point Designer
Embedded Coder (C2000 DSP family)
Vehicle Network Toolbox
TI Code Composer Studio v5.5 Software development Example of time saver: Full DSP configuration with GUI
Software development Example of time saver: Direction implementation of standard CANbus databases
Software development Example of time saver: GUI aided fixed-point design Access to optimised fixed-point mathematical functions
Software development Example of time saver: Multitasking OS and easy use with minimum overhead
3 µs overhead for context switching between main interrupt and task start
Conclusions
- Fast tasking 25khz and more multitasking software is possible without compromising with easy integration of network interfaces & peripherals
- Advantages of a model-based software (understandable, sharable, etc)
- MATLAB tools are time saving: for the same software design time has been divided by 5
- Rapid prototyping with embedded coder doesn’t require a specific hardware
- Versatile tool allowing rapid prototyping of any ECUs
- Versioning tools already integrated in the package
- Generated code is compliant with classic standard