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 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

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