cost-effective sensor and sensorless brushless dc … motor control – market trends market trend...

TM

Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2009.

Cost-Effective Sensor and Sensorless Brushless DC (BLDC) Motor Control ApplicationsF0225

August, 2009

T.C. LunSystem & Application Engineer

TM

2Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2009.

Agenda

►Industrial motor control market• Target applications• Market trends• Freescale alignment with trends• Freescale motor control processors

►Brushless DC (BLDC) motor control solutions• BLDC motor characteristic• Sensorless Solution Examples• Tools, Resources and Summary

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Industrial Motor Control Market

TMFreescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2009. 4

Industrial Motor Control Target Applications

►Pumps and fans – pool pumps, factory systems

►HVAC – heating fans, air-conditioners

► Industrial drives – manufacturing assembly, robotics, wind turbines, printing presses

►Appliances – washers, dryers, power tools

►Medical – scanners, pumps, diagnostic and therapy equipment


Industrial Motor Control – Market Trends

Market Trend Customer RequirementsReduce power consumption

►Intelligent motor control improves efficiency by 30% or more►Implement variable speed motor control with inverter-based drive systems►Smarter systems to sense environment and react in real time

Reduce system and development cost

►More on-chip peripherals to reduce component count►Libraries and reference designs for common functions►Expert customer support

Reuse software, hardware and tools across platforms

►Support multiple motor types with one unified platform►Ease software migration across wide performance range►Tools to develop increasingly complex algorithms

Cost-effective safety, reliability and security

►IEC regulatory approval requires single-bit failure detection►On-chip protection against IP cloning and network data hacking►Easier product certification to meet safety standards


Industrial Motor Control – Freescale Alignment with Trends

Market Trend Freescale Alignment with Customer RequirementsReduce power consumption

►Vector and sensorless control technology designed into every motor control processor

Reduce system and development cost

►8- and 16-bit MCUs start at <$0.70►16-bit DSCs for ACIM and PMSM solutions►32-bit Power Architecture MCUs for standard/premium drives

Reuse software, hardware, and tools across platforms

►Rich tools, training, reference designs and libraries►Devices are ruggedized with long life and reliability►Industrial products ship 10+ years, with high quality and expertcustomer support

Cost-effective safety, reliability and security

►Secure SRAM, on-chip data fusing to protect against IP cloning►Hardware encryption to protect against network data hacking ►Watchdog and ECC protection against soft errors►Certified IEC software modules


Typical Motor Control MCU Peripheral Functions

►Timer:• PWM signals < 20Khz• Dead time insertion• Commutation (mask-out)• ADC triggering• Fault control

►ADC• Measure current

►Delay block• Set ADC measurement at

specific times►Position decoder

• Quadrature decoder inputs if not sensorless

6 ch PWMtimer

12 bit ADC

Fault inputs

Prog delay

Positiondecoder


Choosing your MCU therefore depends upon …

►The same application may perform differently if implemented on different MCUs

►Peripheral features can significantly impact target application performance, not just CPU

► Application features should be considered• Type of motor• Type of load• Operational mode• Minimal speed• Maximal speed

• Current control• Speed control and/or position control• Number of PID controllers• Fault control• System Cost!


Brushless DC Motor

Recommended devices► Hall sensors (commutated)

function:• 8-bit: MC9S08AW and

MC9S08AC

► Sensorless function:• DSC: MC56F8006

MC56F8013 MC56F8037 MC56F8025 (MC56F83xx for servo)

• ColdFire 32-bit: MCF5234 with 16-channel enhanced time processing unit (eTPU)

• Dual H-bridge (12V): MC33932

• FET driver: MC33937

Applications► Fans and pumps► HVAC, compressors, blowers► Computer disk drives and peripherals► Robotics, traction control, servo systems► Office equipment, sewing machines, treadmills


Freescale Motor Control Processors

Low-end Compact6 – 30 MMIPS< 0.5 W< $1

Mid-range Motor Control30 – 80 MMIPS< 0.5 – 1 W$1 - $3

High-end Motor Control60 – 100 MMIPS< 0.5 – 1 W> $3

MC9S08MP16

MPC5604P

DSC56F83xx

DSC56F8037

DSC56F8013

MC9RS08KA MC9S08QD/QE

MC9S08SH MC9S08AC

PoE MC34670H-bridges

MC33880, 87, MC33926, 32

CAN PHY MCZ33897

Power SupplyMC34727, 26

Linear RegulatorMC33742, MC33910, 11,12

Signal ConditioningMC33972, 75

Analog

2 0 0 8 2 0 0 9

DSC 16-bit S08 8-bit

Power® e200

DSC56F8006/2

DSC56F82xx

AnalogLED backlightMC34844, 45

Pre-driver MC33937


56800E Core/32MIPS JTAG/EOnCE™

ProgrammableDelay Block (PDB)SPIVoltage Regulators

6 Output PWMI2CInterrupt Controller

2x 12-bit ADCsHigh Speed SCIFlash/RAM

1x 16-bit PeriodicInterval TimerCOPTwo 2X-16X

Wideband PGAs

2x 16-bit TimersPower SuperVisor3 AnalogComparators

Memory Options

16 KBFlash

12 KBFlash

2 KBSRAM

2 KBSRAM

System Integration Module(SIM)

System Clock Control（PLL, SIM, Osc)

MC56F8006/2Features

• 16k Flash• 2k bytes of SRAM• Up to 32 MHz bus• Single-cycle 16 × 16-bit parallel multiplier-accumulator (MAC) • On-chip oscillator—requires no external components• Four 36-bit accumulators, including extension bits

►Serial Communication• IIC (synchronous), SPI (synchronous) and SCI (asynchronous)

►Timers • Six output PWM with programmable fault capability• Two 16-bit timers; one 16-bit periodic interval timer;

programmable delay timer

►Analog Modules• Two 12-bit ADCs• Two 2x-16x PGAs (Programmable Gain Amplifier)• Three analog comparators

• Ultra low power operation (9 different power modes)

►Available Packages: 28W SOIC, 32 LQFP, 48 LQFP


MC9S08AC60Features

►Memory• 16–64 k Flash, capable of EEPROM emulation• 1k–2k bytes of RAM

►Internal Clock Generator (ICG)• Up to 20 MHz bus• FLL with eight software selectable multipliers• On-chip oscillator—requires no external components• Bus clock divider with eight software selectable settings• Separate self-clocked source for real time interrupt • 0.5 percent typical. 2-percent accuracy over full operating range

►Serial Communication• IIC (synchronous), SPI (synchronous) and 2 SCI (asynchronous)

►Timers • 6-channel timer/PWM Module (TPM)• 2-channel timer/PWM Module (TPM)

►Analog Modules• 16-ch., 10-bit analog-to-digital converter• Enhanced LVD

►Development Tools• On-chip ICE and BDM

►Available Packages: 64 QFP, 64 LQFP, 48 QFN, 44 LQFP

60k/32k/16k

Flash

2K/1KRAM

IIC

2 SCI

SPI

KBI

ICG(20 MHz bus)

6-ch. 16-bit Timer

2-ch. 16-bitTimer

16-ch. 10-bitADC

COP

POR

LVI

S08

Core

ICE+

BDM

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BLDC Motor Control Solutions

BLDC motor characteristic


Many Different Motor Types …

DC motor

AC induction motor

Brushless DC motor

Stepper motor (full step)

Stepper motor (half step)

Permanent magnet synchronous motor (PMSM)

Switched reluctance motor


Why BLDC Motor ?

►BLDC – BrushLess Direct Current motor

Low-cost and efficient drive for low-end

applicationsSensorless solution

using low-end microcontroller

High torque at start

++


BLDC Applications

►Appliance• Refrigerators• Washing machines

►Industry• Fans• High speed drives

►Automotive• Servo drives• Engine cooling fan• Electric vehicle

traction drive


BLDC Motor Characteristics

►Construction is reversed of a Standard DC Shunt Motor

• Magnet poles move (on the inside)• Field is stationary (on the outside)

►No Brushes• Commutation is performed by semiconductors

devices instead of brushes.• Requires 6 Active Devices FETs or IGBTs and 6

Fast Recovery Diodes which have a soft trrReverse Recovery

• Requires position sensing• Provides

No Carbon DustNo Arching or SparkingNo Brush or Commutator Wear Out


Trapezoidal Back-EMF

0 V

A

C B

• Trapezoidal Back-EMF• Trapezoidal Back-EMF A B C

A B C


Six-step commutation

ATOPABOTTOM

BTOP CTOP ATOPCBOTTOMBBOTTOM BBOTTOM

Desired Voltage

SwitchingSequence

VoltagePhase A

A

B

C

120o 60o

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Sensorless Solution Examples


Sensorless BLDC Solution

Sensorless BLDC Motor Control using MC56F8006Sensorless BLDC Motor Control using MC9S08AW60/AC60


BLDC Motor Theory

►BLDC motor rotates because of the magnetic attraction between the poles of the rotor and the opposite poles of the stator.

►If the rotor poles are facing poles of the opposite polarity on the stator, a strong magnetic attraction is set up between them.

►The mutual attraction locks the rotor and stator poles together, and the rotor is literally yanked into step with the revolving stator magnetic field.

axis of N pole of rotor

axis of S pole of stator

S S S S S

N N

NN

N

N

NN

NN

rotation N

S

S rotation



S S S S S

N N

NN

N

N N

NN

N

N

NN

NN

N

NN

NN

rotation N

S

S rotation

rotation



α

S S S S S

N NN

NN

N

NN

NN

NS

S

rotation

rotation



α

S S S S S

N NN

NN

N

NN

NN

NS

S

rotation

rotation

Figure 1- No-load condition

Figure 2- Load condition


Six Step BLDC Motor Control

►Voltage applied on two phases only►It creates 6 flux vectors►Phases are power based on rotor

position►The process is called Commutation

Power StagePhases voltage


Commutation example

Before commutation After commutation


Sensorless Back-EMF zero cross algorithm► Sensing voltage on disconnected phase

• When sensed voltage crosses half of DC bus voltage, the rotor is in middle between two commutation

• The detection of this zero crossing allows to detect rotor position


Application Diagram


MC56F8006 Peripheral Utilization & Software Structure

►Sensing PWM module• modulation for BLDC motor (complementary unipolar)

►Dual Timer• Channel 0: ADC run, stop, zero crossing evaluation• Channel 1: commutation

►PIT Timer• PI controllers, check manual interface, Ramp generation

►A/D Converter• DC Bus voltage, DC Bus current, Phase voltages

►Software Structure• 2x periodical interrupts (5ms, 6us)• 1x event interrupt (1x Commutation)• Background loop• Written in C language• Fast interrupt routines written in assembler


MC9S08AW60/AC60 Peripheral Utilization & Software Structure

►Timer 1• 6 channels: PWM modulation for BLDC motor (complementary bipolar)

►Timer 2• Time base for commutation period measurement• Channel 0: commutation• Channel 1: timing of application

►A/D Converter• DC Bus voltage, DC Bus current, Phase voltages, Heat sink temperature

►Software Structure• 2x periodical interrupts (1x 62.5 μs, 1x 5ms)• 2x event interrupt (1x Commutation, 1x Over current fault)• Background loop• Written in C language• Some arithmetic functions written in assembler


Application State Machine

INIT

STOP

Alignment

Start

RUN

ERROR

CPU RESET

run == 1

driver fault

run == 0

timer overflowdriver fault

alignmentFlag == 0

timer overflowdriver fault

run == 0

run == 0


Motor Start Up

►Alignment• The rotor is aligned to known position.

►Start up• Six forced commutation with predefined

timing. Then transition to sensorlessmode.

►Run• Motor is running sensorless in closed loop

Rotor alignment


Motor Start Up

Alignment

Start Up

Running

Stabilization(Optional)

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Tools, Resources and Summary

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Development Tools to Speed Time-to-Market► Demo Boards

► CodeWarrior™ Development Studio for 56800/E Digital Signal Controllers• Enables designers to build and deploy sophisticated DSC systems quickly and easily• IDE with optimizing C compiler, extensive SW libraries built into IDE• Processor Expert with free drivers and libraries• Instruction-set simulation• Free Special Edition with up to 32 KB code size [CWX-568-SE]

► FreeMASTER - remote real-time control and monitoring tool

► Accessories• USB Tap - JTAG to USB adaptor (CWH-UTP-ONCE-HE)• Motor control socket board (APMOTOR56F8000E) • Includes ultra-small 3-phase BLDC motor• MC56F80xx socket board (CPA56F8013)

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$99 MSRP

MC56F8006DEMO-T(USB Tap included)

$49 MSRP

MC56F8006DEMO

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Build things faster using Processor Expert

A rapid application design tool with …► Graphical user interface that allows an application to be specified by the functionality needed► Automatic code generator that creates tested, optimized C code tuned to the application

needs and selected Freescale MCU► Built-in knowledgebase that immediately flags resource conflicts and incorrect settings

Creating…► Hardware abstraction layer (HAL) – hardware-dependent, low-level drivers with a known

application programming interface (API)

Benefits► Eases migration between Freescale devices► Designers don’t have to be intimately familiar with every page of a specification► Errors are caught early in design cycle; therefore designers get to market faster with higher

quality product

Motor control library with Embedded Beans► Embedded Beans easily incorporate software components of Freescale’s motor control library► The Freescale motor control library includes

• Transcendental functions• PID controllers• Clark and Park transform and inverse transforms• Algorithmic support for space vector modulation, and more..

► Embedded Bean Store is now available at http://www.freescale.com/BeanStore

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FreeMASTER Interface

Application control and monitor

Real-time eTPU operation monitor

Live graphs, variable watches, and graphical control page

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System infrastructure

Application Implementation

User application SW

FMaster*support

On-chip driversefficient reflecting the chip feature

MC

cIB

Mot

or C

ontr

ol

AC

LIP

Adv

ance

d co

ntro

l

GFLIBGeneral functions

GDFLIBDigital filtering

FSL Library Set

External appl.*support

Doc

umen

tatio

n

On-chip peripherals

On-chip driver

Libraries

External HW

Pins

Application SW

Application

External connections

*optional

MC

56F8

0XX

TMFreescale Confidential Proprietary. Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2007. 37

Summary

►Advantages• Heat is generated in stator: easy to remove• High torque per frame size• Reliability due to absence of brushes and commutator• Highest efficiency. Renewed interest for “white goods”• Synchronous operation makes field orientation easy• Good high speed performance (no brush losses)• Precise speed monitoring and regulation poss

►Disadvantages• Rotor position sensing required for commutation.• Rotor construction requires banding in some applications.• More expensive system cost than brush DC motors.

www.freescale.com/motorcontrol

cost-effective sensor and sensorless brushless dc … motor control – market trends market trend...

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