ST72141 BLDC Inverter AirCondition Demo Kit

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ST72141 BLDC InverterAir-Condition Demo Kit

• Feb 2004

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ST72141 Air-Condition Demo Kit Presentation
Contents

• A.Inverter Air-Condition Background
• B. BLDC Motor Basics
• C. ST72141 Air-Condition solution description
• - whole Air-Condition Demo Kit
• - Indoor unit
• - outdoor unit
• - Summary of Benefits of ST72141 solution
• D. How to start with ST Air-Condition Demo Kit

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Air-Condition system

• Air-condition Compressor, 4 way valve, fan,
  evaporator, condenser
• 4-way valve control cool or heat mode

Cool mode
Heat mode
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Inverter Air-Condition Background (1)

• Environment Friendly
• Reduce waste of energy Variable Refrigerant Flow
  Air-Conditioners and Refrigerators provide energy
  saving of up to 40
• The electricity demand increases faster than
  electricity supply Governments are implementing
  regulations to save on electric equipments
  efficiency
• 95 of Japanese household use Inverter
• air-conditioner
• Enhanced Comfort Performance
• Create friendly user interfaces
• fine temperature regulation
• Inspect whole Air-Condition system

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Inverter Air-Condition Background (2)

• Inverter Air-Condition Benefit
• Lower electricity consumption
• Fast get target temperature
• Stable reliable temperature control
• Silent operation

US
SEMI-CONDUCTOR DRIVE
ELECTRO-MECHANICAL DRIVE
VARIABLE FREQUENCY (3-phase Brushless DC
Compressor)
MCU DRIVER IGBT
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FIXED FREQUENCY (Single phase Induction
Compressor)
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BI-METAL THERMOSTAT
Efficiency
2
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Inverter Air-Condition Background (3)

• Inverter Air-Condition in China Market

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Inverter Air-Condition Background (4)

• 3Ph. Brushless Motors Explosive Growth

Source Forward Concepts 2000 and Motorola
Semiconductor Products
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ST72141 Air-Condition Demo Kit Presentation
Contents

• A.Inverter Air-Condition Background
• B. BLDC Motor Basics
• C. ST72141 Air-Condition solution description
• - whole Air-Condition Demo Kit
• - Indoor unit
• - outdoor unit
• - Summary of Benefits of ST72141 solution
• D. How to start with ST Air-Condition Demo Kit

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BLDC Motor Basics (Generalities)

• Also called brushless Permanent Magnet DC (BLDC)
  or synchronous DC motor
• Advantages
• High efficiency (up to 98)
• Variable speed
• Silent operation
• Reliable/long life time (no brushes)
• High Size/Power ratio
• High torque at start-up
• Same stator as Induction 3 phase motor
• Drawbacks
• Overall system cost due to cost of electronic
  control

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PMDC Basics (1)

• Operating principle
• Synchronous Stator flux and rotor mechanical
  rotation speed are same.
• Stator description 3 phase winding (1 or 2 or
  more pairs of poles)
• Rotor description Permanent magnet
• For 1 pair of pole 1 electrical cycle (6 steps)
  1 mechanical cycle

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One pair pole motor
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PMDC Basics (2)

• Drive mode 6 steps Principle

Current in winding A,B,C
300V DC
T1
T5
T3
A
U
V
B
W
C
2
T4
T6
T2
-
T1 T1 T3 T3 T5 T5 T4 T6 T6 T2 T2 T4
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PMDC Basics (3)

• Control Method
• It requires to know the position of the rotor at
  all timesin order to reach the status of auto
  commutation (best efficiency). At least 2 common
  ways are available to know the rotor position.
• Hall effect sensors (sensor mode)
• Back emf (1) detection (sensorless mode)
• The autocommutation happens when the current in a
  winding is in phase with the b-emf in this same
  winding.
• The control process will be about keeping these
  2 signals in phase
• Current generated by inverter in the motor
  windings
• Back-emf Voltage induced (by Permanent Magnet) in
  the motor windings

• (1) B-emf is the voltage induced in a winding by
  the movement of the magnet in from of this
  winding edj/dt. It is independant of
  the energy supply to the motor (just by spinning
  by hand the rotor for example it is
  possible to generate back-emf).

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Implementation of control B-emf detection
Conventional Method (1)
300V
BUS
BUS
divider filter
N
N
5V
N
N'
N'
POWER GND
POWER GND
POWER GND
virtual ground
weaknesses - Voltage dividers give reduced
sensitivity difficulty for low speed operation
- Filtering is optimised for narrow speed
range
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Implementation of control ST72141 patented
Sensorless method
300V
T1 PWM "ON"
A
V/2
B
C
bemf
T4 always ON
GND

• back-EMF whole signal sensing
• high sensitivity large speed range very
  low speed operation starting with full torque
• no filtering delay
• high signal to noise ratio

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ST7141 Back-emf detection Patent
NO PATENT INFRINGMENT REDUCED COST
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ST72141 Air-Condition Demo Kit Presentation
Contents
A.Inverter Air-Condition Background B. BLDC Motor
Basics C. ST72141 Air-Condition solution
description - whole Air-Condition Demo Kit -
Indoor unit - outdoor unit - Summary of
Benefits of ST72141 solution D. How to start with
ST Air-Condition Demo Kit
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whole Air-Condition Demo Kit

• Features
• - Full Air-Condition Solution - Fuzzy Control
  Temperature
• - 24V BLDC Motor (Extend - KANDA KIT
  Air-Condition mode
• to real compressor with HV Board)

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Air-Condition Demo Kit Control Unit
Indoor UNIT ST72324
Air-Condition Indoor Unit

• Indoor Unit
• - LED display
• - Infrared remote controller signal
• - 2 Temperature Sensor
• - Fan PG motor
• - Swing stepper motor
• - Buzzer
• - UART communication
• Outdoor Unit
• - 3 Temperature Sensor
• - Current Voltage Sensor
• - Compressor(BLDC motor)
• - 4-way Valve
• - Outdoor cooling Fan motor
• - LED display
• - UART communication

Display
Main Relay
Buzzer
Remote controller
PG Motor
Environment Temperature Sensor
Fan
Stepper Motor
Evaporator Temperature Sensor
Swing
SCI Communication
Environment Temperature Sensor

• Outdoor UNIT
• ST72141

Fan
Condenser Temperature Sensor
4-way valve
Compressor outlet Temperature Sensor
IGBT or IPM
Current Sensor
Voltage Sensor
BLDC Motor Compressor
Air-Condition Outdoor Unit
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Air-con running mode and functions

• Air-con running mode and functions

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ST72141 Air-Condition Demo Kit Presentation
Contents
A.Inverter Air-Condition Background B. BLDC Motor
Basics C. ST72141 Air-Condition solution
description - whole Air-Condition Demo Kit -
Indoor unit - outdoor unit - Summary of
Benefits of ST72141 solution D. How to start with
ST Air-Condition Demo Kit
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Low Cost High efficiency Digital Control

• Features
• 5 Mode Cool, Heat, Auto etc.
• Full function sleep, Timer etc.
• Infrared remote control
• Fuzzy Temperature Regulation
• Compressor Frequency display
• Accurate Fan Motor control
• C language

• Main Components
• MCU ST72324
• Switch kit Triac,ULN2003
• L7805?L7812
• LED display, Buzzer, Relay, etc.
• ST72324 Features
• 8K to 32K Flash
• PLL for 2x frequency multiplication
• SCI SPI communication interface
• 42/44 Pin, 32/24 multifunctional I/O
• 10-bit ADC

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Whole Air-Condition function

• Indoor Unit Topology

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Fan PG motor control Phase Angle Control

• Fine control feature
• Accurate Fan speed controlPI
• Speed detection TimerINT
• Zero crossing detection Timer INT

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Communication SCI

• Feature
• Half-duplex Uart, Master/Slave
• 1K baud rate
• 8 data bits,1 start bit ,1 stop bit per byte
• Communication Topology

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Indoor Unit Application
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ST72141 Air-Condition Demo Kit Presentation
Contents
A.Inverter Air-Condition Background B. BLDC Motor
Basics C. ST72141 Air-Condition solution
description - whole Air-Condition Demo Kit -
Indoor unit - outdoor unit - Summary of
Benefits of ST72141 solution D. How to start with
ST Air-Condition Demo Kit
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The complete Kit for 3 Phase Motor drive

• FEATURES
• Variable Speed or test mode
• Enhanced Digital Speed Regulation
• Compressor protect (CUR , VOL, IPM etc.)
• Auto-defrost

• COMPONENTS
• ST72141 MTC, 34pins, 8K OTP/ROM
• Three L6368 power interface drivers
• Six STGWNB60 IGBTs power drive
• Viper12 non isolated supply

INVERTER
Bridge Rectifier
L638X
L638X
L638X
STBR408 STBR608
L6386
STGW20NB60HD
LED
4Way valve
Cooling Fan
Sensors
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ST72141 Summary

• ST72141 Feature Set
• 8K ROM/OTP/EPROM
• 14 multi functional bidirectional I/Os with
  external interrupt
• Two 16-bit Timers with
• 2 input captures 2 output compares External
  clock input PWM and pulse generator mode
• SPI synchronous serial interface
• 8-bit ADC with 8 channels
• SDIP32 or SO34 package
• Enhanced reset (on-chip) system
• Low voltage supervisor
• 3 power saving modes
• Configurable watchdog reset

• Motor Control Cell
• Commutation step control Voltage mode /
  Current mode
• Sensor or Sensor-less motor phase commutation
• Back-EMF zero-crossing detection (as low as
  200mV)
• Real time motor winding demagnetization detection
  for fine-tuning the phase voltage masking time to
  be applied before back-EMF monitoring
• Automatic and programmable delay between back-EMF
  zero crossing detection and motor phase
  commutation

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Outdoor Unit Application
BLDC Motor Speed Control (PI)
Init Main loop
LED, Fan 4way valve Relay etc.
Communication Set send Data Receive data decode
Err detection etc.
VOL, CUR Protection etc
Set target speed
ADC
C,D event Handle
Ports
PWM Duty cycle
BEMF Detection
Timer and INT
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Sensorless starting procedure

• 1/ Define a rotor starting position
• ex phase A is grounded, starting current is
  risen into phase BC simultaneously
• 2/ Define a constant acceleration starting ramp
• First step-time and acceleration are depending on
  system inertia motor torque (see example here
  below)

• 3/ Start by positioning the rotor (typically few
  100msec), then increase the current (torque) and
  sequence phase configuration according to
  step-time ramp enable b-emf detection from
  beginning, wait for two successive detection
  before to swap to auto-commutated mode

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Control Principles of PMDC Maximum efficiency
with delay manager
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ST72141 Regulation loops(simplified diagram)
Target Motor Speed
Step Time
Motor
P.I.D or Fuzzy regulation
b. emf
I
Feedback Speed
Motor efficiency regulation loop
Speed regulation loop
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ST72141 Air-Condition Demo Kit Presentation
Contents
A.Inverter Air-Condition Background B. BLDC Motor
Basics C. ST72141 Air-Condition solution
description - whole Air-Condition Demo Kit -
Indoor unit - outdoor unit - Summary of
Benefits of ST72141 solution D. How to start with
ST Air-Condition Demo Kit
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Benefits of ST72141 solution(1)

• Patented Sensor Less back-EMF Control method
• Only 3 standard resistors as external components
  for back-emf sensing
• Embedded current loop and reset circuit
  minimises external components
• Suitable for motors from 12V to 300V
• Allows Voltage and Current mode control of Motors
• Hardware Co-processor with an Industry standard
  8bit MCU
• 8bit core accessibility, fast learning curve and
  time to market
• Short and Low project development cost.
• Low power consumption of MCU (15mA) allows for
  smaller supply than DSP
• 8Mhz clock frequency generates lower EMI than DSP
  running at 20 or 40MHz
• Internal HW 8bit multiplier and divider (70 of
  CPU resources free)
• Allows running of your own BLDC in a few minutes
  with KANDA mode.

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Benefits of ST72141 solution(2)

• Cost Effective Appliances
• Lower cost than available DSP offer
• Dedicated Motor Control cell to free CPU
  resources
• C language( indoor unit) .Short and Low project
  development cost.
• User Friendly
• Air-Condition status display Interfaces
• Auto-defrost
• Enhanced warning visuals
• Extended Reliability
• IGBT or IPM error detection
• compressor over current protection
• compressor over temperature protection

• Enhanced Comfort Performance
• Stable reliable temperature control 1?
• Compressor frequency control 1Hz
• Fan motors speed 15RPM
• voltage range145VAC to 270VAC
• running frequency range 30HZ to 100HZ
• TECHNICAL SUPPORT
• Dedicated Application Support
• High performance C Compiler
• Emulator/programmers
• Application Notes
• Reference SW

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ST72141 Air-Condition Demo Kit Presentation
Contents
A.Inverter Air-Condition Background B. BLDC Motor
Basics C. ST72141 Air-Condition solution
description - whole Air-Condition Demo Kit -
Indoor unit - outdoor unit - Summary of
Benefits of ST72141 solution D. How to start with
ST Air-Condition Demo Kit
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How to Start with 3-phase Compressor ?

• ST7MTC2/xx Kanda kit (www.kanda.com)
• 24V motor, control board, power board
• PC SW, assembler SW
• Aplication builder, programmer board
• Advised Resale 695
• ST7TMC2/PS high voltage power stage
  (www.kanda.com)
• Spare 300V power board for high voltage
  applications
• Emulator / Programmer
• Application notes (www.st.com)
• ST72141 related AN subjects basics of sensor
  less BLDC , ST72141 motor control cell, ST72141
  SW, PWM management, start-up algorithm, demo-kit
  operation,
• AN numbers 1130, 1082, 1083, 1129, 1276,
  AIR-Condition controller, Specification ,user
  manual
• Standard SW (contact ST)
• Dedicated Refrigerator compressor design-aids
  (contact ST)
• AN1238 REFRIGIRATOR 3-PHASE COMPRESSOR WITH
  ST72141
• Standard Software to run 3-phase Compressors with
  4 or 6 pair of poles using the Kanda kit
• ST Technical Support

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Air-Condition or KANDA KIT MODE
DC24V BLDC Motor
KANDA KIT Mode
HV(DC300V) BOARD
Outdoor control board
INDOOR CONTROL BOARD
Air-Condition
ST72141-EPB
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ST7MTC2 Motor Controller Kit
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3 Phase Brush Less Motors

• Electronically controlled, brushless motors with
  inverter are becoming increasingly popular.
• They have significant advantages versus universal
  and single phase induction motors
• INVERTER A three half-bridge configuration to go
  from single phase, fixed frequency mains to 3
  phase, variable frequency inverted current
• INDUCTION motor or BLDC Motor ?

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ST MICROELECTRONICS,YOUR ADVANTAGE FOR

• LOWEST COST, HIGHLY RELIABLE, HIGH PERFORMANCE
  and DIGITAL CONTROLS