Air-Conditioner Reference Design

2

Where We Fit?

Air Conditioner Indoor Unit

Air Conditioner Outdoor Unit and HVAC

3

Air Conditioner

Market Trends

⚫ Inverter based air conditioner

⚫ Variable speed drive enables continuous temperature

regulation and are more efficient compared to fixed

speed operation

⚫ BLDC compressor for higher energy efficiency

⚫ Proven solution for 1KW to 2KW PFC, sensor

less Field Oriented Control (FOC) & torque

compensation

⚫ Compact form factor

⚫ Cost optimized turnkey solution

4

Aircon Reference Design

Features

⚫ Implements PFC, compressor motor control and fan motor control

Benefits

⚫ Targets higher Energy Efficiency Ratings (EER)

⚫ Single chip solution for cost optimization

⚫ Separates application and PFC code development from dual motor

control code using the two cores in dsPIC33CH DSC

Design Code Separately and Integrate Seamlessly

⚫ Total input power of up to 1.8KW

⚫ 4 temperature sensors connection

⚫ Communication with indoor unit

⚫ Optional support for ACIM and

BLDC motor with built-in drive

5

Block Diagram

Bridge

Rectifier

Interleaved

PFC

3 Phase

IPM

3 Phase

Discreet

IGBT

Power

Stage

EMI

Filter

Gate

DriverMCP14E4

230VAC

EEPROMAT24C512C

Over Current &

Voltage Protection

MCP6541/2

7×Current &

voltage Sense

MCP6V92

VDC

3.3V

Aux

Power

15V

LDOMCP1826

12VVDC

Relay RelayField

Communication

Indoor

UnitValve/ACIM

Control

3×

Temp Sense

Ambient

Condenser

Discharge

Suction

Condenser Fan

Compressor

Driver

Stepper

Motor

Electronic

Expansion

Valve Microchip Components

2×

6

Specification

SectionsDesigned

power (W)

Tested

power (W)

Input voltage140V to 280V,

50/ 60 Hz

140V to 240V,

60 Hz

PFC input 1800 1600#

PFC output 1620 1520

Compressor drive input 1490 1350*

Compressor drive output 1341 1300

Fan drive input 130 130**

Fan drive output 117 117**

* Back calculated based on PFC efficiency and input power drawn

** Based on Input power – no results on power analyzer

# Based on maximum load availability

7

Air-Conditioner Reference Design Board

8

Test Setup

9

Test Setup

S.No. Item Make and Part Number

1 Air conditioner unit Supplied by customer

2 Controlled power supply Chroma 61604

3 Power analyzer Hioki PW6001

4 Oscilloscope Keysight MSOX3054T

5 Current probe Keysight 1147B

6 Air conditioner reference board Microchip reference design

10

PFC Section

⚫ Implemented in master core of

dsPIC33CH128MP508

⚫ Active interleaved PFC

⚫ Efficiency > 93%

⚫ THD < 5% above 50% load

⚫ Power factor > 0.95 above 50% load

⚫ Switching frequency 64 kHz

⚫ IGBT and diode from ROHM

⚫ Gate driver from Microchip

Bridge

RectifierInterleaved

PFC

EMI

Filter

Gate

DriverMCP14E4

230VAC

11

PFC Test Results – Diff

Diode, IGBT Combination

* Tested with resistive load

12

Compressor Section

Compressor Motor

⚫ Supports PMSM or IPMSM

⚫ dsPIC33CH128MP208 slave

core for motor control

⚫ Up to 1.4KW inverter stage

⚫ 4 to 20kHz switching frequency

Sensorless

FOCVariable

Speed

Control

Field

Weakening

Stall Detection

Torque

CompensationImplemented

Motor Control

Algorithms

Interleaved

PFC

3 Phase

IPM

Gate

DriverMCP14E4

Over Current &

Voltage Protection

MCP6541/2

7×Current &

voltage Sense

MCP6V92

VDC

3×

Compressor

PLL EstimatorMTPA for

IPMSM

13

Test Results – with PFC &

Compressor Motor

* Board efficiency: PFC input and drive output

14

Outdoor Unit Fan Section

Fan Motor

⚫ Supports PMSM or IPMSM

⚫ dsPIC33CH128MP slave

core for motor control

⚫ 150W power stage

⚫ 20kHz switching frequency

Interleaved

PFC

3 Phase

Discreet

IGBT

Power

Stage

Gate

DriverMCP14E4

Over Current &

Voltage Protection

MCP6541/2

7×Current &

voltage Sense

MCP6V92

VDC

3×

Fan

Sensorless

FOCVariable

Speed

Control Stall Detection

w/ Recovery

Wind-MillingImplemented

Motor Control

Algorithms PLL EstimatorMTPA for

IPMSM

15

dsPIC33 DSC Roadmap

70 MIPS 3V/5V

Fe

atu

res

/Mem

ory

dsPIC33EP512MC

32 - 512KB Flash

4 - 48KB RAMOp-Amps, CAN

3V, Functional Safety28/36/44/64 pins

100 MIPS Single/Dual Core

dsPIC33EV256GM

32 - 256KB ECC Flash

4 - 16KB RAM

Op-Amps, CAN, SENT

5V, Functional Safety

28/44/64 pins

dsPIC33CH128MP

64 - 128KB ECC Flash

20KB RAM

Dual Core, Dual Motor

DACs, PGAs, CAN-FD

28/36/48/64/80 pins

dsPIC33CH512MP

256 - 512KB ECC Flash

48 - 72KB RAM BIST

Dual Core, Dual Motor

DACs, PGAs, 2xCAN-FD

48/64/80 pin

dsPIC33CK256MP

32 - 256KB ECC Flash

8 - 24KB RAM

Single Core, DACs

Op-Amps, CAN-FD

28/36/48/64/80 pins

dsPIC33CK64MP

32 - 64KB Flash, ECC

8KB RAM

Single Core, DACs

Op-Amps, SENT

28/36/48 pins

Ideal DSCs for

Aircon Design

16

dsPIC33CH Block Diagram

Peripheral Tigger Gen (1)

SMPS/MC PWM (4 Ch.)

ADC (1x 12-bit, 16 Ch.)

Analog Comparator (1)

I2C (2)

CAN-FD

UART (2)

SPI (2)

SENT (2)

Timers

Capture/Comp/

PWM (8)

Configurable

Logic Cell

MEMORY BUS

PE

RIP

HE

RA

L B

US

MASTER

Core

dsPIC33C

90 MIPS

5 Reg Set 5 ACC Set

SMPS/MC PWM (8 Ch.)

ADC (3x 12-bit, 18 Ch.)

Analog Comparator (3)

PGA (3)

I2C (1)

SPI

UART

Configurable

Logic Cell

Capture/Comp/

PWM (4)

Timers

MEMORY BUS

PE

RIP

HE

RA

L B

US

SLAVE

Core

dsPIC33C

100 MIPS

5 ACC Set5 Reg Set

128 KB

ECC Flash

16 KB

Data RAMDMA (6)

24 KB

ECC PRAM

4 KB

Data RAMDMA (2)

Mailboxes

FIFO

FIFO

WDT & DMT WDT

17

Target Markets

Air Conditioner

Refrigerator

Washing Machine Dish Washer

PFC Power Supplies

18

Enabling Aircon Customers

⚫ Schematics, BoM and PCB design files

⚫ Firmware implementation for PFC and dual motor control

⚫ User’s guide and application note

⚫ Demo boards are available on loan to qualified customers

⚫ Refence design webpage: www.microchip.com/aircon

Complete solution for Air-Conditioner Outdoor Unit

http://www.microchip.com/aircon

19

Summary

SLAVE

Core

dsPIC33CH

100 MIPS

MASTER

Core

dsPIC33CH

90 MIPS

Power Factor

Correction Fan Compressor

IPC

A solution that reduces three devices to one

⚫ Air Conditioner Reference Design based on

Dual Core dsPIC33CH DSCs

⚫ Platform for developing high voltage power

systems (1.8KW) with PFC for white goods

⚫ Integrates PFC and dual motor

control into a single chip for

cost effectiveness

⚫ Implements sophisticated

motor control algorithms for

high efficiency