TECHNICAL TRAINING 2008. Inverter Mini Chiller System and Control.

Technical Training 2008Technical Training 2008

TECHNICAL TRAINING TECHNICAL TRAINING

20082008


Inverter Mini Chiller Inverter Mini Chiller

System and ControlSystem and Control


1. Introduction1. Introduction

2. Basic Inverter Technology2. Basic Inverter Technology

3. Components3. Components

4. Control Algorithm4. Control Algorithm

5. Protection5. Protection

Content


Introduction


5ACV30 CR5ACV30 CR

5ACV55/75 CR5ACV55/75 CR

5ACV100/135/210 CR5ACV100/135/210 CR

Introduction


ModelModelCapacity (kW)Capacity (kW)

Cooling Cooling HeatingHeating

5ACV030CR5ACV030CR 7.947.94 9.669.66

5ACV055CR5ACV055CR 14.6514.65 16.1216.12

5ACV075CR5ACV075CR 20.5220.52 21.9921.99

5ACV100CR5ACV100CR 27.8027.80 29.3029.30

5ACV135CR5ACV135CR 38.5438.54 41.4741.47

5ACV210CR5ACV210CR 58.6258.62 61.5561.55

Introduction


Conventional Back to Back Circuits BPHE

Primary Circuit 1 Primary Circuit 2

Secondary Circuit

Primary Circuit 1 Primary Circuit 2

5ACV True Dual Circuits BPHE

New Technology BPHE- True Dual Circuits

Introduction


Conventional System

Inverter System

Inverter Compressor

Introduction


Inverter system provide constant Water Temperature band, or much lesser water temperature fluctuation. With this, water tank of mini chiller system can be eliminated

Elimination of Water Tank

A network up to 50 chillers in a system is possible. Control on the operation of chillers will be done through the microprocessor controller. The external water piping connection can be made either from the left or right side of the unit.

Modular Installation

• High & Low Pressure Switches • Anti Freeze Protection Sensor• Discharge Temperature Sensor• Over Pressure Relief Valve

Safety Protection• Water Pressure Differential Switch• Anti Freeze Heater on BPHE• Compressor, Water Pump Overload Protector

Introduction


Basic Inverter Technology


The system:-The system:-

Inverter

AC/DCRectifiert

u

t

Power supplyInput frequency50Hz t1

50 Hz 100 Hz 15 Hz

DC/ACInverter

(compressor motor input)

PWM



Three-phase inverter

PWM control

Power supply unit

Compressor

(Waveform formation)

AC Inverter Unit

Three-phase induction motor

AC ACDC

Temperature detection signal

Operating frequency signal



Inverter Basic StructureInverter Basic Structure

Inversion

PLC Control

Rectification

AC AC

DC Link Converter

PWM Signal

SMPS

M



Rectification CircuitRectification Circuit

• EMI filter to minimize emission effect (EMC) and raise EMI filter to minimize emission effect (EMC) and raise immunity level (EMS)immunity level (EMS)

• PTC to cushion start-up current to capacitorPTC to cushion start-up current to capacitor

• Diode bridge inverts AC to DCDiode bridge inverts AC to DC

EMI Filter

Rectifier Bridge

PTC Starter

Relay



DC StageDC Stage

• PFC capacitor acts to curb PF losses caused by DC voltage PFC capacitor acts to curb PF losses caused by DC voltage fluctuation in order to drive the asynchronous motorfluctuation in order to drive the asynchronous motor

Stabilizing Capacitor

Reactor

PFC Capacitor

Diode



Inversion CircuitInversion Circuit

• Consists of 6 IGBT (Insulated Gate Bipolar Transistor)Consists of 6 IGBT (Insulated Gate Bipolar Transistor)

• Controlling the ON/OF linkages, different frequency and voltage of 3-Controlling the ON/OF linkages, different frequency and voltage of 3-phase AC can be generatedphase AC can be generated

• IPM (Intelligent power module) encased the inversion circuitry together IPM (Intelligent power module) encased the inversion circuitry together with error detection and protection featureswith error detection and protection features



ItemItem Fixed Speed ACFixed Speed AC Inverter ACInverter AC

Energy SavingEnergy Saving NoNo Yes, by 30% - 40%Yes, by 30% - 40%

Temp. FluctuationTemp. Fluctuation ± 2°C± 2°C ± 0.5°C± 0.5°C

Adjust to LoadAdjust to Load NoNo YesYes

Start-upStart-up Current surge of 7-Current surge of 7-11x11x

Soft-start. No Soft-start. No current surgecurrent surge

Full Load Op.Full Load Op. NoNo Yes, operates at Yes, operates at high freq.high freq.

Speed of Cool/HeatSpeed of Cool/Heat SlowSlow FastFast

DefrostingDefrosting Less efficientLess efficient Accurate and fastAccurate and fast

Protection FeaturesProtection Features BasicBasic CompleteComplete

Auto-Mode FeaturesAuto-Mode Features BasicBasic CompleteComplete

Advantages of Inverter Air ConditionersAdvantages of Inverter Air Conditioners



Components


fan motors

Heat exchangers with gold fin as standard

Water pump

True dual circuits BPHE (Brazed plate heat exchanger)

Expansion tank ( 8L)

Control box assembly

Coil guardsFan guards

Components


Variable drive system compartment

Fixed drive system compartment

High pressure switch(NC) 600 psi – open, 480psi – close.

Low pressure switch(NC) 18 psi – open, 28 psi – close.

Pump OLP (overload protector)

Differential pressure switch

Over pressure relief valve

Anti freeze heater on BPHE

Compressor OLP (overload protector)

Chiller panel controller

Fixed speed scroll compressor (R410A)

Variable speed scroll compressor (R410A)

Components


Control box assembly IPM board(Intelligent power module)

Main board Magneticcontactors

EMI filter

Capacitor board

PFC capacitor(Power factor correction)

Uni-directional bridge diode

3 phase rectifier bridge diode

Fan capacitors

Power board

Components


Components

EMI Filter

Function• EMI Filter is a device placed between the power source and control device circuit.• Prevents external electromagnetic interference from getting into the controller.• Prevents internal electromagnetic emission from polluting the supply grid.


Main Board

For Model 55, 75, 100 & 135 For Model 30

Components


Power Board

- To convert rectified DC current +590VDC to respective desired voltages

- 12VDC relay- MCU +5VDC- IPM +15VDC

- Ensure stability of above voltages within power supply voltage fluctuation range (304-480 VAC)- Over voltage feedback- Output short circuit protection

Components


Capacitor Board

Components


IPM

Components

Function• Invert DC to AC current• Drive variable compressor

In-Built Protection• Low voltage lock-out• Over-heating, over-current and short-circuit protection.


Schematic Diagram

Condenser Coil 1

Acc

Acc

Liq Rvr

Liq Rvr

BPHE FS

Condenser Coil 2

DischTemp 2

(Disch Comp 2)

DischTemp 1

(Disch Comp 1)

InvComp

StdComp

SuctTemp

(Suction)

HP1

HP2

LP2

LP1

Cond InTemp 1

(Condenser)

Cond OutTemp 1

(Def Comp 1)

BPHE OutTemp

(BPHE Out)

BPHE InTemp

(BPHE In)

EWT (Water In)

LWT (Water Out)

Pump

Cond OutTemp 2

(Def Comp 2)

FilterDrier

Heating Cap Tube

Check valve

Cooling Cap Tube

Check valve

FilterDrier

EXV

O/A Temp(Outdoor Air)

Summary Pages-Screen 3

Display Menu-Defrost Sensor

Display Menu-Inverter Chiller

Display Menu-Discharge Sensor

5ACV100CR

4WV

4WV

Components


Control Algorithm


General Control Flow ChartGeneral Control Flow Chart

Start

No

Stop Inverter Comp

Yes

Stop pump

60s

Clash between current & selected

mode of operation?

Cooling mode

No

Heating?No

YesYes

Heating mode

System On?

Yes

Cooling?No10s

Stop Fixed Comp

Control Algorithm


Variable Drive Compressor ControlVariable Drive Compressor ControlCooling mode

Start up condition :

• Pump runs normally for 3 minutes *

• 2°C T water return – T set 4°C

• No irreversible errors in variable drive and the systems• Satisfy a delay of 3 minutes before restart #

Note : If fixed drive system starts first, the variable drive system should trail after 30 sec.

* Depends on Parameter P2 (flow switch alarm delay at pump start. Min 0s, max 199s, default 180s )# Depends on Parameter C2 (compressor min stop time. Min 0s, max 1990s, default 180s)

For example :Return water temp.= 14 to 16 °CSet temp = 12°C T = 2 to 4°C

Control Algorithm


Variable Drive Compressor ControlVariable Drive Compressor Control

Cooling mode selected water pump starts Outdoor fan starts variable drive compressor starts

Rated Freq.

55Hz

5Hz

t

3 min 5 sec 1 min

ONOFF

ONOFF

Variable drive comp

Outdoor fan

Outdoor fan will start 5 sec before compressor start

Inverter compressor will start from 5Hz to 55Hz and maintain this frequency for 1 min.

Increase to rated frequency with the rate of 1Hz/s5ACV100CR=75Hz

5ACV135CR=95Hz

Cooling mode

Control Algorithm


Variable Drive Compressor ControlVariable Drive Compressor ControlCooling mode

Shut down condition :

• Cooling mode terminates, OR

• T water return – T set -2°C

• Variable drive system error occurs, OR

For example :Return water temp.= 10°CSet temp = 12°C T = -2°C

Control Algorithm


Fixed Drive Compressor ControlFixed Drive Compressor ControlCooling mode

Start up condition :


• T water return – T set > 4°C

• No irreversible errors in fixed drive and the systems• Satisfy a delay of 3 minutes before restart #

Note : If variable drive system starts first, the fixed drive system will only start after the frequency of variable drive drops to 50Hz.


For example :Water return temp = 16°CSet temp = 12°CT = 4°C

Fixed drive starts first followed by variable drive

Control Algorithm



Cooling mode selected water pump starts Outdoor fan starts compressor starts


Fixed drive compressor starts

Fixed drive comp

Outdoor fan

1 min3 min 5 sec

ON

OFF

ON

OFF

Outdoor fan will stop after compressor has stopped for 1 min

Control Algorithm



Shut down condition :

• Cooling mode terminates, OR

• T set - T water return > 2°C and variable frequency drops pass 20Hz

• Fixed drive system error occurs, OR

For example :Set temp = 12°CWater return temp = 10°CT = 2°C

Control Algorithm


Variable Drive Compressor ControlVariable Drive Compressor ControlHeating modeStart up condition :


• 2°C T set - T water return 4°C

• No irreversible errors in variable drive and the systems• Satisfy a delay of 3 minutes before restart #


Note : If fixed drive system starts first, the variable drive system should trail after 30 sec.

For example :Set temp = 40°CReturn water temp.= 36 to 38 °C T = 2 to 4°C

Control Algorithm


Rated Freq.

45Hz

5Hz

t

3 min 10 sec 1 min

ONOFF

ONOFF

Variable drive comp

Outdoor fan

ONOFFVariable 4WV

5 sec

Variable Drive Compressor ControlVariable Drive Compressor ControlHeating modeHeating mode selected water pump starts Variable drive 4WV engages Outdoor fan starts compressor starts


Variable drive 4WV start 10 sec before compressor start

Inverter compressor will start from 5Hz to 45Hz and maintain this frequency for 1 min.

Increase to rated frequency with the rate of 1Hz/s

5ACV100CR=65Hz5ACV135CR=90Hz

Control Algorithm


Variable Drive Compressor ControlVariable Drive Compressor ControlHeating modeShut down condition :

• Heating mode terminates, OR

• T set - T water return -2°C

• Variable drive system error occurs, OR

For example :Set temp = 40°CWater return temp = 42°CT = -2°C

Control Algorithm


Fixed Drive Compressor ControlFixed Drive Compressor ControlHeating modeStart up condition :


• T set - T water return > 4°C

• No irreversible errors in fixed drive and the systems• Satisfy a delay of 3 minutes before restart #

Note : If variable drive system starts first, the fixed drive system will start after the variable drive frequency drops to 50Hz.


For example :Set temp = 40°CWater return temp = 36°CT = 4°C

Control Algorithm


Fixed Drive Compressor ControlFixed Drive Compressor ControlHeating modeHeating mode selected water pump starts Fixed drive 4WV engages Outdoor fan starts compressor starts


Fixed drive 4WV start 10 sec before compressor start

3 min 10 sec 1 min

ON

OFF

ON

OFF

Fixed drive comp

Outdoor fan

ON

OFFVariable 4WV 5 sec

Fixed drive compressor starts

Outdoor fan and 4WV will stop after compressor has stopped for 1 min

Control Algorithm


Fixed Drive Compressor ControlFixed Drive Compressor ControlHeating modeShut down condition :

• Heating mode terminates, OR

• T water return - T set > 2°C

• Fixed drive system error occurs, OR

For example :Water return temp = 42°CSet temp = 40°CT = 2°C

Control Algorithm


Pump ControlPump Control

Pump start up

When starting the system, pump will run for 3 minutes * before proceeding to next step.

* Depends on Parameter P2 (flow switch alarm delay at pump start. Min = 0s, Max = 199s, default = 120s)

Pump shut down

After both compressors shut down for 1 minute, pump shuts down.

Control Algorithm


Protection


Compressor Over-Current ProtectionCompressor Over-Current Protection

Variable drive compressor • When variable drive compressor current reaches the Ib, over-current protection triggers and the compressor frequency will reduce.• When the compressor current drops into Ic to Ib, frequency will not increase. • When the compressor current drops below the Id, frequency variation resumes.• When compressor current increase rapidly and reaches the Ia, the system will be determined as compressor overload and stop the compressor.

Ia

Ic

Variable compressor stops

Maintain frequency

Normal Operation

Comp amp (A)

IbFrequency step down

Id

Protection


Compressor Over-Current ProtectionCompressor Over-Current Protection

Variable drive compressor

Inv Inv Comp Comp

CurrentCurrent

M5ACVM5ACV030030

M5ACVM5ACV055055

M5ACVM5ACV075075

M5ACVM5ACV100100

M5ACVM5ACV135135

M5ACVM5ACV210210

IIaa 2929 20.520.5 20.520.5 20.520.5 20.520.5 20.520.5

IIbb 2727 1818 1818 1818 1818 1818

IIcc 2525 1717 1717 1717 1717 1717

IIdd 2525 1616 1616 1616 1616 1616

Protection


Compressor Over-Current ProtectionCompressor Over-Current ProtectionFix drive compressor • When fixed compressor current > Ie. The compressor will stops and resumes after 3 minutes

Note: When either drive overload protection occurs more than 3 times within 30 minutes, system triggers irreversible error protection.

Fixed compressor stopsComp amp

(A)

Ie

Model Ie

5ACV30 NA5ACV55 NA5ACV75 NA

5ACV100 165ACV135 305ACV210 ?

Protection


High Discharge Temperature ProtectionHigh Discharge Temperature ProtectionVariable drive system• When variable drive discharge temperature reaches 110°C, system stops.• When variable drive discharge temp. between 100°C and 110°C, frequency drops.• When variable drive discharge temperature is less than 97°C and more than 100°C, frequency increased restricted.• When discharge temperature falls below 94°C, normal operation resumes.

System shuts down

Frequency step down

Maintain frequency

Normal operation

Compressor dischargetemperature

110°C

100°C

97°C94°C

Protection


High Discharge Temperature ProtectionHigh Discharge Temperature Protection

Fixed drive system• When fixed drive discharge temperature reaches 110°C, system stops.• When discharge temperature falls below 94°C for 3 minutes, system resumes.

Td = Compressor discharge temperature

110°C

94°CComp start

Comp Cut

3 min

Td

Protection


Outdoor Coil High Temperature ProtectionOutdoor Coil High Temperature Protection

Variable drive system• During cooling, when Tcoil1 > 60 °C, frequency drops.• During cooling, when Tcoil1 < 55 °C, system resumes.

Fixed drive system• During cooling, when Tcoil2 > 64°C, compressor stops.• During cooling, when Tcoil2 < 51°C, system resumes.

Protection


Low Pressure Switch ProtectionLow Pressure Switch Protection

• Alarm delayed at compressor startup : 30 sec depends on Parameter P3*.• No protection during defrosting.• If variable drive or fixed drive low pressure switch is activated for 5 seconds, alarm will be triggered.* Parameter P3 (Low pressure alarm delay at compressor start up. Min=0s, max=199s, default=30s)

Note : If low pressure alarm occur more than 3 times within 30 minutes, system shuts down to irreversible error.

Protection


High Pressure Switch ProtectionHigh Pressure Switch Protection

• If fixed drive high pressure switch is activated for 30 sec, alarm will be triggered.• If variable drive high pressure switch is activated, frequency of variable drive compressor will decrease at 1Hz/s. If it is re-activated for 30 sec, alarm will be triggered.

Note : If high pressure alarm occur more than 3 times within 30 minutes, system shuts down to irreversible error.

Protection


If 3 phase AC phase sequence is incorrectly connected, system will not start and controller will indicate error. System will resume after rectification. (except M5ACV030CR)

If phase missing happens, system will not operate. Controller will indicate error. System will resume after rectification.

3 Phase AC Phase Sequence Protection

3 Phase AC Phase Missing Protection

Protection


Thank YouThank You

TECHNICAL TRAINING 2008. Inverter Mini Chiller System and Control.

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Transcript of TECHNICAL TRAINING 2008. Inverter Mini Chiller System and Control.