Universidad de Oviedo, E&E Eng. Dept. Industrial ...

05/sep/2008

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An Introduction to Efficient Lighting

J. Marcos Alonso

University of Oviedo, Asturias Spain

Universidad de Oviedo, E&E Eng. Dept.Industrial Electronics and Lighting Group

Viesques Campus, Gijón

Asturias

The City of Gijón

05/sep/2008

2

Universidad de Oviedo, E&E Eng. Dept.Industrial Electronics and Lighting Group

C iGroup Members:2 Full Professors 5 Associate Professors4 Ph. D. Students5 M.Sc. Students

Companies:

Outline

IntroductionLampsBallastsDigital ControlConclusions

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First idea:Light accounts for nearly 25% of the electrical energy consumption in the industrialized world

Introduction

Europe South America

Percentage of energy use in commercial buildings by end user

Introduction

Lighting is a nice piece of the pie

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Some Basic ConceptsIntroduction

Electromagnetic Spectrum100

Human’s Eye Response

ElectricLighting

100 380 770

50

0

λ [nm]

V(λ) P(λ)EYE RESPONSE

Power(W)

RadiatedPower

LightingPower

Non-LightingPower

Heat Losses

CorrectedLightingPower(Lumen)

Select the adequate light source for each applicationIncandescentDischarge

IntroductionBasic hints for energy saving in lighting:

Select the adequate auxiliary equipment:Magnetic ballastElectronic ballastDimming circuit

Select the adequate control strategy:Select the adequate control strategy:SchedulingTask tuningDaylightingLumen maintenancePresence detection …

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Some countries are already taking actions:Introduction

Australia

Traditional light bulbs will be banned by 2010 in AustraliaThis will lead to a reduction of 800.000 tons of CO2 per yearTotal CO2 produced annually in the world is 564 Mtons (2004)

IntroductionEuropean Union

The least efficient lamps will be phased-out from the European market by 2015The industry will have to switch to energy saving CFL or high-efficient halogen lampshalogen lamps

As a result (future):Reduction of 23 M tons of CO2 emission per year63,000 GWh of energy saved per year

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Outline


Evolution of Lighting in HistoryLamps

Solid State

Solid state is not yet a full mature technologyThe most efficient and long-lasting lamps are still based on electrical discharge

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Lamps

Incandescent LampsLamps

100P( λ )

mWnm

P( λ )

mWnm

Typical EmissionResponse

100 1.000 10.000380 770

50

0

λ [nm ]

nmnm

40.001.53.803Carbon

0.0419.13.668Tungsten

0.0188.91.367

RESISTIVITY 20ºC

DENSITY[gr/cm3]

MELTING TEMP.[K]

MATERIAL

40.001.53.803

0.0419.13.668

0.0188.91.367Copper

[gr/cm3][K]

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Lamps

Filli

Incandescent Lamps

Filling gas:Vacum for P< 40WN + Ar, Kr, Xe: P>40W

Tugnsten (Wolfram) Filament

BASIC CHARACTERISTICS:

1.- Instant Ignition2.- Very Good Color Rendering Index (CRI) 3.- Low Luminous Efficacy: 10-20 lm/W4.- Short Life: 1000-2000 hours

Lamps

Incandescent Lamps

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Discharge LampsLamps

Elastic Collision

Free Electron Free Electron

Ionization

Radiation

Heat GenerationTemp. Increase

Free Electron GenerationDischarge

Free Electron

Generation of RadiationLight

Fluorescent LampLamps

Light

Basic Operation

Excitation

Ionization

Radiation UV

PhosphorCoating TubeElectrode Mercury

AtomAtom


1.- Operation at 0.8-1 atm.2.- Good Color Rendering Index (CRI) 3.- High Efficacy: 60-00 lm/W4.- Long Life: 10,000 hours

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Compact LampsLinear Lamps

Lamps

T12T8

T5T3

T12: 38 mmT8: 25 mmT5: 15 mmT3: 9 mm

Compact Fluorescent LampsLamps

With Integrated BallastThey are a direct replacement

For Incandescent Lampsp

Recommended for lighting points with burning hours higher than 1 hour per day continuously

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Compact Fluorescent LampsLamps

With Integrated Ballast

Many different models, with different functionalities, are available

Expected Payback Time in Years for CFLLamps

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High Pressure Mercury Vapor LampsLamps

⎥⎦⎤

⎢⎣⎡

WLmη

40

60

Mercury Vapor

HPMVFluorescent

P [Pa]1 104102 106

20

40

Spectrum

Fluorescent

350 400 450 500 550 600 650 700 750λ [nm]


1.- Operation at 2-4 atm.2.- Poor Color Rendering Index (CRI) 3.- Good Efficacy: 25-60 lm/W4.- Long Life: 15,000 hours

Metal Halide LampsLamps

⎥⎦⎤

⎢⎣⎡

WLmη

40

60

Mercury Vapor + M. Halides

P [Pa]1 104102 106

20

40

Spectrum

BASIC CHARACTERISTICS:1.- Incorporate Metal Halides (Tl, Dy, Sc, etc.)2.- Very Good Color Rendering Index (CRI) 3.- Good Efficacy: 80 lm/W4.- Medium Life: 6,000 hours

350 400 450 500 550 600 650 700 750λ [nm]

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High Pressure Sodium Vapor LampsLamps

Sodium Vapor100

80

LuminousEfficacy[%] Low

Pressure

Spectrum

60

40

20

1 10 100 1.000 10.000

Discharge Pressure (Pa)

100.000

STANDARD (IRC 20)IRC 60

IRC 80HighPressure


1.- Operation at 7-100 kPa2.- Medium Color Rendering Index (CRI) 3.- Good Efficacy: 50-120 lm/W4.- Long Life: 20,000 hours

350 400 450 500 550 600 650 700 750λ [nm]

HPSCRI=60

Low Pressure Sodium Vapor LampsLamps

Sodium Vapor100

80

60

LuminousEfficacy[%] Low

Pressure

LPS

60

40

20

1 10 100 1.000 10.000

Discharge Pressure (Pa)

100.000

STANDARD (IRC 20)IRC 60

IRC 80HighPressure

Spectrum

350 400 450 500 550 600 650 700 750λ [nm]

LPS


1.- Operation at 0.4 Pa2.- Very Poor Color Rendering Index (CRI) 3.- Very Good Efficacy: 60-150 lm/W4.- Long Life: 15,000 hours

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Consumption Distribution Lamps

About 70% of artificial lighting is generated by discharge lamps80% of energy consumption is professional lighting

Future Light Sources: LEDsEvolution of Light Sources: Status Quo 2007

Lamps

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Future Light Sources: LEDsLamps

60

70

Nominal Datasheet Flux (350mA @Tj=25 C) vs. Useable Light Flux

0

10

20

30

40

50

60Lu

men

LuxeonK2

LuxeonI

Cree Osram Nichia SeoulSemi

NominalUseable

Outline


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Typical Electrical Circuit: FLBallasts

BALLAST(CHOKE)

GLOWSWITCH

ACMAINS

SWITCH

Typical WaveformsTypical WaveformsVoltage

Current

Ballast and Igniter for HPS LampBallasts

3-5 KV – ton=50 μS

Ballast Igniter Capacitor

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Ballast and Igniter for MH LampBallasts

7-12 KV – ton= 0.5 μs

Ballast Igniter Lamp

High Frequency OperationFluorescent

(Low Pressure Mercury)

Ballasts

Low Pressure Sodium

100

110

120

LUMINOUSFLUX[%]

100

115

LUMINOUSFLUX[%]

50 100 K 3 M

FREQUENCY[Hz]

50 25K 400K100KFREQUENCY

[Hz]

In these lamps the increase of frequency provides and increase of luminous efficacy

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Electronic Ballast Vs. Magnetic BallastsBallasts

Operation at low frequencyOperation at low frequencyHigh losses, poor efficiencyStroboscopic effectAcoustic noise (humming)High volume and weight

Operation at high frequencyLow losses good efficiencyLow losses, good efficiencyNo Stroboscopic effectNo Acoustic noiseLow volume and weight

Market share of ballastBallasts

The market share of electronic ballasts is growing: From 24 % in 2000 to 31% in 2004

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Typical Circuit of Electronic BallastBallasts

Rectifier Inverter Filter(Tank) Lamp

MainAC

(Tank)

50 Hz DC 50 kHz 50 kHz

Electronic Ballast Design

C L

LCC Resonant TankVIGNITION

Ignition

Heating

Ballasts

RLA

CS

CP

L

VS

VHEATING

VLAMP

Q=RLA/ZB

Q~

Q~

Running

Heating

Lamp:VLA=30Vrsm ILA=0.8Arms

RLA=37.5 Ω

ΩR

Q RLA/ZB

ΩIG ΩH

An LCC resonant tank is used to ignite and supply the lampA soft-starting strategy is implemented in order to increase lamp’s life

RunningLA

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HeatingV

+CS

L

VHIHCP

IHIH

Ballasts

The frequency needed for a given heating current IH is:

2

21

2 ⎟⎟⎠

⎞⎜⎜⎝

⎛++=Ω

HB

S

HB

SH IZ

VIZ

V

The heating voltage at this operating point: 12 −Ω=

H

SH

VV α

VS -P

IgnitionIgnitionThe ignition voltage is obtained at the following frequency:

IG

SIG V

Vα+=Ω 1VIG


RunningI

Ballasts

RLA

CS

CP

L

VS

At natural resonant frequency (Ω=1), the circuit behaves as a current source:

VLA

ILA

current source:

B

SLA Z

VIα

=

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Electronic Ballast DesignLamp Data @ 50kHz

VLA=30VrsmILA=0.8ArmsR 37 5 Ω

Ω=== 2008090

2//)2/320(4 πα

SB I

VZ

α = 0.9 Base Impedance

Ballasts

RLA=37.5 Ω ⋅ 8.09.0α LAI

mHf

ZLS

B 63.010502

2002 3 =

⋅==

ππ

nFZf

CBS

P 7.172009.010502

12

13 =

⋅⋅⋅==

παπ

nFZf

CBS

S 1.1592001.010502

1)1(2

13 =

⋅⋅⋅=

−=

παπ

Resonant Elements

Heating Frequency and Voltage (IH=0.7 Arms):

64.17.02002

14417.02002

144 2

=⎟⎠⎞

⎜⎝⎛

⋅⋅++

⋅⋅=ΩH RMS

H

SH VVV 7.60

177.11449.0

1 22 =−

⋅=

−Ω=

α √

Lamp Waveforms

Power

Ballasts

Power

Current

PLA23W

Voltage

20 V/DIV, 0.5 A/DIV, 5 μs/DIV

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Life extension of fluorescent lampsBallasts

The winner is:

ElectronicBallast with Rapid Start

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Outline


Digital Control of Electronic Ballasts

Primary

Digital Control

PrimarySource Ballast Lamp

Regulator SensorMicrocontroller

Discretization

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EMI Filter&

Power Supply

AC Line

Vbus= 320V

Vcc=15V

Vdd=5V

General Diagram of the UV Ballast

Half-Bridge Inverter

Digital Control

GateDriverIR211μC

ST6253

Freq

OC

Rs

UV LAMPGPH436T5

TemperatureSensor

DissolvedOzoneSensor

A1

A2

B1

B2

VDD

A/D

A/DNMI

A/D

ARTimer

GND

VbusSensor M1

M2

CF L

C

R1

R2A/D

Low-CostμC

B2

AD633Vlamp

Ilamp

Plamp

Analog Multiplier& Filter

Basic Microcontroller Circuitry+5V

+15VR4470

R5470

D2 D3

Reset

Display

Digital Control

ST6253

VDD9

VSS10

OSCin OSCout

XTAL8MHz

C115

C2

ARTIMout

TO IR2111

R347k

R147k

R24.7k

Rs47k

Cs220n

/RESET16

14 15

7

D11N4148

PB1 PB01 2

470

PWM

PWMSignal

15p 15p

Low cost microcontroller ST6253 with high noise immunityPower switches are driven directly from the MCUA 8MHz crystal is used for the MCU oscillator

Oscillator

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Half-Bridge Driver and Current Protection Circuit

+15VDb

BA157

+320V

Digital Control

IR2111

VCC

IN

COM

LO

1

2

3

4

PWMfrom MCU

VB

HO

VS

N.C.

8

7

6

5

Cb220n

Rg14.7

Rg24.7

Rs1

Rp11k

+5V

TO ResonantTank

Ra

M1IRF840

M2IRF840

Half-Bridge Driver

Dp1N4148

Cp100p

Rp212kTO NMI

pin 17 MCU

Ri2 15k

Ri1 10k

Ci 270n

+5V

Ra47k

Ca1n

LM393

Current Protection

Circuit

SensingResistor

Resonant Tank and Lamp Detection

Cs160n L

0.65mHTo lamp

From HalfBridge

A1

Resonant Tank

Digital Control

+5V

Rd2100k

Rd147k

Dd1n4148

Cd220n

20:1

Cp18nF

To lampelectrode B

To lampelectrode A

To pin PA0MCU

A2

B1B2

Lamp Detection Circuit

A LCC resonant tank is usedAn additional winding is used in the inductor to detect lamp presence

Lamp Detection Circuit

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Power Supply and EMI FilterPhase

VarV250

C11u/X1

18mH/

C210n/X1

C34.7n/Y1

C44 7 /Y1

Earth

L1

EMI Filter

Digital Control

Neutral 18mH/1A

4.7n/Y1

~

~

+

-

DB1A

v

C547u/350V

To HalfBridge

Vbus = 320V

Rdis100k

+15V +5V

Rl11k

Rl2120k

+5V

To pinPA2 MCU

Dl1n4148

L2

L1

L2

L1 To MCU

Input Stage for Resonant Inverter

C6330u

DB0.2

LM7805C810u

C9100n

L1

L2

To MCUSupply

C7330u

v

~

~

+

-

-15V

To Aux.CircuitsSupply

DC Power Supply

Lamp Power Sensing Circuit

To resonanttank

UV LAMP

Rb1 1kRb2 2.2k

+15

Cf 470n

Digital Control

R12/N27

6

To resonanttank

Ra4.7

Rb1 1kRb2 2.2k

AD6331X1

Y13

-15

8

52 4 6

7

-15

+15

-15

+15 Rf1 10k

Rf2 10k

PLAMP

To pin PA1MCU

+5

Df1N4148

TL081

Current Transforme

r

VLA

ILA

Multiplier

Low PassFilter

Lamp current is measured using a current transformerAn AD633 multiplier is used to obtain the lamp instantaneous powerA low pass filter is used to obtain the lamp mean power

r

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Microcontroller Programming

INITIALIZATION

RESETMainProgram

Interrupt

Digital Control

SOFT-START

LAMP DETECT ?

POWER REG

YES

NO

STOP PWM

NMI

WAIT 0.5 sec

RETIPOWER REG RETI

Watchdog register is programmed to increase robustness (TR=24.5 ms)Main routines are Soft-Start and Power RegulationNMI interrupt is used to implement overcurrent protection

Soft-Start Routine

100

Start

Heating

Freq(kHz)

Digital Control

80

7065605550

0.1 0.6 1.0 t(s)

Ignition ramp

Running

Autoreload register is used to generate PWMTwo registers are used, reload (RC) and compare (CP):

RCRCCPDuty

RCkHzf

−−

=−

=255255

8000)(

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Power Regulation RoutineA simple regulation routine is used in order to be feasible its implementation in the selected low cost microcontrollerThe reload register is modified in a value proportional to the

Digital Control

The reload register is modified in a value proportional to the error signal:

kkk eARCRC ⋅+= −1

RCkHzf

−=

2558000)(

8000)(

2fRCddf

=

If ek>0 (PLA>PREF) ⇒ RC ↑ ⇒ f ↑ ⇒ PLA ↓The regulation routine has been adjusted experimentally, final values are: A=0.5 and sample time of 0.1sThe switching frequency is limited within the range: 45-80 kHz

Power ResponseDigital Control

LampPower

Reference

180 V

230 Vrms

Line Voltage Step

8 W/DIV, 0.5 s/DIV

180 Vrmsp

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Laboratory prototypeDigital Control

Electronic Ballast for HID Lamp with Digital ControlDigital Control

Microcontroller:

PIC16F684 from Microchip, 14 pins, low cost.

8 bits, internal oscillator (8MHz), PWM module, A/D converter, and timers.

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Block Diagram

LampModel

Digital Control

26240454,2)()()( 2439

+==

sD

sIsG

pszsk

sisv

szL

LL +

+==

)()(

)(

Model

9654612,110387,1109,9)()( 2439 ++⋅+⋅ −− ssssD

Lamp current regulation in closed loop

The model includes lamp and ballast dynamic behavior

Design by SISOTOOL (Matlab):- A=12.5 - Phase Margin: 90º- Response Time: 100ms

Designing the Closed LoopDigital Control

p

ssR 5.12)( =

1

1

11)()()(

−

−

−⋅⋅

=−⋅

==z

zTAz

TAzEzDzR mm

11 81

−− += kkk DD ε

Discretization (Tm=10ms): Difference Equation:

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Simulation with Matlab SimulinkDigital Control

Simulation Results

Reference

Digital Control

Error

Regulator

Output

Perturbation

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Experimental Results

Lamp Current Lamp CurrentSteady State Transient

Digital Control

50 V/div – 0.2 A/div – 5 ms/div 250 V/div – 0.5 A/div – 20 ms/div

Lamp Voltage Line Voltage

Program FlowchartDigital Control

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Laboratory prototypeDigital Control

Lighting system with power line controlDeveloped by University of Oviedo

FILTERCOMM.

LIGHTING

MAIN SWITCHROOM SWITCHES

Digital Control

FILTERLIGHTINGMAIN SUPPLY

PCMASTER NODE

#1.1 #1.2 #1.3

#2.1 #2.2 #2.3

ROOM 1

ROOM 2

POWER LINE

PCADAPTER

#3.1 #3.2 #3.3 ROOM 3

Power Line is used as communication mediumSimple installation procedureAble to implement any control strategy

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Ballast Block Diagram

PFC ResonantI t400VM i

Lampss

Digital Control

Stage StageInverter

Power LineComm.

Neuron ChipControl

Comm.Bus

400V DC Bus

Mains

FREQ. LP1, LP2

s

Stage StageCo t o

CLK 10MHz

Management softwareDigital Control

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SchedulerDigital Control

SchedulerDigital Control

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Conclusions

Nowadays much energy is wasted in lighting due to the use of non-adequate lamp types or ballasts.q p yp

Lighting technology existing today allows saving up to 30-60% of energy.

Any good action taken or control strategy implemented, even being initially costly, will be paid back by the saving in electric consumption.

For large investments an economic study is crucial to determine the payback time

Thank you !

Asturias

Gijón

Universidad de Oviedo, E&E Eng. Dept. Industrial ...

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